High-Efficiency Transference of Electric Power – 11m Single Wire

In this second part on high efficiency transference of electric power, we take a look at the characteristics and power efficiency of a cylindrical coil TMT system where the transmitter and receiver coils are spaced further apart in the mid-field region. In this experiment a single wire transmission medium 11m long is used to separate the coils into different rooms at the laboratory, and a remote camera is used to observe the power at the receiver load measured by an RF wattmeter. Transference of electric power over 11m, and the characteristics of a TMT system coupled by the LMD mode at this distance, is shown to be remarkably different from the close mid-field region, and requires a very different setup and configuration of the experimental apparatus in order to optimise the efficiency of power transfer up to 96%.

In the close mid-field region with a 2m single-wire in the previous experiment on High-Efficiency Transference of Electric Power, the maximum transfer efficiency was achieved when the TMT system was configured, tuned, and operated at the point where the parallel modes were balanced, and the generator was optimally impedance matched to the system. It was conjectured that this balance contributes to maximising the power transferred from the generator to the twin-wire primary circuit TEM mode, to the single-wire LMD mode within the cavity formed between the transmitter and receiver secondary coils, and back to the twin-wire primary circuit TEM mode to the load.

In the mid-field region with an 11m single-wire we will see that this balanced mode setup leads to a maximum efficiency of ~40%. It is demonstrated that it is necessary to significantly mismatch the balance between the transmitter and receiver coils in order to get the LMD mode to extend across the single-wire transmission medium and restore transfer efficiency to over 90%. Transmitter and receiver primary circuit mismatch is mainly used to restore the transfer efficiency, along with fine adjustment through generator to TMT system TEM mismatch, measured at a range of Standing Wave Ratio (SWR) of 1, π/2, φ (the golden ratio), and 2.

The video experiment demonstrates and includes aspects of the following:

1. Small signal ac input impedance Z11 for a cylindrical coil TMT system in the mid-field region, and connected via an 11m 12AWG single wire transmission medium.

2. Z11 balanced parallel mode impedance measurements, for a reciprocal TMT configuration with 3 primary turns and matched primary capacitor tuning.

3. Z11 unbalanced parallel mode impedance measurements, for a non-reciprocal TMT configuration with 4 transmitter primary turns, 2 receiver primary turns, and mismatched capacitor tuning.

4. Transference of electric power from the linear amplifier generator to a 500W incandescent lamp load at the TMT receiver output via the reciprocal TMT configuration, and with a measured efficiency around 40%.

5. Transference of electric power to a 500W incandescent lamp load at the TMT receiver output via the non-reciprocal TMT configuration, and with a measured efficiency of up to 96%.

6. Demonstration of the high tension and associated discharge that can be drawn from the high-end of the receiver secondary coil, via the 11m single wire.

7. Transference of electric power efficiency measurements up to 96% (90% average) at 400W dissipated load power (peak 500W), in the 160m amateur radio band at 2.01Mc, and via an AWG12 single wire 11m long between the TX and RX coils.

Video Notes: The receiver power meter reading is shown on the inset video in the top right corner. For clear viewing and reading of the inset meter readings, and the VNWA software measurements, “720p” or “1080p” video quality is recommended, and may need to be selected manually from the settings icon once playback has started.

The experimental system circuit diagram, followed by an overview of the linear amplifier generator components is available here.

Figures 1 below show the key small signal input impedance characteristics Z11 presented in the video experiment, along with a more detailed analysis as to their impact on the observed and measured experimental results.

Fig 1.1. Shows the balanced and reciprocal input impedance for the cylindrical TMT system with 11m single wire transmission medium. The parallel modes, at markers M1, M2, M4, and M5, are balanced in the normal way by adjusting the primary tuning capacitors at both the transmitter and the receiver. The fundamental series resonant frequency M3 @ 2.02Mc has a series resistance RS = 11.3Ω, and is the primary drive point for the linear amplifier generator used in the experiment, with fine tuning around this point established at 2.01Mc as the optimum point. The parallel modes, one from the primary and one from the secondary, for both the transmitter and receiver coils are balanced, and show the frequency splitting that occurs when resonant modes of a very similar frequency are coupled together.

This form of impedance characteristic has been very well covered before in many posts on the website, and is discussed in detail in Cylindrical Coil Input Impedance – TC and TMT Z11. Previously these characteristics have been studied in the close mid-field region, typically with a single wire in the region of 1.5-2m long, or at least 2-3 times the diameter of the secondary coil, (0.5m in the case of the cylindrical TC). In this region the coupling between the transmitter and receiver coils, via the single wire transmission medium has been shown to be significant and the parallel modes split up to 200kc apart in frequency, as can be seen here. Within the split parallel regions there is a well defined and distinctive phase change from the extended series mode. The extended series modes, both upper and lower, can also be used as drive points for a linear amplifier generator, although the series resistance at these points is higher than the fundamental series mode, and ultimately will couple less total power from the generator through the TMT system.

With the single wire now extended to 11m in the mid-field region it can be clearly seen in this impedance scan that the coupling between the parallel modes of the transmitter and receiver has reduced, the frequency split is less at 30kc, and the extended series mode phase change is only just defined between markers M1-M2 and M4-M5. The fundamental series mode remains dominant at M3 and is the optimum drive point for linear amplifier generator. Overall the transmitter and receiver coils are coupled together by the single wire transmission medium in the TEM mode, but the coupling is reduced from the close mid-field region, and the additional impedance of the longer single wire is transformed back through into the transmitter primary and reflected in the increased series mode resistance at M3, RS = 11.3Ω.

Fig 1.2. Shows the effect of adding a 500W incandescent lamp load at the receiver primary coil output. The transmitter primary tuning capacitor CPTX has been adjusted from 663pF to 711pF in order to balance the transmitter parallel modes. The receiver primary tuning capacitor CPRX remains the same at 793pF. The resistive and inductive loading presented by the high-power incandescent lamp at the receiver has significantly changed the operating characteristics of the TMT system from a well balanced cavity, to a strongly unbalanced cavity, at least in terms of the TEM input impedance Z11.

The parallel modes of the receiver coil have been almost entirely suppressed with only a very slight presence at M3, and the overall resonant circuit properties of the receiver distorted and skewed away from the reciprocal coil characteristics of the unloaded receiver TC, to the characteristic shown at M3. It is important to note that this huge imbalance in the receiver end of the cavity in both the TEM mode, and I would conjecture the LMD mode due to the definite and distinctive change in the parallel modes, leads to a setup in this experiment where the transmitter end also needs to be unbalanced in order to reestablish the maximum efficiency in the transference of electric power. It is conjectured and discussed later that the setup change to the transmitter establishes a balance again in the LMD mode in the cavity when the total effect of the receiver and the longer single wire are taken into account together.

The fundamental series resonant mode has shifted down very slightly to 2.01Mc, RS = 13Ω, which was found to be the optimum drive point for the linear amplifier generator during the tuning and setup part of the experiment prior to the video experiment itself. The balanced reciprocal setup shown in figures 1.1 on this page, and 2.1 here , which was so effective in the close mid-field region, is shown to yield a maximum power transfer efficiency of now more than 35-45%. It is clear that the coupling introduced by the single-wire transmission medium and the impedance that this presents to both the TEM and LMD mode is critically important in both the setup and operation of a TMT system over distance.

Fig 1.3. Here the setup of the transmitter and receiver has been changed from that of the balanced reciprocal cavity condition, which yields power transfer efficiencies no higher than 35-45%, to the seemingly mismatched characteristic that yields measured transfer efficiencies up to 96% in the experiment. This setup requires the transmitter primary turns to be increased from 3 to 4, and a significant increase in the primary tuning capacitor CPTX = 1206pF. In correspondence, the setup of the receiver primary turns is also decreased from 3 to 2, and the primary tuning capacitor is significantly reduced to CPRX = 146pF. In this setup the input impedance Z11 for the TEM mode appears highly imbalanced, however for the LMD mode it is conjectured that a strong coupling and balance is re-established.

The fundamental series resonance at M3 has again only shifted very slightly in frequency to 2.0Mc, as the wire length of the experiment, the biggest contributor to this mode, remains constant, and with an increased series resistance RS = 22.8Ω. This still represents the best generator drive point for this experiment, with the lowest series resistance, and maximum coupling to the both the series and parallel modes that are active in this configuration. Transmitter parallel modes at M1, M2, and heavily suppressed around M3 and M4, are shifted quite considerably by the primary tuning capacitor mismatch. The dominant parallel modes, and hence conjectured to contribute most strongly to the LMD mode in the cavity, are now at M1 and M2 and involve both the transmitter and receiver, which will become apparent in the next figure. It should be noted that this figure is on a vertical magnitude of impedance scale of 4kΩ, whereas the previous figures where set to 1.5kΩ. This emphasises the very strong lower parallel modes and suggests that the transmitter pump action, from the generator to the LMD mode in the cavity, has been preferentially increased at this lower frequency of 1.2Mc.

The reduction in the primary setup at the receiver appears to have loosened the coupling between the primary and secondary coils of the receiver, which in turn has increased the Q of the free resonance in the secondary coil, increasing the phase change at M3, and emphasising the receiver characteristics transformed across the single wire cavity back to the transmitter. In short it appears like the LMD pump action into the cavity has been increased, whilst the Q of the receiver has also been increased. It is conjectured here that this combination of effects re-establish a balanced condition for the LMD mode, and hence a low impedance path for this mode across the cavity. With the LMD mode established across the cavity the efficiency of power transfer is pushed right back up to 95+%. Losses in the TEM mode are clearly increased with the longer single wire, but it is conjectured this is not the case for the LMD mode which is coherent spatially but not temporally over the entire cavity.

The split in frequency between the fundamental series mode at M3 and the upper extended series mode at M4 is now only 80kc, which is a very different condition than that which occurs in the balanced non-loaded mode. This close correspondence between these series two modes at the transmitter and receiver suggests part of the mechanism that allows very high-efficiency transference of electric power, where power is coupled from the primary to the secondary and hence into series modes to parallel modes, and then back through parallel modes to series modes at the receiver, a transformation across the TMT system from TEM to LMD and back to TEM mode in the load. Ultimately real power is passed from the generator through to the load which requires the TEM mode in both primary circuits, and the LMD mode as a result of the combined LM and LD modes across the cavity of the TMT.

Fig 1.4. Here we see a zoom of the peak of the dominant parallel mode from the previous figure at M1 and M2. Very interestingly we see that this peak is actually split into two peaks, suggesting two parallel modes that are dominant in both the transmitter and receiver but very weakly coupled. This now sets up the condition that we have two parallel modes separated by only ~ 1kc, and two series modes separated by only 80kc, from both the transmitter and receiver. I conjecture that it is this combination of series and parallel modes at each end of the TMT that makes it possible to yield very high-efficiency transference of electric power in this TMT system with a longer single-wire.

So what appears to be a loaded and unbalanced setup actually yields a TMT system that is balanced and matched for both the TEM and LMD modes combined. From a TEM perspective of the input impedance Z11 this appears to be heavily loaded and biased towards the transmitter, but on closer inspection and analysis suggests a configuration that balances the system between transmitter and receiver for maximum efficiency, minimum impedance for power transfer, and optimal conditions for the 500W incandescent load used in the experiment. Fine tuning of this configuration was further demonstrated by introducing a non-zero reflection coefficient from the transmitter primary circuit to the generator. This was accomplished by progressive adjustment of the antenna tuner away from the optimum SWR of 1.0, increasing up to 2.0.  A standing wave ratio of π/2 to φ (the golden ratio) were found to increase the efficiency slightly making the difference between a stable 90% efficiency up to a maximum in this experiment of 96%.

It is suggested here that the TEM mismatch at the transmitter primary circuit is a method of fine tuning the balance of the circuit for the TEM and LMD modes combined. The balance between these two modes, and hence the energy coupled into and between these modes, and across the complete TMT system and cavity, appears to have the most impact on the power transfer efficiency.

Summary of the results and conclusions so far

In this post we have experimentally observed high-efficiency transference of electric power sustained at 90%, and with fine tuning and adjustment up to a maximum of 96% with an estimated error of ±1%. The power was transferred using a cylindrical coil based TMT system, where the transmitter and receiver are coupled by an 11m single wire transmission medium. 400W of power could be stably passed from the linear amplifier generator to the incandescent load at maximum transfer efficiency (90-96%), and up to 500W was tested at a reduced efficiency ~85%. From the experimental results and measurements presented the following observations, considerations and conjectures are made:

1. The “ideal” balanced reciprocal cavity setup, optimal in the close mid-field region, is not efficient for optimum power transfer in the more distant mid-field region, and most specifically when driving a heavy load at the receiver output.

2. An unbalanced TEM setup at the transmitter and receiver coil appears to restore the overall combined balance of the TEM and LMD modes across the entire TMT system restoring the high-efficiency power transfer characteristics in the mid-field region.

3. The unbalanced TEM setup appears to increase the LMD pump action into the cavity, whilst the Q of the receiver has also been increased by loosening the primary receiver coupling. It is conjectured here that this combination of effects re-establish a balanced condition for the LMD mode, and hence a low impedance path for this mode across the cavity.

4. The Z11 impedance characteristics in the unbalanced setup and when loaded at the receiver with a 500W incandescent lamp show a fine split between the series modes and the dominant lower parallel modes, which appears to show the transmitter and receiver coupled together in both the TEM and LMD modes

5. This close correspondence between these modes at the transmitter and receiver suggests part of the mechanism that allows very high-efficiency transference of electric power, where power is coupled from the primary to the secondary and hence into series modes to parallel modes, and then back through parallel modes to series modes at the receiver, a transformation across the TMT system from TEM to LMD and back to TEM mode at the load.

6. The maximum transfer efficiency could be fine tuned by mismatching the generator to the primary transmitter circuit and hence creating a reflection coefficient in the transmitter part of the system. SWRs in the region 1 to 2 were tested, with the best results around π/2 to φ (the golden ratio).

7. It is suggested, but needs considerable further work to develop, that the impedance presented by the single-wire transmission medium to the LMD mode is not the same as that presented to the TEM mode, and where a narrow single wire to the limit of the skin depth would appear as a high impedance at the driving frequency to the TEM modes, this is not the case for the LMD modes. For the LMD modes (LM and LD) the single-wire appears as a low impedance monopole waveguide which is spatially coherent over the extent of the cavity.

This experiment has opened up a range of interesting questions that need further consideration and considerable investigation to answer and progress, and most particularly from conclusion 7; to understand and establish in more detail the impedance presented by a single-wire transmission medium to the LMD mode generated in the cavity. It would also be interesting to compare the single-wire to a Telluric transmission medium, which will be the focus of the next experiment in this series. This experiment will look at transference of electric power over a 40m single-wire where the transmitter and receiver are in separate buildings of the lab, and also to compare the measured performance to a Telluric connection between the two via a basic ground system at each end.

Click here to continue to the next part, looking at Transference of Electric Power – Single Wire vs Telluric.


1. Tesla, N., Colorado Springs Notes 1899-1900, Nikola Tesla Museum Beograd, 1978.

2. A & P Electronic Media, AMInnovations by Adrian Marsh, 2019,  EMediaPress

3. Dollard, E. and Energetic Forum Members, Energetic Forum, 2008 onwards.


 

The Wheelwork of Nature – Fractal “Fern” Discharges

Sooner or later research into the underlying nature and principles of electricity must inevitably lead to those larger philosophical and esoteric questions surrounding the origin and purpose of life, its mechanisms that constitute the wheelwork of nature, and our purpose and part to play as very small cogs in this grand design. I have in previous posts started to tentatively touch-on and develop my own current understanding of the wheelwork of nature through ideas, designs, experiments, and conjectures regarding displacement and transference of electric power. This post is the first in a sequence looking at experiments in electricity which reveal or suggest clues about this underlying wheelwork, with the associated phenomena and results, their possible origin and purpose, and how we may form a synchronicity with this wheelwork, and hence benefit from a journey that increases our knowledge and awareness of our-self and that of the great mystery or grand design. This first post in the series looks at the wheelwork of nature – fractal “fern” discharge experiment, along with observations, measurements, and interpretation.

For a summary recap on how I see the principles of displacement and transference of electric power, and the conjectures that I have already made based on the experimental work reported so far, I recommend reviewing Displacement and Transference of Electric Power, Tesla’s Radiant Energy and Matter, the Transference of Electric Power category, and the overall Introduction to this website. The essence of this definitive journey was so well articulated by Nicola Tesla, in what is for me one of his greatest statements, and which should have both enormous and far reaching impact on the efforts of our research into the wheelwork of nature, and the underlying principles and mechanisms that constitute this wheelwork: “Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic – and this we know it is, for certain – then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature.”, Tesla[1].

In this statement Tesla shares his unwavering believe that it is only a matter of time until we will attach our experiments, apparatus, and machines directly to the wheelwork of nature, not if, but when. And how close have we gotten to this vision ? It would seem to me that in the field of electricity research as a whole, a little progress may have been made, but we still seem quite far from accomplishing this monumental task of understanding, and making a shift of focus from measuring voltages and currents on the bench in an apparatus seemingly unrelated to the wheelwork of nature, to an inclusive and intuitive approach where the workings of our apparatus reflect the underlying wheelwork in the natural world. In order to accomplish this I believe it is a necessity to work at building a bridge between the Philosophical/Esoteric and Scientific disciplines, through looking at electrical phenomena with fresh eyes and with a mind open to grasping an understanding of the underlying principles and mechanisms across seemingly diverse and seemingly different disciplines.

Science in our current times considers the field of electromagnetism to be almost entirely understood and explained, with any further exploration aimed at the successive dissection of smaller and smaller detail. Whilst science has developed a successful model to explain the outer form of electromagnetism, and the principles and equations required to utilise this field in engineering, this is only a good observation and measurement of the outer form, with all the underlying quality and richness of this subject yet to discover. In this post I intend to start this process by including conjectures regarding the experimental results and phenomena that cross these multi-disciplinary boundaries, and hence take those small steps on the long road to building a bridge of understanding and ultimately greater awareness of our own inner world and that of nature. Whilst this will not appeal to some that read this post, for others it may trigger ideas and different ways to consider and interpret the results of our experiments, and open the possibility for new discovery of the inclusive hidden world ever present in our daily endeavours.

In understanding Tesla’s statement it would seem important to first get a grasp on what constitutes the wheelwork of nature, and how we go about attaching our endeavours to it. In an effort to impart some of what I think and feel on this topic I will use the experiment to be presented in this post as an example, which with all best intent may shed but a little light on the vast unknown darkness that lies ahead of us on this journey. In this post I will be looking experimentally at a Tesla coil (TC) experiment first demonstrated by Eric Dollard[2], using his Integratron apparatus in 1978. The apparatus generated a “fern” like discharge, one quite distinctly different from the normal range of “lightning” like discharges emitted by the majority of TC apparatus and experiments.

This “fern” discharge is particularly interesting when viewed as a form of fractal, which may also have golden-ratio geometry associated with it, where the filaments and tendrils formed along the primary streamers have an impulse like nature, are momentarily transient and orthogonal in nature, and the overall growth and pattern of the discharge is reflected in naturally occurring forms. These combined together indicate to me that this experiment may lend itself well to exploring and gaining a better understanding for the wheelwork of nature, or in other words, the underlying principles and mechanisms that lead to the generation of this exciting result. Since Eric’s original experiment there appears to be little public knowledge available on the details of how to generate this phenomena, the apparatus and operating conditions required to call-forth or reveal this type of discharge, and considered analysis and conjecture on how this phenomena occurs, and what it can show and tell us regarding the wheelwork of nature.

In this post I will be experimentally demonstrating this phenomena in a two-part video experiment, looking in detail at the apparatus and setup required to generate this discharge, along with analysis of the TC impedance characteristics, and some preliminary consideration as to the meaning and relevance of this phenomena. As way of introduction directly to the results, figure 1 below shows a side-by-side comparative image of Eric’s original experimental result, and the discharge obtained in the experiment presented in this post. It can be seen that the discharge in nature and form are equivalent.

If we study these images carefully looking at the similarities and differences then we start to see a most astonishing result, that many of the features occur in the same proportion and with same intrinsic detail. The primary tendril grows vertically in the centre and is essentially the same form with the same curve, sub-tendrils emerge at similar points along its length, and micro-filaments are ever-present orthogonal to the main structure. The second main tendril to the left, (allowing for some 3D rotation on axis), follows a similar pattern with corresponding bifurcations and sub-tendrils along its length, as do the other smaller tendrils and filaments around the breakout point.

When considering electric discharges, what are the chances that two different experiments, with different coil systems, materials, and components, and different generators operated with unknown differences, will produce two discharges that are so very similar in geometric structure, form, and nature ?  If the nature of the discharge is essentially random both spatially and/or temporally, then it would seem most unlikely, but if there are underlying guiding principles at work then it would seem quite possible, provided the same set of principles are involved in both experiments. These underlying guiding principles I am referring to as the wheelwork of nature, and this experimental series is intended to see what can be discovered, understood, and applied in attempting to attach these experiments to the very wheel work of nature!

This experiment uses the Plate Supply, yet to be covered in detail in the Tube Power Supply Series, as the high tension generator, combined with a dedicated coil system consisting of a single Russian GU-5B power triode, and a nominally designed 3.5Mc conventional style Tesla coil. The TC is designed and arranged with a tightly wound and coupled primary and secondary coil geometry, specifically intended for high voltage magnification and the generation of discharge streamers. The design deliberately steers clear of any design proportions involving the golden ratio or optimisations suitable for the transference of electric power in a TMT system, and this is intended in order to emphasis the quality of the experimental result generated by underlying principles in the wheelwork of nature, rather than outer geometric proportions arranged to demonstrate any particular result.

Part 1 of the video experiment demonstrates and includes aspects of the following:

1. Introduction to the wheelwork of nature experimental series based on Nicola Tesla’s famous quotation, and Eric Dollard’s original “fern” discharge experiment.

2. Brief Introduction and consideration of the importance and implications of the bridge between the Philosophical/Esoteric and Scientific disciplines, through grasping an understanding of the underlying principles and mechanisms of the wheelwork of nature.

3. Overview of the tube plate supply generator, GU-5B coil system, and Tesla coil to be used in the experiment.

4. Design and construction considerations important to a high-frequency 3.5Mc Tesla secondary coil, suited to discharge experiments in the wheelwork of nature.

5. Primary coil drive circuit apparatus using a series feedback class-C Armstrong oscillator, tuned to the lower parallel resonant mode at 2.6-2.9Mc, and matched for best power transfer from the generator.

6. The “fern” discharge phenomena at various generator power output levels from 100W – 2.2kW

7. Observation of the characteristics of the “fern” discharge including fractal like self-repeating, self-similar tendrils, golden-ratio like proportions in the tendrils, orthogonal emitted sub-tendrils, and orthogonal displacement like micro-filaments and fibres.

8. Symmetric and reflected discharge patterns in geometric space, including tendril growth and extinction, and temporally based non-random, sequenced and repeating discharge patterns indicative of a defined “dance” routine.

9. Conjecture of an underlying dynamic and guiding pattern and order to the “fern” discharges, and hence a tantalising and astonishing view of part of the underlying mechanisms of the wheelwork of nature.

Part 2 of the video experiment demonstrates and includes aspects of the following:

1. Experimental variations to part 1 of the experiment in order to see if the nature and form of the fractal “fern” discharge could be changed to another form

2. Tuning the coil system down to 2.1Mc on the lower parallel resonant mode, whilst observing the discharge form.

3. Tuning the coil system up to 4.0Mc on the upper parallel resonant mode, whilst observing the discharge form.

4. Tuning the coil system across the transition between the lower and upper parallel resonant modes, whilst observing the discharge form.

5. Changing the blocking/tank capacitor at the output of the plate supply from 25nF 25kV to 30uF 8kV.

6. Changing the plate supply output from a bridge rectified waveform with blocking capacitor, to a raw unrectified waveform with no blocking capacitor.

7. Adding a toroidal top-load to the Tesla coil and retuning the lower parallel resonant mode to 2.28Mc, whilst observing the discharge form

8. Replacing the single GU-5B power triode with parallel connected dual 833C power triode tubes.

9. Observation using the dual 833C triodes at the upper parallel resonant mode at 3.9Mc of a tighter and more rounded fractal “fern” discharge, with shorter, more rounded, and more numerous tendrils.

Figure 2 below shows the schematic for the experimental apparatus used in the video experiments. The high-resolution version can be viewed by clicking here. The tube plate supply is not included here and will be covered subsequently in another post.

Principle of Operation and Construction of the Experimental System

The plate supply is configured with two high voltage (HV) microwave oven transformers connected in series to produce at maximum load 4.2kV @ 800mA, and up to 6.5kV unloaded. From the GU-5B datasheet the maximum anode potential is rated at 5kV for frequencies less than 30Mc, so two transformers in series are adequate when driving the experiment in CW (constant wave) mode. Although not covered in the datasheet the GU-5B can withstand considerably higher anode voltages up to ~ 8-9kV when driven in a pulsed mode with a low duty cycle, which considerably improves the forward pressure supplied to the primary coil. In this experiment I use only CW mode in order to simplify the generator drive characteristics, and to minimise variations in the circuit that could further mask the origin of the discharge phenomena to be explored.

The output of the HV transformers can be configured to a variety of different stages in the plate supply, including raw output, bridge rectified, or level shifted. In this experiment I predominantly use the bridge rectified output to provide an all positive unipolar electrical pressure to the coil system. For experimental variation I also demonstrate the raw output of the transformers which supplies the SCR controlled portion of the sinusoidal transformer output, up to the full sinusoidal output at maximum input power. In this experiment the purpose of the generator is to supply sufficient voltage swing across the primary to ensure high voltage magnification at the top-end, whilst also supplying adequate current in the primary circuit so there is strong magnetic induction field coupled between the primary and secondary coils, and hence the discharges are hot, white, thick tendrils that can be readily observed, measured, and studied.

At the output of the plate supply is the blocking/tank capacitor which is intended to protect the plate supply components, such as the semiconductors in the bridge rectifier and the power control SCR, by preventing voltage spikes and oscillation from the primary resonant circuit from being reflected back into the power supply. This can happen very easily e.g. if there is a poor impedance match between the generator (tube anode) and the Tesla coil, or during tuning experiments the tube stops oscillating, or oscillation becomes unstable between the upper and lower parallel resonant frequencies. In the basic experiment a 25nF 25kV pulse capacitor is used as the blocking/tank capacitor at the output of the power supply, which is raised right up to 30µF 8kV for the variation experiments.

The positive output from the blocking capacitor is fed via a short length of AWG 12 silicon coated, micro-stranded, low-inductance cable to the primary coil circuit, which consists of the 7.5 turn primary coil and a KP1-4 10kV vacuum variable capacitor 20-1000pF connected in parallel. The connections between the primary coil and the primary tuning capacitor are AWG 8 silicon coated, micro-stranded, low-inductance cable, and the inter-connections on the top of the coil system on both sides of the primary coil are made with copper busbars and 4mm high voltage terminals. The other end of the primary coil circuit is connected directly to the anode of the GU-5B tube, again using the same AWG 12 low-inductance cable.

The complete primary circuit from the plate supply back to ground is connected using low-inductance heavy duty cable in order to reduce inductive reactance losses in the primary circuit, and hence maximise the potential difference swing across the primary coil. In this experiment the ground connection is simply the line earth provided to both the plate supply unit, and the coil system unit. For simplicity, and hence maximum clarity on the experimental phenomena, no rf ground was used separately to the grounding of the units to the line earth. So the return line for both the generator drive via the GU-5B and plate supply, the secondary coil bottom-end, and the pickup coil bottom-end are all connected directly together by the line earth.

In order to simplify the TC drive from the generator the GU-5B is arranged as a Class-C Armstrong oscillator, which derives feedback from the secondary coil resonation via a 4-turn pickup-coil which is positioned under the primary coil, and isolated from the primary and secondary by a nylon plastic platform at the base of the TC. The pickup coil feeds the charging circuit in the grid circuit of the tube. Correct polarity and selection of the grid capacitor combined with the parallel discharge rheostat will enable the tube to oscillate at the selected and tuned parallel resonant mode.

The principle of operation of this form of tube driven series feedback oscillator is covered in detail in the post Vacuum Tube Generator (811A) – Part 1. In a tube driven primary coil circuit it is important to maximise the voltage swing across the primary coil, and at the top-end of the tube anode, whilst ensuring maximum power transfer from the generator to the primary circuit. This is accomplished by ensuring that the anode resistance of the tube during operation is arranged to be as close to the resistance presented by the primary coil at either the upper or lower parallel resonant frequency that is being used. This is then fine-tuned for optimum power transfer by adjusting the grid feedback bias.

When driven by this type of oscillator with feedback directly from the secondary coil resonation, the oscillation will centre around one of the two parallel modes presented by a tuned primary-secondary Tesla coil. The different modes that result from the close coupling of a primary and secondary coil, are well covered, measured, and explained in Cylindrical Coil Input Impedance – TC and TMT Z11. The design of the Tesla coil itself for this experiment will be covered next, along with the usual small signal ac input impedance characteristics Z11, in order to understand the TC impedance properties and characteristics, the best match and driven point for the experiment, and the range of tuning that is available for variations in the experiment.

Figures 3 below show a range of pictures of the experimental system, including some of the construction details of specific interest, and some of the variations to the initial basic setup of the experiment.

Secondary Coil Design, Considerations and Construction

The design of the Tesla coil always starts with the characteristics of the secondary coil to define its series fundamental resonant frequency ƒOSS), and the geometry of the coil suitable for the type of experiment to be undertaken. Design considerations for Tesla coils are considered in detail in the post Tesla Coil Geometry and Cylindrical Coil Design. For this experiment ƒSS without any top-load or wire extension, was designed nominally to be in the 80m amateur radio band at 3.5Mc. The geometry for the coil is to be tightly wound with many turns e.g. > 100 in order to maximise magnification of the dielectric induction field across the secondary length, and which is well suited to discharge streamers of a good length and intensity at the break-out point at the top-end of the secondary coil. When grounded at the bottom-end, which represents a lowering of the bottom-end impedance, the secondary will appear as a λ/4 resonator where the series mode resonant frequency ƒSS is dominated by the wire-length and series self-capacitance of the coil. The accompanying parallel resonant mode will be at a higher frequency than the series mode, and is dominated by the inter-turn inductance and inter-turn capacitance of the coil.

The tightly wound secondary geometry with many turns has an aspect ratio of 5:1 so the coil is tall and narrow and well suited to high voltage magnification at the top-end. A suitable piece of 3″ diameter irrigation pipe was available in the workshop which had a measured diameter of 76mm.  The complete design of the coil deliberately avoids any golden-ratio proportions in the aspect ratio of the secondary, the conductor diameter to the conductor spacing of the windings, and the drive parallel resonant mode frequency to the series mode frequency. This intentional omission of the golden-ratio is intended to simplify the interpretation of the experimental results, by removing considerations of influences that may arise from golden-ratio relationships between the experimental apparatus and the underlying principles of the wheelwork of nature. Subsequent variations to the basic experiment can then be added e.g. a Tesla coil that includes golden ratio proportions but has a nominally designed equal series fundamental resonant frequency at 3.5Mc, in order to compare the results and observed phenomena for golden-ratio influences and/or principles.

Tccad 2.0 was used for a rapid and approximate indication of the electrical and resonant characteristics of the secondary coil, the detailed results of which are shown below in figure 4. The wire selected for the secondary coil is a good quality silicone coated multi-stranded conductor, the silicone coating being very good both thermally, and as an insulator to prevent breakouts and breakdown from the upper turns of the coil to the lower ones. A standard electrical wire size 1mm2 (1.1mm diameter) with a total diameter of 2.45mm (nominally 2.5mm in the specification) was found to be ideal for the design proportions, and also avoids any golden-ratio winding proportions in the design.

The parameter “Winding Height of Secondary Coil” on the turn period of 2.45mm, (“Wire Diameter” 1.10mm + “Spacing Between Windings” 1.35mm), was used to adjust the number of turns in the secondary until the “Approximate Resonant Frequency” was closest to the desired 3.5Mc, and in this case was calculated to be 3493.87kc. Since we are running the secondary coil without a top-load, and with many tightly coupled turns, the “Secondary Quarter Wavelength Resonant Frequency” will be far from that required, in this case at 2025.26kc, the difference in the two also indicating that there will be a reasonably wide difference in frequency between the series and parallel resonant modes of the secondary.

In this experiment the secondary coil is to be driven magnetically coupled to a primary coil as per a standard and conventional Tesla coil arrangement, and which is well suited to being driven by variably tuned upper and lower parallel modes by a feedback oscillator. Since a spark gap generator is not being used, which requires very high oscillatory currents in a tuned primary tank circuit, the secondary coil could be driven directly by the generator without a primary coil, and at the series fundamental mode. This would require an output transformer to transform the high plate resistance of the tube to the low series resistance of the secondary coil at resonance. Whilst this latter method is a more efficient and matched drive at the series resonant frequency, it also adds additional complexity in the output matching transformer, and the controlled output frequency from a linear amplifier drive.

Primary Coil Design, Considerations and Construction

For this experiment, simplicity of Tesla coil drive was selected in order to minimise influence on the final results, and hence a standard primary-secondary Tesla coil arrangement was used. The primary coil is a standard tightly wound multi-turn geometry with a heavier gauge wire than the secondary coil, nominally again a good quality silicone coated, multi-stranded conductor, and of a standard electrical wire size of 2.5mm2, and with a total diameter of 4.0mm. The diameter of the coil was set at 130mm using acrylic tube, which results in a reasonably tight magnetic coupling to the secondary, and hence good power transfer from primary to the secondary, combined with excellent voltage magnification properties, and all very well suited for large and powerful discharges at the top-end. The number of primary turns was defined as a balance between the magnetic coupling and the tuned parallel mode frequency when combined with the KP1-4 primary tuning capacitor. 7.5 turns was found as an optimal balance between the magnetic coupling, a suitable tuning range of the primary variable capacitor to cover both the upper and lower parallel modes, and physical connection of the electrical outputs to the input busbars on both the +ve and -ve sides.

This form of primary is very well suited to a generator which is based on a driven oscillator or linear amplifier. In this type of generator which is often vacuum tube based, (or semiconductor based), the drive frequency of the generator is arranged to be at a specific point in relation to ƒSS dependent on the series or parallel mode to be driven, and the primary circuit consisting of the coil and parallel tuning capacitor are not arranged to be resonant to the selected mode of the secondary. In this case the primary currents are much lower than in a spark-gap primary tank circuit, but nonetheless transfer maximised power from the generator to the primary based on a reasonable impedance match of the tube plate resistance to the high parallel resonant mode resistance. In addition, no attempt has been made to design the primary circuit for equal weights of conductor with the secondary coil, thereby also simplifying the included design principles, and in principle simplifying the interpretation of the measured results.

From repeated operation of the coil system in discharge experiments, the gauge and design of the primary has been found to get quite hot when running at high input powers up to ~ 2.5kW, and for sustained time periods e.g. > 1-2 minutes in CW mode. Pulsed mode improves this further, but was not used in the basic form of the apparatus, to again not complicate the possible interpretation of the experimental results. Later experiments use a re-designed primary of the same diameter but with much heavier gauge windings e.g. AWG8 or 12 silicone coated micro-stranded wire, and a naturally convection cooled coil wound on support posts, rather than a solid acrylic tube. Details of this improved primary coil will be presented in subsequent experimental posts.

Overall, the design of the primary and secondary, both electrically and mechanically, were arranged to be able to cope with a high drive input power from the plate supply, which provides hot white discharge streamers at the top-end of the secondary. These powerful discharges of good length and definition make it much easier to observe, identify, and study their form and geometric structure over extended time periods, and the designed apparatus lends itself directly to the purpose of uncovering the wheelwork of nature. This is in itself a most important principle in understanding what it means to “hook” our apparatus to the wheelwork of nature, or in other words apparatus suitable for such discovery must be designed, constructed, and operated with deliberate intent and purpose to this end. In this way it becomes possible for the intent and purpose of the operator and apparatus to reflect and attune to specific vibrations within the wheelwork of nature, revealing new in-sight, knowledge, and understanding!

Small Signal AC Input Impedance Measurements

Figures 5 below show the small signal ac input impedance Z11 measured directly on the experimental system, and using an SDR-Kits VNWA vector network analyser, as used on many experimental pages on this site. The measurement setup, equipment, and connection to the experimental apparatus is shown in figures 4.14 and 4.15.

To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Fig 5.1. Shows the input impedance Z11 over the range 500kc to 5Mc for the secondary coil series connected to the VNWA, and with a 1m earth extension at the negative terminal of VNWA to lower the impedance at this point, and ensure a λ/4 resonator measurement, whilst maintaining the secondary coil as unloaded as possible. The series measurement of the secondary enables its characteristics to be measured with minimal variation brought about from coupling with the primary, and hence the cleanest results for the characteristics of the secondary alone. The magnitude of Z11 (blue curve) show clearly the series fundamental resonant mode ƒSS (secondary-series mode) at marker M1 at 3.44Mc, and series resistance RS = 118.2Ω, and the corresponding phase change from an inductive to capacitive reactance characteristic of a series resonant circuit. At ƒSS the phase of Z11 (red curve) Ø is ~ 0°, and shows that the secondary coil is a completely resistive impedance, where the frequency of this mode is dominated by the wire length of the coil combined with its overall self-capacitance and series resistance.

The parallel resonant mode ƒSP (secondary-parallel mode) occurs at marker M2 at 4.01Mc, and again has the characteristic high resistance RP ~ 76kΩ with a phase Ø ~ 0°, that corresponds to resonance that results from a parallel resonant circuit, and in this case dominated by the inter-turn inductive reactance, and the inter-turn capacitive reactance. It is most characteristic for a Tesla secondary coil of many different geometries to display this dual series and parallel modes, and which makes this form of coil most suitable to a wide range of driven and operating conditions, with a variety of different types of generators. The impedance characteristics of a Tesla coil are measured and explored in detail for the input impedance in Cylindrical Coil Input Impedance – TC and TMT Z11, and for the transmission gain in Cylindrical Coil Transmission Gain – TC S21.

It can be seen from this initial series measurement of the secondary coil that its measured properties correspond well with the designed characteristics, where ƒSS at 3.44Mc deviates only by ~1.5% from the Tccad results at 3.49Mc. The span from the series to the parallel mode from 3.44Mc to 4.01Mc spans entirely the 80m amateur radio band of transmission. It is also to be noted that when compared with the cylindrical coil measured in Cylindrical Coil Input Impedance – TC and TMT Z11, that the quality factor Q, of this coil is considerably lower. This can be identified easily by the sharpness of the phase transition at ƒSS and will reflect much more noticeably into the primary coil Z11 characteristics of the system as seen by the generator. The lower Q results predominantly from the tightly wound geometry of the secondary coil. the high aspect ratio, the large number of turns. and hence the increased series resistance of the secondary coil at series resonance. The reduced Q however, does not impact on the intended experimental purpose of this system, but is interesting to note on the geometry differences of coils explored on this website.

Fig 5.2. Simply shows fig. 5.1 on a magnified vertical impedance scale (1000Ω per division), and emphasises the details of the series fundamental resonant mode ƒSS at marker M1. This mode forms a very clean and stable drive point suitable for a frequency controlled linear amplifier generator either driven directly from the generator without  a primary coil, or via a primary coil, and in both cases with an output transformer and matching stage. In this experiment we drive the parallel modes using a series feedback oscillator in order to simplify the drive circuit, reduce possible experimental system influences, and allow for wide and easy primary circuit variation, and hence self-tracking and tuning frequency control.

Fig 5.3. Here we have now combined the primary and secondary coils directly in the arrangement that they will be driven by the generator. The VNWA acts as the generator and drives the primary as a λ/2 coil, and the primary tuning capacitor CP has been removed from the circuit so we can see the basic coupled interaction between the primary and secondary coils. The secondary top-end now includes the short copper breakout point, and the bottom-end is grounded to the line earth circuit used in experimental operation. In other words, other than CP being disconnected from the primary, the circuit is identical in connection and arrangement to that driven by the generator in the video experiment. We can see that in this primary-fed measurement ƒSS at marker M2 has now shifted down considerably from the free resonance of the secondary on its own at 3.44Mc to 3.18Mc. This is most directly a result of the increased wire length when the secondary coil bottom-end is connected to the experiment line earth. The series resistance at resonance of the secondary RS = 118.2Ω is now transformed into the primary and added to the series impedance of the primary circuit, results in series mode impedance of ZP = 176.1Ω. This is an impedance rather than a pure resistance at resonance as the  phase relationship is skewed slightly by the tight coupling of the secondary and primary.

The parallel mode, as is characteristic when a primary coil is added, has flipped to a frequency below the series mode, and now forms with interaction from the primary, the lower parallel mode at marker M1 at 3.09Mc. The upper parallel mode from the primary coil is at a frequency above the upper end of the scan at 5Mc. This is as a result of the primary tuning capacitor CP having been disconnected, making the self-resonance of the primary coil based on its inductive reactance, and very low self-capacitance, pushing the self-resonant frequency much higher than the bandwidth of this result. When CP is added back into the circuit the upper parallel mode will reside inside the bandwidth of the scan and forms another possible driving point of the system. It can also be clearly seen in this scan the much lower Q factor of the tightly wound and coupled coil arrangement. The compared cylindrical coil which is loosely wound, and with lower primary to secondary coupling factor exhibits a much higher Q, and is much more suitable to experiments in transference of electric power demonstrated particularly in the High-Efficiency Transference of Electric Power experimental series.

It should be noted that there is a slight inflection in the impedance measurements at ~ 3.65Mc which results from connection to the line earth system, and indicating a slight resonant interaction with the earthing system. This interaction continues through the rest of the characteristics but is very minor and not expected to influence the experiment in any significant manner. When the line earth connection was removed and replaced with a long wire extension at the base of the secondary coil this slight inflection does not appear in the characteristics, as can be seen in figs. 5.1 and 5.2.

 Fig 5.4. Shows the characteristics of the coil system when tuned to the optimum driven point used in the video experiment. This optimal point is based on using the GU-5B vacuum tube, and when stability, coupled output power, and dissipated power, are all taken into consideration empirically during operation. The primary tuning capacitor has been set to CP = 231.4pF, and it can be seem that the lower parallel mode ƒL is strongly dominant at marker M1 at 2.71Mc. The series resonant mode ƒO is stable as before at M2 @ 3.18Mc, and the upper parallel mode ƒU is suppressed at M3 @ 3.36Mc. During part 1 of the video experiment the lower parallel mode operation point was stably used at input powers over 2kW to demonstrate the nature of the fractal “fern” discharge, and varied in measurement from ~ 2.65Mc to 2.75Mc, a good correspondence to the impedance measurements at this driven point. At M1 the primary resistance RP ~ 10.6kΩ is reasonable match to the anode resistance of the tube, and when fine adjusted using the grid bias rheostat. At this operating point it is demonstrated that significant power can be coupled from the generator to the Tesla coil, and with the formation of hot white fractal “fern” discharges up to 30cm in length.

Fig 5.5. Here the primary tuning capacitor CP = 164pF, and has been tuned to the point where the upper and lower parallel modes are balanced in impedance and essentially if the coils where uncoupled the two parallel modes, one in the secondary, and one in the primary, would occur at the same frequency. The series resonant mode remains stable with only a very slight shift to 3.17Mc. When driven using a series feedback oscillator, as is the case in this experiment, this would be an unstable drive point where oscillation would flip backwards and forwards between the upper and lower parallel points from 3.79Mc down to 2.94Mc. In practise it is possible to wind the tuning from the stable lower parallel frequency below 2.94Mc up through the balanced point and up above 3.79Mc to a stable upper parallel frequency, which is demonstrated as one of the variations in part 2 of the video experiment spanning a frequency range from 2.1Mc up to 4Mc, and back down again.

Fig 5.6. Here the primary tuning capacitor has been further reduced to CP = 124.3pF, and the upper parallel mode is now dominant at 4.07Mc. The series mode remains unchanged at 3.17Mc, and the lower parallel mode is now suppressed at 3.02Mc. In part 1 if the experiment it was difficult to get the GU-5B to oscillate at the upper parallel mode, even given the strong dominance  of the upper parallel mode. If we look at the primary resistance at M3 we see that RP significantly increased to ~ 25.7kΩ, which takes it outside of a reasonable match to the anode resistance of the tube. Even by reducing the grid bias to increase the anode resistance the upper parallel mode did not prove to be a stable operating point using a single GU-5B tube, and where considerable power could be coupled from the generator to form discharges at the top-end. In part2 of the video experiment where dual 833C triode tubes were used in place of the single GU-5B, the upper parallel mode could be stably tuned and significant power could again be coupled to the Tesla coil to produce fractal “fern” discharges of a varied nature at 4Mc.

Fig 5.7. Shows the lower limit of operation which could generate even a very small discharge in the video experiment, when the primary tuning capacitor CP was increased to 470.3pF. The lower parallel mode is strongly dominant at M1 @ 2.01Mc, the series mode remains largely unchanged at 3.16Mc, and the upper parallel mode is almost entirely suppressed at 3.66Mc. Below this point the GU-5B could not oscillate and no discharge could be generated at the top-end of the coil. At this point the lower parallel mode is almost 1.2Mc away from the series mode, and considerable increased forward potential from the generator would be necessary to observe even a small discharge at the breakout.

Fig 5.8. For comparison with a fixed door-knob capacitor this result shows the vacuum variable capacitor replaced with a 466.7pF door knob. Positions of upper, lower parallel, and series modes remain largely unchanged. The Q of the resonance  is slightly increased by using the door-knob rather than the vacuum capacitor, but otherwise there seems little other advantage to using the door-knob instead of the vacuum variable capacitor, at the currently used generator potential and output power. The door-knob does have a higher voltage rating at 15kV, and this would be significant if running the generator with level shifted output up to 9kV in order to generate longer tendrils in the discharges. Otherwise the vacuum capacitor with a high-Q and 10kV nominal rating is most suited to the variations of tuning that can be accomplished in this experiment.

Overall the small signal input impedance characteristics Z11 for the coil system show good correspondence with the actual operating points, and allow for the accurate selection of required generator drive point,  and the necessary impedance matching required to transfer maximum power from the generator to the Tesla coil secondary in the configuration selected for the experiment. The magnitude of the voltage swing the tube can provide across the primary coil has a big impact on the length of the discharge tendrils generated at the top-end of the secondary, and the magnitude of the current the tube can pass through the primary circuit, combined with strong magnetic induction field coupling to the secondary, has a big impact on the strength of the discharge streamers. In this case hot, white, thick filaments from strong primary currents, combined with long tendrils from high top-end potentials are ideal for the observation and measurement of phenomena demonstrating the wheelwork of nature.

Fractal “Fern” Discharges

Figures 6 below show a range of high-definition pictures taken close-up to the top-end of the secondary throughout the experiment. The pictures have been selected to illustrate the range of different fractal forms that are observed in the experiment, and the various features and characteristics that accompany each form variation. All discharge pictures are based on the same scale size, so they can be readily compared for height and width between the various geometric forms. Sequences of pictures were taken on the same operating run, and with the same configuration and tuning of the coil system facilitating direct comparison of each discharge one to the next.

From taking many photographs of the discharges during operation, and looking through them in detail, it is clear that the discharge forms are not just random, but follow various patterns and hence can be grouped together according to their observed characteristics. The images in figures 6 have been collected together to represent the range of different types of discharges observed. Although here only two images of each are shown, there are mostly numerous examples of each form amongst the recorded images. The main observed groups are presented below, but first a consideration of the common features of all of these fractal “fern” discharges:

Common Features

All of the discharges appear as a self-similar, self-repeating structure that consists of tendrils emerging from either the breakout point as a primary tendril, or a sub-tendril (secondary, tertiary etc.), which emerges orthogonal from the parent tendril. An individual tendril at any level appears to progress from its emergence straight or with minor curve for a reasonable extension, before starting a clearly defined curve towards a centre point, and it could be conjectured would continue in ever decreasing arcs in the form of a spiral, if the plasma discharge within the tendril were able to extend further in the medium. Indeed some of the tendrils have been observed to curve almost 3/4 of a complete revolution at their outer extremity. Emerging tendrils along the length of any parent tendril also appear to emerge at similar proportions along the length of the tendril, when tendrils are compared one to another. Almost all emergence of major sub-tendrils appear orthogonal to the parent tendril, with the exception of very small tendrils that also display some bifurcation particularly, but not exclusively, towards the outer tips of the tendril extension.

In all the discharge pictures the start of the discharge appears to be at the breakout point, and the extinction process of a tendril also appears to support this. This may appear as obvious, but needs to be considered carefully when we take into account the emergence and growth of this patterned discharge. For example, terrestrial lightning has been shown to be a combination of a sky discharge, and a land based streamer extending from the ground upwards to meet the down-coming discharge, which is yet an area of considerable research and exploration. All the tendrils start from a hot-white plasma-like extension indicative of significant RF currents in the discharge which produce a very high-temperature plasma in the core of the tendril. As the tendril grows outwards and the plasma is cooler it takes on the characteristic purple-blue colour of a weaker discharge state. The outer tip of the tendrils often ends in a group of tiny filaments extending outwards along the trajectory of the tendril, often curving with reduced radius to a seemingly invisible centre point at a conjectured centre point.

The major tendrils are wrapped in many tiny orthogonal filaments which are present along the entire length of the tendrils, and most interestingly appear relatively constant all the way back to the very hot emergent point close to the secondary breakout. The filaments very numerous in quantity take on a bluish-purple hue somewhat different to the tip-ends of the tendrils. It appears that the purple of the tip-ends would occur from the diminishing intensity of the tendril far from the source point, whereas the bluish-purple hue of the tiny filaments appears constant along the length of the tendril irrespective of the intensity of the tendril at that point, the filament being only proportional in length to the intensity of the tendril.

As can be observed in the videos the discharge does not sound as an aggressive crack or discontinuous voluminous sound similar to a lightning discharge, but takes on a rather pleasing and peaceful hum that could be likened to a plasma discharge in a spark gap. This peaceful hum implies that the discharge is free of discontinuous breakdown events, where ionisation of the surrounding medium occurs within very short time periods in a random impulse like discharge, but rather as an established quiescent, balanced and stable process that is capable of repeating and regenerating itself from one moment to the next.

In all the images taken of the discharges there are many examples of equivalent geometric proportions, non-symmetric and symmetric pattern formation, sequences of similar geometric forms leading from one to another, (in the limit of the current photography and filming equipment), and the overall impression of a discharge process that is well organised, orchestrated, and manifested, and one that reflects choreographed and regenerative behaviour emanating from an invisible and underlying set of unknown principles and processes. What follows next are the noted recurring yet different geometric forms. To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Tall, Narrow, Curved and Non-Symmetric

Figures 6.1 and 6.2 show this form of discharge where a single central primary tendril curving in any direction at the upper limit of its vertical travel. This form tends to be tall and narrow in width, dominated by a single central tendril, and with smaller other primary tendrils extending out from the base. In this form secondary tendrils emerging from the primary tendrils are usually much smaller, and much less developed than the primary ones. It appears as though the majority of the energy in this discharge is focussed on the primary or root tendril, and enables considerable vertical height to be accomplished, at the expense of not spreading out sideways, or the development of major sub-tendrils. In the experiment operation the major tendril in this form was noted to extend to over 30cm in height from the breakout.

Tall, Narrow, Straight and Non-Symmetric

Figure 6.3 shows an example of this more unusual discharge, in that it was rarely seen in the image sequences. In this case there is again a tall and narrow form, but the there is very little curvature at the end of the main tendril. The main tendril tends to be less developed in sub-tendril detail, and even the tiny filaments seem much less numerous and present along its length. This main vertical tendril tends to come to a sharp and well defined point, without bifurcation or parallel filaments at its outer extremity. Again this form was on occasion measured to over 30cm long. In this particular picture the straight vertical main tendril is accompanied by another well developed tendril to the left which displays all the common elements of most discharge tendril.

Wide, Low, and Symmetric

Figures 6.4 and 6.5 show a group whose form is very distinct and different from those yet discussed, and is in my opinion one of the most beautiful image groups I have yet taken of the fractal “fern” discharge. In this group there is always a very high degree of vertical symmetry from repeating and self-similar patterns that grow out horizontally from the breakout point. Here in this example the symmetry is very well developed between the two primary tendrils that emerge equally left and right from the breakout. Indeed the symmetry is so good that one could almost place a mirror down the vertical axis and reflect either side to the other. The proportions of emergence of sub-tendrils are very similar on all the major tendrils, and also secondary and even tertiary tendrils are much more highly developed than in other groups. The secondary tendrils here are well developed and repeat with high intensity the same self-repeating structure of the parent. Bifurcations at the outer extremities are more numerous in this group, and often the tiny filaments more defined, and more easily distinguished along the length of the tendril.

Furry with Numerous Sub-Tendrils and Filaments

Figures 6.6 and 6.7 show a very interesting group of discharges that appear furry or fuzzy as a result of the numerous mini sub-tendrils, and more numerous tiny filaments along the length of the major tendrils. This is similar to Eric Dollard’s original image which also appears quite furry from the numerous tiny filaments. This “furriness” can appear in any of the other geometric forms and is most easily spotted from the many mini filament between the mini sub-tendrils. Here in figure 6.6 this is observed on a symmetric structure, where 6.7 shows the same characteristics on a tall and narrow structure. Characteristic to this form are also many sub-tendrils that emanate numerously along the length of the major tendril, but also themselves bifurcate often at their tips producing mini fan-like structures. The fan-like structures give the impression of movement or vibration within the form, and helps to illustrate the intricacy and dynamic detail that is present in these fractal “fern” discharges.

Double-Wound “Vortex” Vertical Tendrils

Figures 6.8 and 6.9 show another very interesting geometric group which consist of double-wound tendrils, like a vortex, vertically extending from the breakout upwards, before splitting apart to develop further detail, tendrils, or bifurcations at their upper ends. In figure 6.8 the tendrils spread out at the top and form similar secondary tendrils. In figure 6.9 the tendrils split from the vortex but follow a similar trajectory and form to the outer limits of their extension. This vortex form is most usually tall and narrow, and consists of two primary tendrils of very similar intensity, where sub-tendrils can also be emitted outwards during the vortex stage. This form is often accompanied by tendril symmetry either horizontal or vertical, and most pronounced after the tendrils have split from their wound trajectory.

Tendril Extinction

Figures 6.10 and 6.11 show examples of tendril extinction, so what happens when a fully developed tendril starts to collapse. These pictures appear to support the notion that discharges emanated from the breakout point expand outwards, and when the available energy in the tendril is exhausted the tendril terminates at the breakout point first before extending outwards again as the remaining energy, at a distance from the breakout, is consumed. The extinction of a tendril appears analogous to an exhaust plume after the ignition and burn process, as the plasma collapses along the length there is left a residual ionised trail in the air. The extinction of a tendril is also an interesting process in and of itself as it suggests the question … Why, when a streamer or tendril has been established, would more energy supplied to the top-end of the secondary coil, simply not continue to “pour” through the low impedance channel opened by the tendril in the medium ?  I suppose the answer to this lies in understanding the underlying causes of these discharge forms, the guiding principles in the wheelwork of nature, and the specific vibrations that gives rise to the dynamic formation, behaviour, and extinction of these forms.

After now looking at the currently observed geometric forms so far, it is necessary to look also at the temporal sequence of geometric forms. This part of the results and analysis is preliminary, as it could benefit greatly from improved high-speed photography and video equipment in order to observe slow motion video, and photographs with very short time intervals, but is presented here in order to give an idea that there is both a defined temporal sequence, pattern, and I would even go so far at this stage to suggest a “dance” that emerges within the discharge sequence. By “dance” I am referring to repeated and correlated sequences in both the geometric and temporal dynamics of the discharge, rather than a randomly occurring an unrelated collection of lightning like discharges.

Figures 7 and 8 present two such temporal sequences over different time spans, but taken with successive and rapid (for the equipment used) images. Figure 9 shows a side by side comparison of the these sequenced images all together, to give a clearer visual impression of the patterns being referred to. When combined together and compared, a pattern could be conjectured to exist at a geometric and temporal level in these results, although this conjecture would be greatly strengthened when very slow-motion video, and very high speed photography is available. Again all sequences in the following figures are taken on the same scale, in the same operation run, and at the same experimental setup and operation parameters.

Overall from the time sequences it could be conjectured that there is a choreographed “dance” taking place, in this case from the images taken with the current equipment available, that over a time period the dance goes as follows:  1. reach upwards as high as possible – 2. branch out sideways in a symmetric way –  3. bend to the left (or right) – 4. bend the other way –  5. twist around and rotate, before starting the sequence over again. As previously said, high speed video and photography will show if this really is the case, although it is most interesting at this stage in the exploration to even consider that there might be a geometric and temporal sequence to this dynamic discharge process, and another interesting insight in to the possibilities presented by the grand design and the underlying wheelwork of nature.

The final images in this post in figures 10 show a simple preliminary fit of the tendril end curve to the golden spiral rectangle model. As previously shown almost the entire majority of primary and secondary tendrils, (other than those fewer examples in the narrow, tall, and straight group), have a curve at the end of the tendril that appears, if extrapolated, to wind into an ever decreasing radius like a spiral to a centre point. The first section of the tendril is usually straight, either outwards from the breakout point, or orthogonal to the parent tendril before starting to curve gently in a downwards fashion. After a given expansion outwards the tightening of the curve begins, and it is this curve that is interesting to see how closely it adheres to the golden spiral or fibonacci spiral. For this fit two images were selected that are considered to have tendrils that are square on to the camera, that is, they are not rotated out of plane, and hence the curve becomes distorted in the image by perspective. In each of these images the rectangle model for the golden spiral is scaled and added over the top of the images, and fitted if possible to the extent of the visible tendril. The overlay golden spiral rectangle model[3] curve being in blue, whilst the rectangle boundaries are in grey, and the construction guide lines of the rectangles in red and green dotted.

So now that we have reached this point, what do all the experimental results, measurements, and the observed phenomena show us about the wheelwork of nature ?  And what can we then say about how to “attach” our machines to this wheelwork ? If we now make a more detailed consideration of the subtle features of the results, and conjecture on both its scientific and philosophical implications, then this may start to become clearer.

Fractal Nature

The overall nature of the discharge displays a fractal like structure, that is, a seemingly never ending structure where the pattern of any part of the structure is self-similar and repeated across different scales. It can be seen that from any primary streamer or tendril, a secondary tendril emerges which is a smaller copy of the same geometric structure as the primary tendril. In some cases a tertiary tendril can be seen emerging from this secondary tendril, which is again a smaller copy of the same geometric structure as the secondary and primary tendril. It is conjectured that at any scale that the discharge could be observed, the bifurcation of the tendril is repeated with self-similar structure and characteristics in its nature and form.

A fractal is also a mathematical shape with well defined equations, and can be precisely modelled to show its self-similar structure at any scale. Many different forms of fractals are found throughout the natural world[4], and appear to form a basic building block which repeats its order and structure to form vast and complex macroscopic forms from the smallest microscopic form. This in itself suggests interesting qualities that for me relate to purpose for the wheelwork of nature. The microscopic to macroscopic self-similar geometry suggests that the inner and outer worlds, that is, what you can see, and what you cannot see, are connected and joined as a reflection of one another independent of scale. So we might conjecture that what we perceive in the outer world, is directly reflected within nature’s own hidden world. The law of light and reflection in this case would imply that if we can perceive an event or experience on the outside, then we somehow and somewhere can find that reflected on the inside, as is above is below, as is without is within. If we care to take an objective, open, and considered look at any aspect of nature as a tiny cog in the overall wheelwork, then it is not so difficult or unrealistic to see the correspondences between these inner and outer worlds.

From a philosophical standpoint, what can we not learn about nature’s hidden principles and life in general, from the perspective that the macroscopic is showing us something truthfully reflected to the microscopic ? Is this not a hint as to how to “attach” our experiments and machines to the wheelwork of nature ? I would conjecture and propose that it is, on the basis that principles and mechanisms that we find in our experiments, apparatus, and machines can be corresponded to principles and processes that relate directly to how we sense nature’s hidden world, and that more fundamentally the converse is true, that what we create or destroy in the outer world is only a reflection of the intent, principles and processes going on inside. When we see the correspondence of both the inner and the outer then we establish a synchronicity with the natural order, our tiny cog meshes directly with the wheelwork of nature, and our machines function directly in tune or “tuned into” life’s fundamental processes. So I would propose that, to attach our machines to the wheelwork of nature they must embody basic natural principles and laws, and have a purpose which reflects an intent that is inclusive, life-supportive, and inter-dependent.

Golden Spiral/Ratio Geometry and Proportions

From the results presented in figures 10, it can be conjectured that the curve of the tendrils displays a tentative fit to at least a section of the golden ratio proportion when using the golden spiral rectangle model, for which the ratio between its length and width is the golden ratio in each quarter turn. This model produces a repeating spiral which whilst not truly logarithmic, is a close approximation to the golden spiral. The golden spiral is in principle a logarithmic spiral with a growth factor determined by φ, the golden ratio, and increases in width by the factor of φ for every quarter turn of the spiral[5]. The spiral exhibits self-similar structure in the same way as for the fractal in the previous section, and in principle repeats constantly at the same ratio at any scale from the microscopic to the macroscopic. The golden ratio and spiral is very well explored and documented[6], at least as a mathematical and naturally occurring geometric structure, and which has been deliberately incorporated into man-made geometric and artistic constructions, where it is said to create an natural, intuitive, and aesthetically pleasing visual proportion.

For me the possible presence of the golden spiral proportion in the discharge suggests that again the phenomena, and the apparatus that has revealed or stimulated this result, is in some way again “tuned into” the wheelwork of nature. It is interesting to note that the designed geometric proportions of the TC system were not designed on the golden ratio either in height to width of the secondary, inter-turn spacing to conductor diameter of the secondary, or in arrangement with the primary proportions and wire. It could be speculated, and it is a speculation at this time, given the lack of any confirmation from direct measurement, that the dielectric and magnetic fields of induction, Ψ and Φ could be related to each other in the golden proportion.

Both induction fields exist in and around the discharge and their relationship itself may be in the golden proportion which in itself determines the path and geometric curve of the streamer. When one considers a wide range of different possible discharges from a TC system, dependent on coil geometry, fundamental resonant frequency, and generator drive method and envelope, it would seem very likely that the nature and structure of the discharge could be strongly dependent on the relationship between the induction fields Ψ and Φ. This is an area that would benefit from a much more comprehensive study into the diversity of structure and form of a TC streamer, its principles, mechanisms, and key causative parameters, along with of course the specific relationship between Ψ and Φ, and how the discharge materially manifests, in energy, space, and time.

Another seemingly small detail to note is the “apparent” direction of growth of the spiral like tendrils. A superficial look at any of the discharges presented in this experiment would easily lead the observer to consider the generator as the source of the tendril, and the surrounding environment to be the sink of the tendril, or in other words the tendril extends from the HT tip at the top of the secondary and grows outwards from this tip into the surrounding environment, its length dependent on the HT electrical pressure from the accumulated charge at the top-end of the secondary. On further consideration of the fractal nature and tentative golden spiral fit,  it could be conjectured that the source of the spiral is actually within the microscopic and that the discharge is pulled out of the breakout point and disappears into the hidden inner spiral, or we may even consider it to be a form of vortex. This could be supported by the tendril extinction images where the major tendrils are seen to terminate from beginning through to the end-tip, also lending to the analogy of being called-forth or “pulled” from the experiment, rather than being “pushed” out from the experiment. This conjectured reversal of source and sink brings up interesting possibilities as to the origin or source of the discharge, the process of creation and destruction, and the nature of polarity and potential, all important areas worthy of considerable further exploration and discussion.

Orthogonal Filaments, Disruptive Discharges, and Displacement

Vassilatos[7] gives a most interesting account of one of Tesla’s very early experiences with radiant energy when he observed that a high voltage DC when suddenly applied to an electrical circuit, such as in long cables in power transmission, or when a high voltage DC dynamo was connected to the rails of a railway track with a distant load, it produced a very brief and transitory, “hedge of bluish needles, pointing straight away from the line into the surrounding space”. The important aspects that we consider here from this are that the bluish needles were firstly always orthogonal to the conductor, and that they were only briefly transitionary, that is, until the electrical pressure from the DC source had been distributed across the extent of the electrical circuit.

It is similar arguments and conjectures that I have used for displacement, that this is an underlying guiding mechanism and principle that is ever present within the inner workings of electricity, but is only revealed and hence observable, when a non-linear transient change in an electrical system imbalances the equilibrium of the electrical circuit to such a degree, that displacement must act in order to “accelerate” the dielectric and magnetic fields of induction into their new equilibrium conditions, and in so doing emitting a secondary emanation, or what Tesla called radiant energy. Consideration of the mechanisms and processes involved in what I have termed displacement and transference of electric power appears in many posts on this website, and is introduced in detail in Displacement and Transference of Electric Power.

The correspondence and similarity I make in our current considerations of the experiment in this post, and hence to the mechanism and process of displacement, results from the tiny orthogonal filaments that accompany all of the major tendril activity in the discharges. These micro filaments appear as a “bluish hedge”, and are ever present surrounding the tendrils. It appears from the furry group of discharges that the dynamic nature of the discharge is more agitated, more in motion, and changing on a shorter transient time period. Now, it cannot necessarily be concluded at this early stage of exploration into the wheelwork of nature that the “bluish hedge” is the same in both Tesla’s observation, and in this reported experiment, but it can certainly be speculated on and conjectured that it is the same underlying principle of displacement, resulting from the dynamic transient changes in the relationship between the dielectric and magnetic fields of induction, Ψ and Φ, that is observed in both experiments.

The forward pressure of the discharges, pumped by the generator on successive cycles, charge accumulated at the top-end of the cavity in the secondary coil, and the dielectric induction field magnified to a high-potential at the top-end, all result in an momentary explosive outward pressure in the form of a discharge into surrounding space, a “disruptive discharge” as Tesla called it[7]. This disruptive discharge by its very nature has already unbalanced the surrounding electrical equilibrium of the common medium, calling forth the same guiding principle of displacement that we have been hitherto discussing. The orthogonal filaments or “bluish hedge” are the visible phenomenon of a displacement event, that provides the needed balancing force as the energy in the discharge is absorbed or “sunk” into the surrounding medium, or to conjecture through insight alone, is “sucked” or “pulled” out of the common medium by the spiral-like vortex that exists at the end of each of the active tendrils, and transferred back into the aetheric medium. With the energy of the tendril transferred, the balance of the common medium has been restored, before another explosive and disruptive event begins. Such is the process of displacement of electric power, and of course much work and observation required to confirm or not the validity and scope of the conjectures I am making here.

Vibration, Resonance, and Frequency

In all the variation experiments so far undertaken in this experimental post the only parameter that made a difference to the observed discharge phenomena was the ability to drive the experiment stably at a higher frequency. Resonating at the lower parallel resonant mode the discharge geometry and form where observed to be the same for both the GU-5B, and the 833Cs. At the upper parallel resonant mode the geometry of the discharge was tighter, the tendrils were smaller, more numerous, and with more sub-tendrils, in short the phenomena was more “dense”. However in both upper and lower parallel modes the nature of the phenomena was the same, and it is conjectured that the same underlying principles, and relationship between the dielectric and magnetic fields of induction existed. In other words the vibration of the phenomena and its associated qualities are the same in both cases, whilst the variation of density was brought about by a change in frequency, a specific quantity that reflects one of the parameters of vibration. This now brings about probably the most important distinction that needs to be made in the consideration of this experiment, that is, the differences between vibration, resonance, and frequency.

It should be clear thus far in this exploration that I am referring to vibration as a most fundamental expression of nature, everything has an underlying vibration in life, from galaxies, to suns and planets, to human beings, animals, plants, minerals, to scientific experiments, apparatus and equipment, natural laws and principles, and of course to the very wheelwork of nature itself. In this grand diversity vibration suggests the qualities that together constitute the form to which they are attributed. The very vibration of a collective form determines its purpose, inter-actions and relationships not only to itself but to the common medium surrounding the form, and of course to other forms. It is through the qualities of vibration that any collective form relates to the world around it, and is either attracted or repelled from any other form.

Such is the rich quality of vibration, and the apparatus required to attune to the surrounding vibration powered by the wheelwork of nature. It is through tuning to these vibrations, that we can establish resonance with or between other manifested forms. Resonance then is depicted here as the intelligent cooperation or interaction between at least two forms vibrating with a shared and common purpose. Through resonance potential can be transformed to action, as the voltage accumulated on a capacitor, can be transformed to current flowing in a circuit, and the storage of a magnetic field in an inductor, and back again, as energy is passed backwards and forwards between two electrical components, two forms vibrating together with shared electrical characteristics, qualities, and purpose.

The frequency of the vibration represents only one scalar quantity that is easily measured in this experiment. In the basic experiment the lower parallel resonant mode was at ~ 2.7Mc and this is but one quantity of a quality related to time, that defines the nature of the results obtained here. But it is not enough to characterise the phenomenon entirely by saying, the only parameter that matters in this experiment is the frequency at which the secondary coil was designed to resonate at, so in other words frequency could tell us how but not why! Yes, the frequency of the secondary coil is important, for if another coil is made at say 300kc it will not show the fractal “fern” discharge phenomenon, so rather it is the qualities underlying the 300kc coil that define the vibration of the phenomenon, and hence the nature and the form of the discharge. So the designed and operated frequency of the secondary coil is but one parameter in a set that represents the specific qualities of the vibration that is observed as the fractal “fern” phenomena in this experiment.

The task ahead in working to understand the wheelwork of nature is to reveal, discover, and explain the qualities that underlie any particular vibration, and then to design and develop apparatus that can reflect that vibration in its operation. By doing this we would have attached our apparatus to the wheelwork of nature, and phenomena will be called forth according to the vibration attuned through resonance that we have intended in the purpose of the apparatus. If the purpose of the apparatus is for our own exploration and utility of the world around us, then I could also imply that our apparatus is only a reflection of our own vibration, purpose, and qualities, and hence the circle of life is complete in the acquisition of self-knowledge through discovery, experimentation, and relationship.

Such are my philosophical and esoteric considerations on the wheelwork of nature, but it should now be clear to the reader of this post, that if the wheelwork of nature is to be progressively uncovered or dis-covered, and its unknown secrets to be under-stood and harnessed then we must look beyond the face value of the outer form of our experiments and apparatus, and the single viewpoint that science can reduce the richness and diversity of the great mystery to a simple explanation of the outer form. The outer form is only but the reflection of the inner principles, qualities, and mechanisms that constitute its purpose and place in the inner world. It is this hidden or inner world, or the wheelwork of nature, that we must turn our attention and endeavours to, and in so doing start the long journey to the re-unification of science, philosophy, and the esoteric.

Summary of the results and conclusions so far

In this post we have presented an apparatus and experiment which generates a fractal “fern” discharge, and I have suggested that this form of phenomena is suitable for the exploration of the wheelwork of nature, based on my interpretation of a quote originally made by Nicola Tesla. The fractal discharge presented in both experimental videos has been carefully observed and measured, and a range of conjectures put forward to the signifiance and relevance of the results to the underlying wheelwork of nature being explored. Specifically the experiment has demonstrated, suggested, and conjectured that:

1. The biggest variation in the experiment is frequency, and that even a standard Tesla coil designed and operated over the frequency range of interest, combined with a generator suitable to supply sufficient forward pressure and power to the Tesla coil, will display a discharge in the form of a fractal “fern”.

2. The discharge in this experiment clearly demonstrates fractal like properties, and shows a partial fit in the discharge tendrils to the golden spiral and proportion, despite these proportions or considerations not being included in the Tesla coil or generator design and construction.

3. It is suggested that the fractal “fern” discharge consists of both spatial and temporal order, originating from underlying unknown principles which are conjectured to be directly principles from within the wheelwork of nature.

4. It is suggested that the tiny orthogonal filaments observed along the major tendrils are related to the principle of displacement of electric power, an underlying principle in the wheelwork of nature, and one that also relates closely to reports from Tesla’s own work.

5. It is conjectured that the fractal “fern” discharge phenomena results directly from the relationship between the dielectric and magnetic fields of induction, and this relationship is defined by the underlying qualities of the vibration, which is a part of the principles of the wheelwork of nature.

6. It is conjectured that the scalar quantity of frequency, found as the key dependent parameter so far, is actually only a small piece of an underlying vibration, which is in and of itself, made up of a range of different qualities.

7. It is conjectured that vibration, resonance, and tuning are key to understanding how to attach our apparatus to the wheelwork of nature, and hence become part of a synchronicity that may extend across many levels and layers of existence.

It is clear from these conclusions that this first experiment in the series is a simple departure point, and considerable further experimentation, measurement, and consideration is required to support or refute the conjectures advanced here. Experimentally next key steps would include:

1. A more extensive experimental study with Tesla coils of different resonant frequencies and geometries, which would start to reveal the different types and forms of possible discharge phenomena, and their underlying causative conditions and parameters.

2. Identification of additional variations in the experimental system, and particularly including the relationship between voltage and current in the generator drive and primary circuit, along with the envelope and type of drive waveform, and comparison with different types of generator e.g. a spark-gap generator.

3. Development of a measurement technique to gain a clearer representation of the relationship between the dielectric and magnetic fields of induction during operation of the experiment.

And finally for this first post, high speed photography and video would facilitate a deeper look into the suggested “order” and “choreography” of the phenomena, and perhaps a clearer view of how its vibration and underlying qualities are related to the Wheelwork of Nature.

Click here to continue to the next part, looking at The Wheelwork of Nature – Vibration, Frequency, and Discharge Form.


1. Tesla, N. Experiments With Alternate Currents Of High Potential And High Frequency, An address to the Institution of Electrical Engineers, London, February 1892.

2. Dollard, E. Discharge Experiments using an Integratron, Bolinas, California, 1978.

3. Parks Photos. Golden Ratio Overlays, 2015,  ParksPhotos

4. Mandelbrot, B. The Fractal Geometry of Nature, W. H. Freeman and Company, New York, 1983.

5. Wikipedia. The Golden Spiral, Wikimedia Foundation Inc., Wikipedia, 2021.

6. Meisner, G. The Golden Ratio – The Divine Beauty of Mathematics, The Quarto Group, New York, 2018.

7. Vassilatos, G. Secrets of Cold War Technology – Project HAARP and Beyond, Adventures Unlimited Press, Illinois, 2000.

8. A & P Electronic Media, AMInnovations by Adrian Marsh, 2019,  EMediaPress

9. Dollard, E. and Energetic Forum Members, Energetic Forum, 2008 onwards.


 

The Wheelwork of Nature – Vibration, Frequency, and Discharge Form

In this follow up experiment in the Wheelwork of Nature series we take a look at vibration, frequency, and discharge form that results from a set of Tesla coils designed to cover an operating frequency range between 300kc and 4Mc. If you have not done so already I recommend reading or reviewing the first experiment in this series The Wheelwork of Nature – Fractal “Fern” Discharges, which will set the basis for this current experiment. In the original experiment a range of experimental variations were tested in order to identify the origin of the fractal “Fern” discharge form, which is a distinct and significant departure from the discharge form normally observed in Tesla coils constructed using a basic standard design format, and constructed with readily available materials and processes. Variations to the experiment included, changing the matching and tuning of the Tesla coil, the excited resonant mode, the generator waveform, the type of vacuum tube used as a generator, and a top-load on the Tesla coil. The only significant variation to the discharge form was noted between the upper and lower parallel resonant modes of the Tesla coil, and hence it was concluded that frequency, or more correctly vibration, of the Tesla secondary coil was key to the nature and form of the fractal “fern” discharge.

The original coil was theoretically designed with a series resonant mode frequency of the secondary ƒSS ~ 3.5Mc in the 80m amateur radio band, and was subsequently measured using a vector network analyser to have a series fed fundamental resonant frequency ƒSS = 3.44Mc. When this was combined with a primary coil and RF ground it was found to reduce to ~ 3.18Mc. The upper and lower parallel resonant modes were found to be around 2.7Mc and 3.4Mc. The generator used was a basic class-C Armstrong oscillator using a single GU5B vacuum tube, and dual 883C vacuum tubes in the variation generator. This form of generator will oscillate readily at the upper or lower resonant parallel modes and can be tuned over a frequency band using a vacuum variable capacitor as a parallel tank capacitor in the primary circuit. This gave a tuned range from low end of the lower parallel mode at ~ 2.4Mc to the high end of the upper parallel mode at ~ 3.6Mc. Across this entire tuned range the discharge form was the fractal “fern”. The only significant variation was at the upper parallel mode, where the fractal “fern” appeared more compact, tightly formed, and with more dense secondary and tertiary tendrils.

In this next experiment the exploration of vibration and frequency is extended across a much wider range by using a set of Tesla coils that are designed on the same geometry, with the same materials, but with different wire type and gauge, and hence the fundamental series resonant mode changes with the wire length. Originally five coils were designed and constructed, with series resonant mode frequencies of ƒSS ~ 357kc, 570kc, 1013kc, 2068kc, and the original at 3494kc. The general design characteristics of the coils, key measured, operating and tuning characteristics are summarised in figures 1 shown below, and explained in detail later in this post.

In practise, when using a self-tuned feedback oscillator as the generator, the lower frequency coils tend to preferentially oscillate at the 2nd or 3rd harmonic frequency around 1Mc, where the gain of the vacuum tube generator is higher, and the capacitive loading in the primary is lower. Increasing the tank capacitance to tune the fundamental of these lower frequency coils, significantly capacitively loads the vacuum tube generator reducing the Q of the system dramatically, and making it very difficult to oscillate in class-C mode. Ideally the two lowest frequency coils would be driven directly at the series resonant mode frequency ƒSS, however this drive strategy is not best suited to the scope of this experiment where variable frequency adjustment during operation is preferred. As a result of this, and without wanting to significantly change the generator and matching for this experiment from the previous one, the three upper frequency coils only are demonstrated in the video for this experiment. In practise that proved to be more than adequate to demonstrate the transition of the discharge form, from the fractal “fern” discharge, to the more standard “swords” form, which is commonly observed for a standard Tesla coil design when driven by a vacuum tube generator.

The video experiment demonstrates and includes aspects of the following:

1. Three secondary coils based on the same geometry, dimensions, and construction, with different wire gauge and hence wire length, producing a different fundamental series resonant frequency in each secondary coil.

2. A standard vacuum tube Tesla coil generator (VTTC), operated in CW mode using a pair of 833C vacuum tubes (VT) arranged in parallel as a tuneable class-C Armstrong oscillator.

3. The tube power supply (HV & Plate) configured for 2 series transformers with a nominal output of 4.2kV @ 0.8A, 3.3kVA, HV bridge rectified, and with 25nF 25kV blocking capacitor at the output, and operated up to 3kW line input power.

4. Secondary coils with nominal fundamental series resonant frequencies of ~ 3.5Mc, 2.0Mc, and 1Mc, could be easily exchanged, tuned, and matched to the VT generator.

5. The 3.5Mc coil operated over a range of 2.4-3.3Mc, shows the fractal “fern” discharge over the entire frequency band. A tighter and denser fractal “fern” was observed across the upper parallel mode.

6. The 2.0Mc coil operated over a range from 1.5-2.3Mc, shows the fractal “fern” discharge at the upper parallel mode, and the “swords” discharge at the lower parallel mode.

7. The 1.0Mc coil operated over a range from 970kc-1.4Mc, shows the “swords” discharge over the entire frequency band.

8. The transition from fractal “fern” to “swords” occurs between 1.8-2.0Mc, where the “sword” discharge retains slight curvature until frequencies < 1.5Mc.

9. Conjecture that the variation of discharge form may result from the changing vibrational qualities within the relationship between the dielectric and magnetic fields of induction at different frequencies, and hence part of the underlying principles and mechanisms within the Wheelwork of Nature.

Principle of Operation and Construction of the Experimental System

The experimental apparatus uses the same high voltage plate tube supply from the pervious experiment, configured in the same way with two series transformers, bridge rectified, and with a 25nF blocking capacitor at the generator output to protect the semiconductors of the bridge rectifier. The design, construction, and operation of this high voltage tube supply is covered here Tube Power Supply – High Voltage & Plate. The generator itself uses the dual 833C tube board with the tube supply heater unit as an class-C Armstrong oscillator, both of which were used in the variation experiments in the first part of this series, and are covered in detail in Tube Power Supply – Heater, Grid & Screen. The dual 833C tubes proved to be more flexible over a wider frequency band than the single GU5B based generator used in the primary Wheelwork of Nature experiment. The principle of operation of the generator, setup, operating characteristics, and schematic are covered in detail in the original post here The Wheelwork of Nature – Fractal “Fern” Discharges.

The feedback coil for the Armstrong oscillator now has variable windings, and is positioned offset from the secondary coil. The variable turn geometry of the feedback coil facilitates more accurate and optimal tuning of the generator based on the secondary coil used, and the lower or upper parallel mode being explored. Too much feedback to the generator will distort the drive waveform away from a clean sinusoidal, and too little feedback makes the oscillation unstable, and with a reduced gain in the generator. The optimal adjustment was to establish oscillation with the maximum number of turns on the feedback coil which produced a clean sinusoidal oscillation in the primary tank circuit. The number of turns varied for each secondary coil, and for the upper or lower parallel mode for each coil. With the correct number of turns set on the feedback coil, the generator match to the experiment was fine adjusted using the grid bias rheostat to produce maximum output from the secondary, with minimum average grid current.

Figures 2 below show a range of pictures of the experimental apparatus used in the video experiment, along with the measurement equipment, and some of the key construction details that vary from the original experiment.

Figures 3 below show some of the operation highlights during the experimental running, and the typical output from the measurement equipment, including generator driving frequency and waveform.

Again Tccad 2.0 was used for a rapid and approximate indication of the electrical and resonant characteristics of the secondary coils, the detailed results of which are shown below in figure 4. The wire selected for coil 1 and 2 is a good quality silicone coated multi-stranded conductor, the silicone coating being very good both thermally, and as an insulator to prevent breakouts and breakdown from the upper turns of the coil to the lower ones. For secondary coils 3, 4, and 5, a good quality polyester-polyamide coated magnet wire was used, with the final wound coil being further coated with high-temperature lacquer. The final lacquer coating is used to keep the windings in place, and add some additional breakdown insulation protection.

Small Signal AC Input Impedance Measurements

The small signal ac input impedance Z11 for each Tesla coil was measured directly using an SDR-Kits VNWA vector network analyser, as used on many experimental pages on this site. Figures 5 show the series-fed free resonant characteristics of the five Tesla secondary coils.

To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Fig 5.1. Shows the series fed input impedance Z11 for Tesla coil 1, design ƒSS = 3.49Mc. The measured fundamental series resonant mode ƒSS @ marker M1 = 3.41Mc, and with a 1m single wire extension at the bottom-end of the negative terminal of the VNWA. The parallel mode ƒSP @ M2 = 4.26Mc, and is characteristic of a standard Tesla coil design where the parallel mode is above the series mode when the secondary is on its own in a series-fed configuration. The characteristics of Tesla coil and TMT input impedance Z11 is covered in detail here Cylindrical Coil Input Impedance – TC and TMT Z11.  The large and well defined phase change at M1 shows the high quality factor Q of the coil, which mostly occurs when the geometry of the turns of the coil are not too tight, and have adequate spacing between them, in this case the distance between turns is ~ 1.35mm, the thickness of the silicone wire cladding, and the diameter of the wire is ~ 1.1mm. Geometry of Tesla coils and there design is covered in detail here Tesla Coil Geometry and Cylindrical Coil Design.

The coil is purely resistive at both the resonant modes ƒSS and ƒSP. At the series mode ƒSS reaches a minimum at ~ 70Ω, and a maximum of ~ 80kΩ at the parallel mode ƒSP. Both series and parallel modes are particularly useful depending on what type of generator is being used to excite the Tesla coil. A tuned linear amplifier, spark gap generator, or solid state inverter are best suited to driving the series mode, and a series feedback oscillator such as a class-C Armstrong oscillator is suited to drive at the parallel mode. With correct matching and tuning it is possible to couple significant power into the Tesla coil through either the series or parallel modes. The parallel mode allows for frequency adjustment dependent on how the tank circuit in the primary is setup, which is particularly useful for this experiment where a range of frequencies can be tuned dynamically during operation using a vacuum variable capacitor. If secondary feedback is arranged through a pick-up coil to the vacuum tube generator the parallel mode can be tracked dynamically with little additional tuning required during operation, other than at the band-edges where the grid-bias will need adjusting, and the feedback coil turns optimised.

At the series mode, frequency can also be adjusted by changing the wire-length at the top-end of the secondary coil. This is best affected using a telescopic aerial or other adjustable wire length, but is not so practical to adjust during operation without re-tuning the generator to the new frequency. Driven either at the series mode or the parallel mode, transmission mode conversion can be accomplished between the driving primary circuit, and the cavity of the secondary coil formed with the single-wire or transmission medium connected to the bottom-end of the secondary coil. In principle, power in the TEM transmission mode in the primary circuit, can be transferred and transformed to the LMD transmission mode in the cavity of the secondary coil. The cavity in principle can be made to extend over very large distances, presenting the possibility for power transfer at very low-loss over very large distances in the far-field, and many times the wavelength of excitation at the generator. A second tuned Tesla coil in the cavity of a TMT system transforms the LMD mode back to the TEM mode in the receiver primary. The transfer of power, which accompanies the transformation of transmission mode from the cavity in the secondary to the primary circuit of the receiver, can then be used to do work in the load. It is interesting to note that the frequency of the LMD mode in the cavity is not the same as the frequency of the TEM modes in the primary of the transmitter and receiver.

Fig 5.2. Here secondary coil 2 has series mode ƒSS = 2.03Mc, and parallel mode ƒSP = 2.52Mc. Compared to coil 1 this is more tightly wound, with reduced conductor spacing and more turns, and hence the Q has reduced significantly, as can be seen in the reduction of the magnitude of the phase swing at M1. Both coils 1 and 2 are on the same magnitude and phase scales, and the phase reduction for this coil is a factor of ~ 2. The longer wire length has also considerably increased the coil resistance at the series and parallel modes, RSS = 160Ω, and RSP = 122kΩ. The second odd harmonic at 3λ/4 is just visible at M3 @ 4.97Mc. This coil when combined with the primary in the video experiment shows the transition between the upper parallel mode and the fractal “fern” discharge, and the lower parallel mode which shows the “swords” discharge with an additional slight curvature. However, in the series-fed Z11 small signal impedance analysis there is nothing obvious that suggests some different electrical characteristic or feature that may be responsible for this dramatic transition from one discharge form to the other. It is worth considering at this point as to whether interaction between harmonics has any bearing on the discharge form. As the fundamental resonant frequency goes down through designed wire-length the harmonic frequencies become progressively closer which makes it more possible for energy to be transferred between the harmonics through the non-linear nature of the discharge.

Fig 5.3. Shows secondary coil 3 and the final coil used in the video experiment. Here the 2nd, 3rd, and 4th odd harmonics are very clearly defined. The phase scale has been expanded from 20°/div to 10°/div to show clearly the phase swing as it collapses with reducing Q of the coil, much reduced wire spacing, increased turns, and hence increased series coil resistance. Operation of this coil was still at the fundamental resonant modes rather than at harmonics, and when combined with the primary, (shown in figures 6), result in the parallel mode operating points used in the video. The series mode ƒSS = 1.10Mc with RSS ~ 370Ω @ M1, and the parallel mode ƒSP = 1.37Mc with RSS ~ 191kΩ @ M2. Harmonic frequencies extend at nλ/4 where n is an odd number, and with progressively reducing Q, and hence have a smaller and smaller impact as frequency increases. This coil clearly displayed the straight “swords” discharge at both the upper and lower parallel modes of operation, the slight curve was no-longer present and each discharge streamer projected straight outwards from the breakout point at the top-end of the coil. Streamers continued to be white and “hot” consistent with the generator drive which is at a maximum capped voltage defined by the two series transformers driven by the SCR, and current rich controlled by the “on” phase of the SCR power control.

Fig 5.4. and 5.5. Show the two lower frequency coils 4 and 5 that  were not demonstrated in the video experiment. In both Z11 measurements there are a very large number of harmonics, and the phase scale has been expanded again from 10°/div to 5°/div to reflect the collapsing Q of the coils, the rapidly rising series resistance from thinner gauge wire of many turns, and hence much longer wire lengths. Lower frequency Tesla coils like these tend to oscillate at a harmonic frequency when driven by a feedback oscillator using the parallel mode resonant frequency. In Fig. 5.4 it can be seen that the Q of the second odd harmonic at M3 is actually higher than the fundamental at M1. In this case the coil is more likely to stably oscillate at ƒSP2 the second harmonic parallel mode when driven using a series feedback oscillator. This will become clearer when we look at the parallel mode points when combined with the primary in figures 6.

Consequently many lower-frequency standard Tesla coils presented on the Internet tend to oscillate stably at the 2nd or 3rd harmonic when driven by a series feedback oscillator. To drive these two coils at their series fundamental resonant modes a fixed frequency linear oscillator or amplifier needs to be used where the frequency can be selected and fixed, and the generator is specifically matched at this fixed frequency, and then considerable power can be stably transferred to the secondary. This generator is more complicated than the series feedback tube oscillator, and required more setup, tuning, and matching to run at the equivalent power used in this experiment. For compatibility and simplicity with the previous Wheelwork of Nature experiment, I have kept the generator the same as before and avoided any additional complexity in the experiment, and its possible interpretation. I will look to make a video of these two low frequency coils driven by this form of fixed frequency generator in a subsequent experiment.

Figures 6 show the balanced parallel modes for each secondary coil when combined with the primary and tuned to balance using the primary circuit tank capacitor Cp. The primary tank capacitor is based on a KP1-4 10kV vacuum variable capacitor with range 20-1000pF. For the lower frequency secondary coils 3, 4, and 5, it was necessary to add a parallel static capacitor to the variable capacitor in order to increase the tank capacitive loading, and hence achieve balance of the upper and lower parallel modes.

To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Fig 6.1. Here secondary coil 1 has been added to the primary circuit shown in Fig. 1.5. The primary tank circuit is formed by the primary coil, the vacuum variable capacitor, and any additional fixed loading capacitance. When tuned correctly the parallel mode from the secondary coil occurs at the same frequency as the parallel mode from the primary coil. When the coils are coupled energy is exchanged backwards and forwards between the two parallel modes which causes “beat” frequencies, and a frequency splitting of the two parallel modes. The degree of splitting depends primarily on the magnetic coupling coefficient k, the Q of the two coils, and the geometry of the coils. The parallel mode from the primary results from the self-resonance of the primary coil, which is typically for the coil shown, around 30-50Mc for the fundamental series mode. The parallel mode of this self-resonance is at a much lower frequency than the series mode, and can be tuned down to even lower frequencies by addition of CP, the primary circuit tuning capacitance. The splitting of the two parallel modes from the primary and secondary results in the lower and upper parallel resonant modes of the Tesla coil, and can be driven and tuned directly when using a series feedback oscillator type generator. Tesla coil resonance modes are covered in much more detail here Cylindrical Coil Input Impedance – TC and TMT Z11.

When the parallel modes are tuned using CP to a point where the magnitude of their impedance is equal, and the phase angle of their impedance is zero, then the balanced mode is achieved. This condition balances the two parallel modes of the Tesla coil either side of the series fundamental mode, and has been found in some cases to be an optimum driving condition for a Tesla coil for certain different types of phenomena including, High Efficiency Transference of Electric Power in the close mid-field region, balanced TMT setup for LMD transmission experiments in Transference of Electric Power, and the equilibrium initial condition for experiments in the Displacement of Electric Power. This typical balanced mode for a Tesla coil is shown in this figure, where the fundamental series resonant mode is at M2 @ 3.45Mc, and the lower and upper parallel modes are at M1 @ 3.05Mc, and M3 @ 3.81Mc, and the primary tank capacitance Cwas set at 197pF to achieve this balanced point. At all of these three resonant modes the phase of the impedance is 0 degrees, showing the input impedance seen by the generator is entirely resistive, with no reactive components. The Tesla coil can be driven from any one of these three modes, and considerable power coupled intro the resonator from the generator.

Generator matching at any of these three modes requires an impedance transformation from the output impedance of the generator to the input of the Tesla coil, where at the three resonant modes this can be accomplished through a transformation of the resistive component only. For the series mode this usually involves using a tuning stage such as an high-power antenna tuner, specifically arranged balun or unun, or a fixed or variable RF transformer such as a “swing-link” tuning transformer. For example, to tune the series mode directly at M2, the input impedance Z11 is entirely resistive and RS = 28.5Ω. If a linear amplifier is being used as the generator with a usual output impedance of 50Ω, then an antenna tuner could be used to produce a good match with standing wave ratio (SWR) ~ 1. A 1:2 Balun (not 2:1) could also be used here since the ratio of the input resistance at M2 is close to 1:2. A balun is also useful here to convert the unbalanced coaxial feed of the generator to the balanced half-wave primary coil feed (λ/2). This considerably reduces radiated energy from the outer surface of the coax cable between the generator and Tesla coil, and also improves measurement accuracy when using inline RF power meters such as Bird Thruline analog 4410A, and digital 4391A.

For the parallel modes the input impedance is a much higher resistance e.g. at M1 = 3.05Mc, Rs ~ 10.7kΩ. This high impedance is very suitable for driving directly using the high plate impedance of a vacuum tube oscillator. When arranged properly at resonance so the match is purely resistive, or as close as can be accomplished, the match can be coarse adjusted through the number of feedback turns from a pickup coil placed close to the secondary coil. This type of positive feedback to the oscillator also means that the parallel mode frequency can be tracked by the oscillator, and hence a simple but highly effective tracking generator is arranged. By adjusting the position of the parallel modes, and which parallel mode is dominant, and hence the point of tracking, the generator can be auto-tuned over a wide frequency range either side of the series fundamental mode. Fine tuning of the match at any specific frequency is accomplished by adjusting the grid bias and/or the grid leakage at the grid storage circuit. If both of these are arranged with a rheostat very fine tuning and matching can be accomplished over a wide range of tracked frequencies. This particular generator arrangement has been very successfully used so far in the Wheelwork of Nature and Transference of Electric Power experimental series. It is relatively simple to arrange, is very tolerant to moderate mismatch conditions between the generator and the Tesla coil, and is highly flexible in its variable frequency range which can be adjusted directly during operation by adjustment of a vacuum variable capacitor.

When operated in the parallel mode using a feedback oscillator the tank capacitance CP was tuned either side of the 197pF necessary for the balanced point. At the balance point the oscillator output will not be stable as it jumps between the equal magnitude lower and upper parallel modes, and back again. For stable operation in the lower parallel mode CP is increased, and in the video experiment CP ~ 230pF was used to set the starting point of oscillation at 2.7Mc with the lower parallel mode impedance dominant. For stable operation in the upper parallel modes CP is reduced, and in the video experiment CP ~ 150pF was used to set the starting point of the oscillation at 3.2Mc with the upper parallel mode impedance dominant. The measurements taken in figures 6 are with the secondary coil connected to the experiment earth, that is, with the line earth of the apparatus only. When the experiment was further connected down to the RF earth for operation, the effective wire length increases slightly, and hence the fundamental series mode shifts down from ƒO = 3.45Mc to ƒO ~ 3.0Mc, the lower parallel mode ƒL ~ 2.8Mc, and the upper parallel mode ƒU ~ 3.1Mc which correspond with the operating frequencies presented during in the video experiment.

Fig 6.2. Here Tesla coil 2 has been balanced in the same way by increasing the primary tank capacitance to CP ~ 529pF, ƒO @ M2 = 2.06Mc, ƒL @ M1 = 1.85Mc, and ƒU @ M3 = 2.31Mc. The resistance of the two parallel modes have decreased significantly, mainly due to the additional capacitive loading in the primary, and also slightly from the lower frequency. The series mode resistance has also dropped from 28.5Ω @ 3.45Mc to 20.0Ω @ 2.06Mc. In this scan the series fundamental mode of the primary coil can just be seen at the very top-end of the scan at M4 = 4.98Mc. This also shows the wide frequency gap between the series mode of the primary coil self-resonance and the parallel mode, which is here balanced with the parallel mode of the secondary coil. As the primary tank capacitance is increased this series mode self-resonance of the primary coil moves lower in frequency, and can start to overlap with harmonic frequencies from the secondary coil. In this case a complex resonance is setup, and energy from the generator distributes over a number of different frequencies, producing a non-sinusoidal generator oscillation, and reduced power in the intended driven mode of the Tesla coil, (one of the three fundamental modes series and parallel). This distribution of energy across harmonic modes can produce unusual phenomena in the characteristics of the Tesla coil, and will be covered in more detail in a subsequent experiment.

Fig 6.3. Shows directly an example discussed previously where the self-resonance of the primary, tuned down in frequency to the balance point using increased CP, has overlapped and hence interacted with the second odd harmonic of Tesla coil 3. From Fig. 5.3. we can see that the second odd harmonic has a fundamental frequency ƒSS2 @ M3 = 2.69Mc. The two interacting resonant modes from the primary and the secondary take place centred around M4 @ 2.72Mc, where a number of phase changes can be seen as two series fundamental modes move past each other. As these modes are coupled between the two coils through the magnetic coupling coefficient k2, they interact and again cause “beat” frequencies and a splitting of the two series modes for the duration of their overlap interaction. In this condition when the Tesla coil is pumped by the generator at any of the fundamental series and parallel modes, M1 – M3, some of the coupled power will also interact at the second harmonic mode overlapping with the primary fundamental mode. A complex resonance condition is setup, and the generator drive oscillation will become a complex waveform with multiple interacting frequencies. Less power will be coupled through the fundamental modes, as some will be lost to the “beating” second harmonic mode.

The loading primary capacitance in this case necessary to balance the parallel modes CP = 1634pF, was made by adding 1000pF fixed capacitor in parallel with the KP1-4 vacuum variable capacitor set at ~ 634pF. In balanced arrangement ƒO @ M2 = 1.12Mc, ƒL @ M1 = 1.01Mc, and ƒU @ M3 = 1.28Mc. It should also be noted that the increased capacitive loading of the primary is now reducing the Q significantly of the Tesla coil. In this case the coil can still be driven at the parallel modes by a feedback oscillator as shown in the video experiment, but the operation band is narrower, and performance diminishes more quickly as you tune away from the fundamental series mode at 1.12Mc.

Fig 6.4. and 6.5. for the lower frequency Tesla coils 3 and 4 show exactly the same characteristics and trends as for coil 3. Here the Q can be seen to be diminishing rapidly and for these two coils is it is exceedingly difficult to get them to oscillate at their fundamental modes when loaded so heavily with primary capacitance. For coil 4 Cp ~ 4951pF for balance, and for coil 5 CP ~ 11676pF. Coil 4 and 5 could only just be driven at their upper parallel mode around 600kc and 890kc respectively using the generator as setup for this experiment, although the discharge output was very small for large amount of power provided by the generator, (up to 3kW in testing for a discharge of no more than several centimetres). The discharge form in both cases was straight “swords” in higher density than the higher frequency coils.

If the capacitive loading was reduced in the primary to move oscillation away from the fundamental modes only, then both coils 4 and 5 would adequately oscillate around ~ 1.0-1.5 Mc, where the Q of the Tesla coil was higher, and there was adequate feedback from the secondary coil to the generator. From Figs. 5.4 and 5.5 this corresponds to the 2nd harmonic for coil 4, and the 3rd harmonic for coil 5. For fundamental operation of these two coils at maximum power and performance, a fixed frequency linear amplifier or oscillator should be used, tuned and matched to the fundamental series resonant frequencies ƒO @ M2 ~ 650kc for coil 4, and ƒO @ M2 ~ 420kc for coil 5. I will look to demonstrate the characteristics of these two coils using the different generator in a subsequent video, which will show and confirm that the discharge form for both of these generators is also straight “swords”.

Fractal “Fern” vs Straight “Sword” Discharges

Figures 7 and 8 show a selection of discharge images taken from the video experiment, and in order to illustrate the differences between the fractal “fern” shown in figures 7, and the “swords” discharge shown in figures 8. The images are selected from a number of different operating points and coils and comparable operating power. For a detailed consideration of the fractal “fern” discharge see the discussion in The Wheelwork of Nature – Fractal “Fern” Discharges.

It can be clearly seen from both these figures that the general characteristics of the main streamers appear almost identical for “ferns” and “swords”. The structural detail along the length of the streamers has in common a “hedge” of corona, micro-filaments and strands emanating orthogonally along its length, and distinct places where sub-tendrils emerge. In the “swords” discharges there are very few emerging sub-tendrils from the primary, although there is evidence that sub-tendrils are starting to emerge they do not progress very far. In the “fern” discharge there are well defined secondary and even tertiary tendrils that branch at specific points from the main streamer. This is distinctly different for the “swords” where the main streamers all appear to extend straight outwards from the breakout point, with no major secondary or tertiary tendrils.

Of course the most distinct difference between the “ferns” and the “swords” is the change in curvature of all streamers and tendrils. The “fern” takes on the appearance of the beginning of a spiral extending through an invisible trajectory to an invisible inner focus point. It has been shown in the previous post of this series that the spiral may have golden-ratio proportions, and it has been conjectured that the focus of the spiral could be a source or sink point for the discharge. In contrast the “sword” discharge extends straight out from the breakout point without curvature at the outer end for the lowest frequency discharges from coil 3, and as far as 30cm long when operated around 2kW of generator input power, and in the centre of the parallel mode band. In the transition between “ferns” and “swords” in coil 2 some curvature can still be observed as the “fern” straightens out to a “sword”, which can be seen in more detail in the next figures.

Figures 9 below show a set of discharge images of the sequence of the change of discharge form from coil 1 upper parallel mode, through the intermediate modes, and to coil 3 lower parallel mode in order of descending frequency. Each image has been selected from the video experiment as a general representation of the form of the discharge at the centre of the respective mode, and where possible with comparable generator input power.

To view the images in a new window whilst reading the explanations click on the figure numbers below.

Fig 9.1. The fractal “fern” from the upper parallel mode of coil 1 at 2.97Mc  and 1.6kW shows the tightest and most dense form of the “fern” discharge. There are many primary streamers, some with secondary tendrils. The spiral curve at the tendril-ends is well developed, and many smaller orthogonal tendrils are present. Here a primary streamer in the centre is in the process of extinguishing which starts at the breakout point and travels outwards along the tendril as the energy of the tendril is exhausted to its outer limit. It is this observation in the previous post in the series that gave rise to conjecture that the focus point of the invisible spiral may act as sink for the streamer. Typically this highest frequency “fern” in the sequence is characterised by many well formed fractal tendrils that are more densely packed together, and the overall discharge form takes on the appearance of a “ball” with a fractal tree inside.

Fig 9.2. The classic fractal “fern” discharge at the centre of the lower parallel mode of coil 1 at 2.71Mc and 1.8kW, which generally shows a small number of well defined streamers, often with secondary and even tertiary tendrils emanating orthogonally from the primary. At this frequency the tendrils are small spread-out, less dense, and have lost that “ball” type of outer shell appearance seen in the previous upper parallel mode. Micro-filaments and the corona like bluish-hedge are very prevalent at this frequency, and also discharges have been seen to fit well into a number of different form categories, and also to display temporal based repetitive sequences, in the form of a “dance”. Primary streamers and sub-tendrils at this frequency are almost all entirely curved with an invisible spiral at the end, although there are the occasional straighter streamers with gradual curve.

Fig 9.3. Still the classic fractal “fern” discharge at the upper parallel mode of coil 2 at 2.27Mc and 2.0kW. At this upper parallel mode there appears no real difference between the discharges of coil 1 and coil 2, and no measured or experimented evidence that the form of the discharge is about to change so dramatically at the lower parallel mode of the same coil.

Fig 9.4. Now at the lower parallel mode of coil 2 at 1.71Mc and 2.1kW, we see the distinct transition from fractal “fern” to straight “swords”, or in this case straighter “swords”. At this transition frequency many of the swords still have a distinct curvature across their length from the breakout point. The “sword” type discharge has become more basic along its length, without secondary or tertiary tendrils, but retaining the micro-filament and bluish-hedge along the majority of its distance from the breakout point. Here the main central streamer is just starting to extinguish from the breakout point in what appears to be exactly the same mechanism as the fractal “fern” streamer. It is also noticeable that the straight “sword” is characterised by a very sharp single tip, whereas the fractal “fern” most often has a “feathered” final type with the multiple small ending points, or the possibility for splitting of the tip.

Fig 9.5. At the upper parallel mode of coil 3 at 1.35Mc and 2.2kW the “swords” have fully straightened along their length, still with a sharp single tip, and otherwise very similar characteristics to the lower parallel mode of coil 2 in the previous figure.

Fig 9.6. And finally at the lowest frequency in this reported experiment, at the very top-end of the lower parallel mode of coil 3 at 0.97Mc and 1.8kW, the primary streamers have become narrower and more sharp, with very little micro-filament and bluish-hedge detail along their length. These types of streamers now look very typical for a VTTC operated at around 1Mc with a tightly wound, high aspect ratio coil, with many densely packed turns of magnet wire. The streamers have lost almost all of the detailed features of the fractal “fern”. In fact, it would not be evident from this result that at higher frequency a completely different form of discharge is available from exactly the same apparatus, other than the winding of the secondary coil, and hence its designed wire-length and fundamental series mode resonant frequency.

Vibration, Quality, and Frequency

In this follow-up experiment we have looked to investigate in more detail what causes the fractal “fern” discharge and in particular how the discharge form changes with frequency. In the previous experiment in the series quite a few different variations were tested in order to discover the dependence on key system parameters such as the generator drive waveform, tuning and loading of both the primary and secondary coils, feedback and operating point of the oscillator generator, and even a different generator using wholly different vacuum tubes. These variations caused small changes in the operation range of the apparatus, but did not make an observed difference to the fundamental form of the discharge, in other words, the discharge was still fractal “fern” in nature.

In this experiment it is very clearly shown that frequency has a most significant impact on the discharge form. As many other variables in the experimental apparatus have been kept the same in order to not introduce unknown variations into the experimental method and results, it can be stated that frequency is so-far the most prominent parameter and variable with the most impact on the discharge, and particularly as a single Tesla coil, coil 2, was able to demonstrate both the fractal “fern”, and the “swords” discharge form, and some of the transition between these two forms. Maybe this implies that there is a significant difference when driving in the lower and upper parallel modes, but this appears not to be the case given that coils 1 and 3 showed little variation of discharge form between their lower and upper parallel modes, coil 1 with fractal “fern” in both, and coil 2 with “swords” in both.

We also see that the generator drive waveform also appears not to make a difference between fractal “fern” and “swords”, as in all driven modes the apparatus was carefully tuned through pick-up coil feedback, and grid bias and leakage, to make sure that the oscillating waveform in each of the secondary coils was a clean sinusoidal, without harmonics, and with minimal distortion due to clipping, saturation, and reflected power. Furthermore the ground system for the apparatus was consistent amongst all operation, and was also checked using the VNWA for any line resonance or harmonic characteristics in and around the operating frequency range. None were found, and there was no evidence of waveform distortion or non-linearity from the generator during the experimental operation. In fact the output of the oscillator generator was particularly clean all the way up to 3kW of utilised input power.

So all this care and attention to the experimental apparatus, method, measurement, and analysis, tends to indicate to me that the form of the discharge is fundamentally based on the inter-action between the dielectric and magnetic fields of induction in and around the experimental apparatus, and to the electrical and physical response or re-action of the common medium surrounding the Tesla coil, including the response of the materials and properties of the components used to make the Tesla coil. For example, the discharge requires a medium in order to form, in this case the air surrounding the coil. During the discharge breakdown of the medium forms a highly charged plasma “gas” around the breakout point. The characteristics and behaviour of this electrical plasma are then determined by the specific relationship between the dielectric and magnetic fields of induction surrounding the Tesla coil, and the form and nature of this discharge simply “follows” the relationship between the two induction fields, or said another way, “makes” the relationship between the two induction fields visible.

If we follow on from this conjecture, and bearing in mind the oscillator generator is a linear energetic excitation of the Tesla coil, rather than a disruptive non-linear impulse excitation, and the formation of a highly charged plasma “gas”at the breakout is a non-linear process, then we have the basis to further conjecture that the nature of the observed discharges are following a well defined linear sequence. It does not appear from all the measurements taken that the discharges appear like “random” trajectories through the common medium, as appears with natural lightning discharges, or from those generated from a spark-gap Tesla coil (SGTC), or well tuned dual resonance solid-state Tesla Coil (DRSSTC). The fractal “fern” has demonstrated spatial and temporal structure and geometry, ordered temporal sequence, and containing boundaries to the extent and extinction of the discharge. From this I conjecture that the fractal “fern” results from a more deeply rooted underlying vibration in the wheelwork of nature, a vibration that demonstrates defined qualities, or said another way a vibration in life composed of a distinct set of properties and principles.

And this is a most important distinction between vibration and frequency, where vibration is like a “tensor” combination of different fundamental qualities of life brought together or contained with a specific bounding or guiding purpose, whereas frequency is a “scalar” property which describes the rate of change of the vibration. So the vibration is the set of qualities that are being exposed by the discharge, and the frequency describes one property of this vibration. As the frequency changes so the quality and meaning of the vibration changes from one form to another. The vibration in turn determines or “guides” the relationship between the dielectric and magnetic fields of induction, and through the nature and form of the discharge we can visually observe the characteristics of the underlying vibration, as expressed through the electrical framework of the induction fields, and responded to by the physical action of the charged plasma “gas” created from the air.

If we accept this conjecture as a working hypothesis then it follows on that the detailed nature of the fractal “fern”, and for that matter the “swords” discharge, demonstrate details of all the underlying principles and properties that compose the collective vibration. So the trajectory of the primary streamers, the position and nature of secondary and tertiary tendrils, the asymmetry or symmetry of the discharge, the orthogonal micro-filaments, the bluish-hedge corona, the spiral or straight nature, and bifurcated or pointed end-tips etc. all represent interactive qualities within the expression of this particular vibration. Our job in uncovering the wheelwork of nature is to understand the purpose and meaning of the qualities at work, how they interact with each other, and how they form together as specific and different vibrations that express the diversity through the response of the common medium. This leads us squarely to the multidisciplinary approach to my research that is covered in much more detail on this website in the section on The Foundation for Toltec Research.

So, in summary to this discussion of the experiment in this post, it is conjectured that the scalar quantity frequency shows itself as a most important property of the guiding vibration determining the relationship between the dielectric and magnetic fields of induction, which is expressed through the electrical discharge form in the common medium surrounding a Tesla coil. When frequency is varied the nature of the vibration changes, and hence the form of the discharge changes to reflect a change in the underlying qualities of the vibration. The challenge stands to determine what the meaning of this is, and what specifically are the qualities that form the vibration being expressed, and the dependence on the inter-action with this vibration and the surrounding medium. All these areas needing considerable further consideration, investigation, and experimentation.

Summary Conclusions and Next Steps

Three Tesla coils have been used in this experiment to demonstrate that the fractal “fern” discharge changes to a “swords” discharge when the apparatus is kept constant, but the frequency of the secondary coil is varied from 3.4Mc down to 0.9Mc. The dramatic and spectacular change in the discharge form, combined with seemingly coherent spatial and temporal properties of the discharge, suggest as yet unexplored and undiscovered underlying principles and mechanisms within science, and the Wheelwork of nature. The challenge posed by the results of this experiment is to design further experiments to reveal more of the principles and mechanisms of the vibrations being expressed, and also to explore additional variations to the basic experiment that may provide more clues and evidence to confirm or refute the conjectures made so far. Next step experimental steps include the following:

1. Different generators should be tested with the same Tesla coil apparatus, including a spark gap generator, and linear amplifier generator to drive all five coils at the series fundamental mode.

2. A driven coil arrangement for the secondary coil only, with no primary coil, and hence simplifying the experimental apparatus and resonant interaction between the primary and secondary.

3. The introduction of non-linear impulse excitation to the Tesla coil to compare the effect of the linear and non-linear excitation waveforms, and their impact on the type of discharge.

4. The change of discharge in different surrounding gaseous mediums other than air. This might include discharge in a gas-filled vessels, plasma-like conduction experiments, and displacement of electric power experiments using high voltage impulse discharge.

Click here to continue to the next part, ESTC 2022 – Vector Network Analysis & Golden-Ratio/Fractal-Fern Plasma Discharges.


1. A & P Electronic Media, AMInnovations by Adrian Marsh, 2019,  EMediaPress

2. Dollard, E. and Energetic Forum Members, Energetic Forum, 2008 onwards.


 

Transference of Electric Power – Single Wire vs Telluric

In this new experiment on transference of electric power a comparison is made between power transfer through a single wire and through a telluric transmission medium, using a cylindrical Tesla magnifying transformer (TMT) apparatus. The TMT apparatus and linear generator is the same used in the High-Efficiency Transference of Electric Power series  both over 1.5m and 11m, and these new experiments are a continuation on those previously reported. This experiment is also the first in a new series on telluric transmission of electric power, and whilst I have experimented with telluric transmission over the years, none of this fascinating area of Tesla research has yet been reported here on the website. One of the pictures in the main slider at the head of this website shown here, shows telluric reception experiments made in 2017 at the upper parallel mode of a nominally 2Mc, 160m amateur band, flat coil. In the experiment reported in this post, the TMT transmitter and receiver are housed in different buildings of the lab, and can be connected by a 30m single wire, or a telluric channel ~18m point-to-point between the two ground systems, and 26m in total length including the cables. There is no special consideration of the ground/earth/soil between the two buildings, although the transmitter ground system used is specifically designed and constructed to provide a low impedance connection to ground.

Wireless transmission of power at a global level appears to have been one of Tesla’s greatest vision’s and endeavour’s, and one that he appears to have invested so much of his time, effort, and money. From early experiments in his New York laboratory, to larger scale experiments at Colorado Springs, to the grand-scale transmitter at Wardenclyffe, which unfortunately does not seem to have been operated in earnest before being dismantled. Tesla communicated this work mainly through his patents[1,2], demonstrations and presentations[3,4], and personal research notes[5]. In more recent years his life and work have been discussed and considered in a lot of detail, and there are many different perspectives online regarding all aspects of his endeavours, from whether there was/is any basis for this TMT system to work at all, all the way through to detailed analysis of how such a system was constructed, how it was intended to be operated, and the kind of results that could be accomplished in power distribution through this method. What is much more rare is solid experimental evidence, measurement, and subsequent consideration and analysis of what can be experimentally accomplished in transferring power between a transmitter and receiver in a TMT arrangement through the earth. This specifically includes what power levels can be transferred over what distance, at what frequencies, with what level of losses, and through what transmission principles and modes, and in addition, what the impact of this would be for the surrounding environment and life in general.

What follows are my own considerations and perspectives on Tesla’s Wireless Power, and what I feel are some of the most important considerations for these types of experiments. I will over a series of posts be demonstrating aspects of these principles, and looking at the type of results that I have been able to accomplish so far in this field. For me, Tesla’s “wireless” power as a description of the field is somewhat misleading, as in my perspective it never really was “wire-less”, in other words it never involved no “wires” between the transmitter (TX) and receiver (RX). By this I mean that the TMT apparatus, to transfer even the tiniest amounts of power between TX and RX, requires a single transmission medium of lower impedance than the pervasive surrounding medium, and connected from the TX secondary coil lower-end, to the RX secondary coil lower-end. So if we assume that the pervasive surrounding medium is air, then the single transmission medium of lower impedance might include, for example: a single metallic wire, a telluric channel through the ground, or even a gas discharge tube that has been ignited by the potential gradient across the Tesla coil secondary. If this single transmission medium is not present then only minute levels of power can be transferred between the TX and RX, consistent with transverse electromagnetic propagation from a radio transmitter to a radio receiver.

I could conjecture that Tesla may have seen his TMT approach to power distribution as distinctly “wire-less” when compared to other electrical systems of the time, like Edison’s DC power distribution, that required two conductors to make an electric circuit between the generator and load, and hence the normal losses that occur in a closed loop electrical circuit. In simple comparison, Tesla’s system appears as an open loop electrical circuit relying on the potential gradient of the “cavity” established across the secondary coil of the TX, the transmission medium, and the secondary coil of the RX. In this cavity it has been suggested that a different mode of transmission can be established, the longitudinal magneto-dielectric (LMD) mode, which is again distinctly different from the transverse electromagnetic (TEM) mode, and in principle can lead to very high-efficiency of power transfer, over very large distances, and with very low losses. These modes have been proposed and explored in detail by electrical researchers such as Eric Dollard[6-10] , and other aspects of wire-less power by researchers including Tucker et al.[11] and Leyh et al.[12], and also in my own experiments in the Transference of Electric Power series on this website.

Another important aspect that has been widely discussed is the requirement for the ground systems used at both the TX and RX in a TMT system, to present the very lowest impedance possible, or resistance at resonance, to connection of the TX and RX coil to the telluric channel. This would appear to be common sense, at least for the TEM transmission mode, where the lowest losses in the system will occur when the impedance of the ground connection at the TX and RX are at their lowest, combined with the lowest impedance of the single transmission medium between the two. However, this is not necessarily the case for the LMD mode, where in my own experiments and particularly the first in the sequence on High-Efficiency Transference of Electric Power, it is demonstrated that the efficiency of the power transfer increases as the impedance of the single-wire medium increases. In particular it was demonstrated that more than 500W of power can be transferred through a single wire no thicker than a human hair, a 40AWG (0.08mm or 80 microns) nickel plated copper wire, where the power transfer efficiency could be measured up to 100% according to the limits of experimental accuracy of the measurement equipment.

It was suggested in this previous experiment that … “Power transfer of this order through such a thin wire is possible as the dielectric and magnetic fields of induction are contained or guided around the single wire. Removal of the single wire from the receiver end prevents any power transfer to the receiver, which shows that when driven by a linear sinusoidal generator, a lower impedance transmission medium, (in this case the single wire), is needed to guide the induction fields between the transmitter and receiver coils.” So in principle it could be conjectured from this unusual result with a very fine single wire, that provided the correct LMD mode is arranged in the cavity of the TMT system, the lower impedance of the ground system may not be as important as previously suggested. Certainly for the TEM mode in the transmission medium large losses will occur from higher impedance connections and the single wire medium itself, as well as radiative losses along the length of the single wire, and reflections from impedance mismatches and transitions across the cavity. From my results I conjecture that the combination of the TEM mode in the TX primary, LMD mode in the cavity formed by the TX secondary, transmission medium, and RX secondary, and the TEM mode in the RX primary, leads to the highest efficiency in the transference of electric power, and is discussed in detail in High-Efficiency Transference of Electric Power – 11m Single Wire.

The LMD mode also removes the requirement for every part of the TMT system to be in principle at the same resonant frequency. It seems to be widely thought that the highest efficiency of transmission of power takes place in a TMT system when all the sections are arranged to resonate at the same frequency, hence forming one continuous minimal impedance coupled resonator system. Whilst again this would most likely be the case for the TEM mode, from my own measurements it is not so for the conjectured LMD mode. I have measured that at highest efficiency of power transfer the LMD mode in the single-wire is not the same frequency as that measured in the primary of the TX or the RX. Furthermore, there is spatial coherence of the LMD mode but not temporal in the cavity. In the TEM mode there is temporal coherence across the cavity but not spatial, measured, presented and considered in detail in Transference of Electric Power – Part 1. These experiments and their results, suggest that there are significant differences between the TEM and LMD modes, and how a TMT system performs when it is arranged to operate in one mode or the other, or in a combination of both modes, which I conjecture and have in-part confirmed through measurement, is actually the optimum arrangement for the highest efficiency of power transfer.

This experimental post consists of two video experiments one based on a single-wire 30m TMT system, and the other with the same TMT system connected by a telluric channel. Telluric is often used as a description of the transmission medium in Tesla research when the ground/earth/planet is used to form the “single wire” and hence the cavity between the TX and RX. In this case the impedance of the Telluric channel is much higher than that of the single metallic wire, and hence we make a comparison as to the likely power that can be transferred through the channel, what modes of transmission are involved in the system, and what the magnitude and mechanisms of the losses are involved in the channel. The generator used in both experiments is the same linear amplifier generator featured in the High-Efficiency Transference of Electric Power series, and is explained in detail in those posts, and is used to drive the TMT system at the fundamental series resonant mode. In addition to measuring power transfer in both mediums, the small signal impedance characteristics of the TMT system are measured, and then tuning and matching the generator to the apparatus to ensure maximum power transfer to the experiment with the minimum losses.

The first video experiment of a cylindrical TMT system with a 30m single wire demonstrates and includes aspects of the following:

1. A Cylindrical TMT experimental apparatus using a 30m single wire transmission medium between the transmitter (TX) and receiver (RX) coils.

2. Setup, matching and tuning, and operation of a 1kW linear amplifier generator, adjusted to drive the TMT experiment at the available series resonant modes, and further adjustment during operation to maximise the power transfer efficiency, and minimise reflected power.

3. Small signal ac input impedance characteristics Z11 from the perspective of the generator, and showing tuning of both the series and parallel resonant modes to establish optimum experimental starting conditions.

4. At 1.920Mc using a balun feed to the transmitter the maximum power transfer efficiency was measured at ~ 34%.

5. At 1.890Mc without using a balun feed to the transmitter the maximum power transfer efficiency was measured at ~ 40%. This frequency and drive method produced the highest efficiency observed during the experiment.

6. The optimum power transfer was accomplished with the maximum number of four primary coil turns, and balanced parallel modes, at both the TX and RX coil.

7. Extension of the single wire from 30m to 40m, close to the quarter wavelength of the generator drive frequency, did not change the maximum measured power transfer efficiency of ~ 40%.

8. It is discussed and conjectured that the TEM transmission mode is dominant in the experimental setup, and as a result large losses occur through radiation from the single wire.

9. It is conjectured that the LMD transmission mode was not adequately established in the single wire over 30m or 40m, and hence the much lower power transfer efficiency than expected from previous experiments with 1.5m and 11m single wires. In previous experiments with an 11m single wire transfer efficiencies up to 96% were measured, and it was conjectured that the LMD mode was adequately established as the dominant transmission mode.

Video Viewing Note: The video control bar has a “Settings” cog icon where you can select video quality, which by default is set to “Auto”. For clear viewing and reading of the VNWA software characteristics and text on the computer screen, “1080p” video quality is recommended, and may need to be selected manually from the settings icon once playback has started.

The second video experiment of a cylindrical TMT system with a telluric channel demonstrates and includes aspects of the following:

1. A Cylindrical TMT experimental apparatus using an 18m Telluric transmission medium between the transmitter (TX) and receiver (RX) coils.

2. Setup, matching and tuning, and operation of a 1kW linear amplifier generator, adjusted to drive the TMT experiment at the available series resonant modes, and further adjustment during operation to maximise the power transfer efficiency, and minimise reflected power.

3. A custom ground system, using copper water pipes driven into the ground, and consisting of a main RF ground and a reference test ground.

4. Small signal ac input impedance characteristics Z11 from the perspective of both the TX and RX, and showing tuning of both the series and parallel resonant modes to establish optimum experimental starting conditions.

5. Large signal tuning using a small breakout flair at the top of the telescopic tuning aerial attached to the top-end of the TX secondary coil.

6. Signal reception tuning, using a Sony ICF-2001D radio scanner, to calibrate the proportion of signal transmitted through the radio-wave and the telluric-wave from the transmitter to the receiver.

7. At 1.860Mc 10W of input power at the TX resulted in ~0.55mW via the radio-wave, and ~0.7mW via the telluric-wave, and a total of ~1.25mW at the RX coil, into a HP435B power meter with an 8481H 3W thermocouple power sensor.

8. At 1.860Mc 500W of input power at the TX resulted in a total of ~80mW at the receiver through the radio-wave and telluric-wave combined.

9. It is discussed and conjectured that almost all of the transmitter power is absorbed into the earth around the ground system, and radiated from the secondary coil in the TEM transmission mode. This diffuse absorption and radiation around the transmitter system results in very little power incident on the RX system, and hence at 1.860Mc in the 160m amateur band, radio communication appears possible through the telluric system, but significant transference of electric power does not appear possible at this frequency.

Video Viewing Note: Again “1080p” video quality is recommended, and may need to be selected manually from the settings icon once playback has started.

Figure 2 below shows the schematic for the experimental apparatus used in the video experiments. The high-resolution version can be viewed by clicking here.

Experimental Apparatus and Operation

The schematic and principle of operation for the experimental apparatus used in the video experiments is a variation to that used in the High-Efficiency Transference of Electric Power series. Much of the equipment used, and a detailed explanation of the linear amplifier generator are covered in that series of posts. The power measurement meters have been changed from the Bird 4410A analogue thruline power meters, and replaced with 4391A digital readout thruline power analysers. The digital readout of the Bird meters makes them easier to read both during the experiment, and on the video. The 4391A power meters were both calibrated using the same inline method previously presented, at 500W input power for direct comparison on a single range, and with a limit of experimental error of <0.5%. User uncertainty and errors in reading the analogue dial during the experiment is further reduced through using the digital readout. The other significant measurement additions are for the telluric transmission experiments where the received powers are much smaller and hence different instruments have been used. Radio signal strength is measured using an Sony ICF-2001D radio scanner, which has been adapted to allow for a direct BNC input for external antenna connection, as well as the integral telescopic aerial mode. Direct received power levels are measured using a Hewlett Packard HP 435B power meter with a HP 8481H 3W thermocouple power sensor.

As demonstrated in the video the 30m single wire transmission experiment is initially setup using the VNWA and these results are discussed below. This provided a tuned starting point for the complete TMT system, where the TX and RX coils are arranged to resonate at the same frequency. The fundamental series resonant mode was initially set at 1.92Mc, but then subsequently empirically adjusted to 1.89Mc for slightly increased transfer efficiency across the single wire. The parallel modes of both the TX and RX coils were balanced, using their primary coil tuning capacitors, to equal magnitude of impedance, before connecting the 500W load to the RX coil output. Care was taken to keep the operating frequency of the TMT system within the 160m amateur radio band, and also where the lab is in a remote setting to minimise any operation interference on adjacent radio bands. With the initial conditions set the power was increased gradually from 10W up to over 500W, whilst minimising any reflected power back to the linear amplifier by adjustment of the Palstar antenna tuner. In this way power could be passed to the transmitter across the 30m single wire and into the receiver to power the load.

It is important to note from the generator tuning and operation in part 1 of the video experiment the differences that arise in power measurement at the linear amplifier output, (as measured by the MFJ-998), and that measured at the input to the TX coil by the Bird 4391A. The 4391A measures forward and reflected power right at the input to the primary coil which depends on  the match between the antenna tuner output impedance and the TX input impedance. At resonance the input impedance of the TX coil is predominantly resistive and the SWR as measured by the 4391A varied in the range 1.5-2.7 dependent on the fine tuning of the antenna tuner. The power measured at the output of the Kenwood linear amplifier by the MFJ-998 is now on the input side of the Palstar antenna tuner, where the tuner is transforming the impedance of the TX coil to be as close to 50Ω as possible, minimising reflected power back to the linear amplifier, and allowing maximum dynamic range and output power utilisation from the linear amplifier. So when the MFJ-998 SWR is minimised in the experiment as close to 1.0 as possible, the MFJ-998 is used to measure the power supplied from the linear amplifier into 50Ω impedance, and the 4391A is user to measure forward power into the impedance presented by the TMT system at its primary coil input at the TX. These two meters will then read a different power when at the minimised SWR of the linear amplifier, and will read more closely the same as the SWR is detuned at the antenna tuner to correspond to the TMT input impedance.

For consistency in experimental measurement of the input power and output power of the TMT system the forward power measured both by the 4391A at the TX, and the 4391A at the RX was used to assess the power transference efficiency across the TMT system. This was then compared at two tune conditions of the antenna tuner, firstly when minimising the SWR presented to the linear amplifier which leads to different power readings on the MFJ-998 and TX 4391A, but minimal reflected power at the linear amplifier output. The second with detuned SWR between ~ 1.5-1.9 presented to the linear amplifier which leads to close match between the power readings on the MFJ-998 and the TX 4391A, but with slightly reduced efficiency and increased reflection at the output of the linear amplifier. As demonstrated in part 1 of the video, the experiment was initially operated using a 1:1 current balun at the output of the 4391A in order to properly convert the output from the unbalanced output of the generator, to the balanced input condition of the primary coil. However this appeared to reduce power transfer efficiency by up to 5% and was subsequently removed from the experiment when it was empirically retuned to 1.89Mc.

For the telluric measurements where the RX coil is not visible to the TX VNWA measurement the initial tuned conditions were set to 1.87Mc using the VNWA small-signal fundamental series mode of the TX coil connected to the telluric ground system. This was slightly empirically adjusted to 1.86Mc when tuning using the large-signal generator drive, and corresponded with the maximum neon brightness at the top-end of the TX secondary coil. A small breakout flare was generated at high TX input power > 700W which also was maximised around 1.86Mc. Care needs to be taken only to use this as a large-signal tuning check, as any breakout at the top-end of the secondary coil will reduce the top-end impedance of the coil to the surrounding-environment effectively increasing the quarter wave length of the coil, and hence reducing the series resonant frequency of the TX coil. By both empirical tuning methods 1.86Mc was determined to be the optimal large-signal generator driving frequency to the telluric connected TX coil with 39cm defined telescopic aerial extension. This tuned telluric experimental frequency keeps all the experiments in the 160m amateur band with a very high-Q TX and RX coil, and hence very tightly contained transmission bandwidth using only CW and morse-code for radio call-sign identification.

Another key measurement in the telluric experiment which needs some consideration is the process of measuring the radio-wave of a radio transmission. For all radio transmission, and as transmitters are almost always grounded down to earth, there major component of the transmission, that is the propagating TEM wave from the radio transmitter antenna to the receiver antenna. In relation to the telluric part of this experiment, we cannot assume that all the power transferred from the TX to the RX coil is via the telluric channel through the ground, as there will also be a radio-wave component at the receiver. We also cannot simply remove the bottom-end ground connection of the RX coil to measure the this radio-wave component, as this will change the wire-length of the secondary cavity, and hence change its fundamental series resonant frequency, and any connected receiver which is tuned to the transmitter frequency will erroneously show no received signal, simply because the RX coil is not correctly tuned to the transmit frequency.

To accomplish the radio-wave part of the experiment, and as demonstrated in part 2 of the video experiment, the telluric ground connection is removed from the RX coil, and is replaced with a single wire 10m in length which is NOT connected into the ground or to any other grounded end-point. The telescopic aerial at the top-end of the RX coil is now fine adjusted so that the series mode resonant frequency of the RX coil matches the transmit frequency. This is accomplished by maximising the received signal at the receiver at the correct TX frequency, and then cross checked by VNWA measurement to confirm correct tuning of the RX coil. In this way the RX coil is now tuned to the correct frequency for receiving the transmitted signal, but is also not connected in any way to the ground. The signal strength now received on the radio receiver, or power meter, is a result of the radio-wave contribution only, and is less than the combined radio-wave and telluric-wave, as can be seen in the video experiment. The proportion of radio to telluric wave can also give a good indication as to the dominant transmission mode involved in the transference of electric power between TX and RX coil. Equal radio and telluric components tend towards a dominant TEM mode of propagation between the two, or with a combination of TEM and LMD, with the TEM mode dominant. A much larger telluric wave can indicate a dominant LMD mode, and this will be demonstrated in the Telluric Transference of Electric Power series. In this experiment the radio-wave and telluric-wave contributed about equal proportions of the received power in the telluric part of the experiment.

Figures 3 below show a range of pictures of the experimental apparatus, measurements, and some of the key setup conditions for both the single wire and telluric experiments. It is interesting to note that in fig. 3.3 the phone on the top of the MFJ-998 shows the live image of the remote camera setup in lab2 to monitor the RX coil and apparatus. The remote camera is connected through local WiFi in lab2, and then to the router in lab1 by wired LAN connection between the two labs. This live remote video monitoring allows operation of the TX system whilst monitoring directly the RX system, and to produce the live inset video in both parts 1 and 2 of the video experiments.

Telluric Ground System Design and Construction

The ground system associated with a TMT system has always been considered as a critical part of the engineering required to make a successful telluric transmission system, with minimal losses and maximum transferred power between the TX and RX coils and the telluric transmission system. Tesla himself noted that it is necessary to get a firm grip on the ground if it is to be resonated by his wireless power system, and a lot of effort was poured into minimising the impedance, or resistance at resonance, of the connection between the ground electrode and bottom-end of the Tesla coil[5]. Subsequently in conversations with Eric Dollard he has pointed out that it is imperative to get as much copper into the ground as possible for any telluric experimentation and get as close to 0Ω as possible, in other words, to minimise the contact resistance of the Tesla coil secondary bottom-end to the transmission medium in the ground. In addition for a true Tesla transformer, as the bottom-end of the secondary is connected to ground by the minimum impedance possible, the top-end of the secondary needs to present the highest possible impedance of the coil at an elevated position above the ground, and preferably with a top-end load such as a metal sphere, ball, or toroid.

Arranged in this way, and according to conjectures and postulation on the LMD mode,  the Tesla transformer ot TMT system forms a complete longitudinal cavity from the high-impedance top-end of the TX coil, through the telluric transmission medium, and up to the high-impedance top-end of the RX coil. It is in this condition that the coherent LMD mode facilitates the very high efficiency transference of electric power between the generator and the load. The Tesla transformer also fulfils the key step of transforming the TEM mode in the primary to the LMD mode in the secondary cavity, meaning that the generator TEM mode is transformed to LMD mode in the single wire or telluric cavity, and then back again to the TEM mode in the primary of the receiver. It is conjectured that the LMD, or longitudinal mode as it is often referred to, forms a standing wave across the cavity with one or more defined null points  in the cavity, and hence as such, is not subject to the same losses as a propagating transverse electromagnetic wave. Some of my own experiments in the Transference of Electric Power series, and the High-Efficiency Transference of Electric Power series, appear to support the existence of the LMD mode, and that indeed very high power transfer efficiency can be established between the TX and RX coils of a TMT system in the close mid-field region.

It remains to be experimented and tested to see if this LMD conjecture can be extended across far-field distances and does indeed result in lower power transmission losses, and hence higher efficiency of power transfer. As a point to note, I do also myself debate the necessity for the lowest resistance connection to ground when the LMD mode is properly established. The coherence across the entire cavity of the LMD mode should not necessarily require a low impedance connection to ground, or even a low impedance telluric transmission medium. This would certainly be necessary if the transmission mode is by TEM propagation, where any higher impedance, mismatch of impedance, absorption and reflection of power, and radiation losses will make for huge loss of power across the distance of the transmission medium. All these factors are certain for TEM power transmission, but not all may apply for a coherent LMD mode properly established over the transmission cavity. This conjecture remains to be confirmed or refuted through experimentation.

Accordingly in my own experiments, and as a starting point for my telluric experiments, I designed and constructed a ground system within the available space, materials, and budget that are accessible to me at this time. From the perspective of getting as much copper into the ground or the lowest resistance to ground, this appeared as the best place to start, that is, to enable maximum possibility of receiving a signal through the ground at distance whether it be by TEM or LMD transmission modes, or a combination of both. The design uses 22mm copper water pipe which gets a good quantity of copper into the ground, and with reasonable surface area, by simply drilling holes and driving in tubes, as opposed to having to dig or excavate large pits in the ground. The essence of the water pipe is that at any time water can be piped through the ground system and down to where the contact between the copper and ground is actually occurring. In addition small holes where drilled along the length of the underground copper pipes to allow water to escape along the length and hence irrigate the soil around the pipes extend into the ground as well as at the end of the pipe. This gives the possibility to prepare the ground system before experiments to irrigate the surrounding underground earth and reduce the ground system resistance to the earth to as low as possible. This water irrigation works well as intended, and after about 1 hour of irrigation the ground system impedance falls significantly.

In order to make measurements of the ground system performance I included a single copper pipe reference where I can measure the impedance between the main ground system and the reference ground system. As this experiment is an introduction to my telluric experiments so far, I will include these measurements in the start of the reported series on Telluric Transference of Electric Power. The preparation of the ground system involves connecting the reference ground to the main ground via plastic water hose, and then first connecting the top-end of the reference to the main water supply. This quickly allows water to flow into an fill up all the pipes in the system, and before the water has a chance to soak away from the ends and through the holes into the surrounding earth. When this is done the water direction is then reversed to fill from the bottom-end connection of the main ground system and left for up to an hour to back-fill all the pipes, soaking away into the ground and reducing the contact resistance between the earth and the copper. The total exposed (above ground) length of the main system is 3m, and the underground copper is ~ 15m. The total physical size of the ground system is less than one-tenth of the wavelength of the generator at the 160m amateur band.

The main and reference system have a copper electrical feed point which is soldered into intimate contact with the copper pipework and does not disturb the water flow within the pipes. The main system is connected by a 4m 0AWG micro-stranded silicone coated cable to the lower end of the TX secondary coil, and for the reference to measurement equipment via a 4m 12AWG micro-stranded silicone coated cable. With irrigation for ~ 1hr, and in the winter months with good rainfall, so the water-table is at its maximum in the area, the impedance of the main ground system to the earth can be as low as ~ 15Ω @ 1.86Mc. The total impedance of the main ground system, as measured with the reference system, and including the 4m 0AWG ground cable between the bottom-end of the secondary and the ground system terminal, is ~ 40-60Ω @ 1.86Mc, dependent on season and irrigation. This is approximately one-third to one-half of the resistance of the secondary coil at resonance, and as such presents a reasonably low and solid connection for the TX coil to ground at the frequency of operation, and was practical to construct and build in the space available. I would have preferred a centre fed star arrangement for physical construction, consistent with many preferred ground system arrangements used by radio amateurs in the MF and HF bands, however my available space did not allow for this, and I adopted a straight design with the same amount of copper underground. All in all the ground system so far has proved to be effective, and I have been able to measure telluric transmission of power and signals over significant distance from the transmitter, which will be presented in the Telluric Transference of Electric Power series.

It should also be noted, and as indicated in the schematic in fig. 2, that the linear amplifier generator is NOT connected itself to the RF main or reference ground system used in the telluric experiments. This is arranged in order not to introduce uncertainty into the source of any measured telluric transmission through the earth. For generator safety during operation the equipment and components of the generator are connected together by their earth chassis connections and then in-turn connected to an isolated line supply earth. This continues to protect the generator equipment and components in the event of an electrical fault, whilst isolating the earth connection from the telluric RF ground system, and hence not influencing or confusing the measured results.

Figures 4 below show pictures of the final main and reference ground system outside lab1, and some from its construction in 2019. For the telluric comparison in this experimental post lab2 uses a dedicated RF ground through a single copper coated steel ground rod, and is typical for use in amateur radio work when connecting a linear amplifier transmitter and receiver. Clearly in this experiment the TX and RX ground systems are quite different in size, copper under the ground, and hence contact resistance between the telluric transmission medium and the RX coil.

Small Signal AC Input Impedance Measurements

Figures 5 below show the small signal ac input impedance Z11 measured directly on the experimental system, and using an SDR-Kits VNWA vector network analyser, as used on many experimental pages on this site. The measurement setup, equipment, and connection to the experimental apparatus is shown in fig. 3.2.

To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Fig 5.1. Shows the input impedance Z11 over the range 100kc to 5Mc for the TX coil primary connected to the VNWA, and with balanced parallel modes with the primary tuning vacuum capacitor set to 396pF. The bottom-end of the secondary coil is connected directly to the main ground system as would be the case in the telluric experiments, and the top-end telescopic aerial is set at its default length of 39mm that sets a wire-length that corresponds to ƒS = 1.87Mc @ marker M2 for the fundamental series resonant mode. This same point was empirically adjusted to drive at 1.86Mc for optimum large-signal tuning. The TX coil resistance at the series mode M2 presents a resistance of 24.1Ω which is conveniently very close to one-half of the optimum generator system output impedance of 50Ω. This could ideally be connected to the generator directly using a high-power 1:2 current balun with minimal if any antenna tuner transformation to the linear amplifier. For flexibility in tuning for this experiment the Palstar antenna tuner was used directly to transform the 50Ω output of the linear amplifier to the 24.1Ω at the TX coil primary input. The lower and upper parallel modes from the TX primary and secondary coil are impedance magnitude balanced, with lower mode ƒL = 1.62Mc @ M1, and the upper mode ƒU = 2.24Mc @ M3. It should be noted that the RX coil for this measurement is also connected and correctly tuned to its own ground system at lab2 in the reciprocal arrangement, but cannot be “seen” at all in this VNWA measurement.

Phase change is consistent with a typical high-Q, loosely coupled and loosely wound, Tesla coil, and the series and parallel modes all occur at a phase angle of ~ 0° consistent with a resonant circuit mode. This characteristic presented in fig. 5.1 forms the base small-signal impedance characteristic for the telluric experiment presented in this post, and also for experiments presented in the Telluric Transference of Electric Power series in the 160m amateur band in the MF band. Lower frequency telluric experiments in the LF band have very different characteristics and will be presented in future posts. For best match to the linear amplifier generator the fundamental series mode ƒS is used as the optimum driving point where most power can be coupled directly into the secondary cavity. At the receiver in telluric experiments both the series and lower parallel mode can be tuned to the 1.86Mc and both are useful for different aspects of the measurement. For signal strength experiments using the radio scanner the parallel mode is best as it presents a high-impedance to the output of the RX coil, which is well suited to maximum incident voltage at the input to the radio tuner. For absolute power measurements using a 50Ω power sensor, in this case the HP 435B with HP 8481H sensor, tuning the RX coil to the series mode is necessary for making power measurements, where the transfer of power between the RX coil and sensor input impedance is best optimised.

Fig 5.2. Shows the characteristics for the complete TMT system connected by the 30m single wire, and without the 500W load connected at the primary of the RX coil. The low impedance of the single-wire transmission medium allows the VNWA to “see” the characteristics of the RX coil reflected into the input impedance measurements. This is particularly useful to accurately setup the TX and RX coils, at least for the TEM modes, where their fundamental series resonant modes can be matched, and the parallel modes can also be matched. Here in this characteristic the parallel modes are shown as balanced, and the series mode is that of the TX coil dominant at ƒS = 1.88Mc @ M4. The system is unloaded at the RX coil and hence this is the highest-Q measurement of the TMT system, where the parallel modes at both the TX and RX are very sharp and also split to give two peaks at the lower mode, and two peaks at the upper mode. The primary tuning capacitors CPTX = 354pF and CPRX = 498pF have been adjusted to bring about the best empirical balance between the parallel modes, and hence equal influence of the parallel modes in all four coils, two primary coils, and two secondary coils. I have discussed and conjectured in Cylindrical Coil Input Impedance – TC and TMT Z11 that balance of these four parallel modes in a TMT system is the optimal starting point to maximise the generation of the LMD mode across the TMT cavity, and that the LMD mode can be further fine tuned by adjusting the parallel modes at both the TX and RX coil.

It should be noted that the frequency split in the upper and lower parallel modes is quite narrow, (as compared to say the TMT system measured in the close mid-field region in High-Efficiency Transference of Electric Power over 1.5m, and show in fig 3.2), which shows the reduced coupling between the TX and RX coil over the longer distance of the 30m single-wire. Over the 1.5m single-wire the lower parallel modes where split by ~ 70kc, whereas here they are split only by 30kc. There are also low impedance series points at M2 = 1.66Mc, and M6 = 2.32Mc which could be alternative driving points for the linear amplifier generator. Both points have significantly higher impedance presented to the generator, and hence M4 remains the best point to drive the TX coil for maximum transference efficiency across the TMT.

Fig 5.3. Here the 500W load has been connected at the output of the RX coil primary, and the series fundamental modes have been finely tuned and balanced using small changes in wire-length affected through the telescopic aerial at both the TX and RX secondary coils. The final tuned lengths of the aerials are TX = 39cm, and RX = 37cm, and these were used as the base tune when needing to reset to a known starting condition. Adding the 500W load has collapsed the parallel modes at the RX coil, although of course they remain part of the actual electrical system at the receiver. The close tuning of the series modes leads to frequency splitting through beat frequencies between the two resonators which results in the double phase relationship seen at markers M2, M3, and M4. Two fundamental series resonant modes, and upper and lower, are now present at ƒSL = 1.85Mc @ M2, and ƒSU = 1.92Mc. The upper series mode formed the starting frequency for the 30m single wire experiment where the input impedance is resistive, RSU = 51.5Ω @ M4 and very close to the untuned system output impedance of the linear amplifier generator at 50Ω. This driven point was subsequently moved to M3 at ƒS = 1.89Mc which yielded a slight increase in transfer efficiency. The parallel modes of the TX coil remain largely unaffected by the split series modes and are balanced with slight adjustment to CPTX = 371pF.

Fig 5.4. Here the matched series fundamental modes have been detuned by increasing the wire-length using the telescopic aerial at the TX coil from 39cm to 50cm. This reduces slightly the lower series frequency, ƒSL = 1.82Mc @ M2, which then becomes the dominant mode with respect to the generator drive. This dominant series mode reduces the input resistance of the TMT system, RSL = 35.2Ω @ M2, and slightly imbalances the parallel mode tuning at M1 and M5.

Fig 5.5. Here the matched series fundamental modes have been detuned by reducing the wire-length using the telescopic aerial at the TX coil from 39cm to 17cm. This increases slightly the upper series frequency, ƒSU = 1.96Mc @ M4, which then becomes the dominant mode with respect to the generator drive. This dominant series mode reduces the input resistance of the TMT system, RSU = 26.9Ω @ M4, and slightly imbalances the parallel mode tuning at M1 and M5, the other way from fig. 5.4. It should be noted that the centre drive point of the upper and lower series modes at M3 remains less impacted by the frequency detune of the series modes, and hence represents the optimal stable drive point over the dynamic range of the experiment with ƒS = 1.89Mc @ M3. The higher impedance of point M3 requires further tuning using the antenna tuner, or is also suitable for 1:4 current balun at the input to the TX primary coil.

Fig 5.6. Shows the effect of increasing the single wire length from 30m to 40m, which also makes the single wire almost exactly a quarter wavelength of the generator drive frequency. The increased wire-length in the cavity has increased the overall wire-length of the TX and RX coils at their bottom-ends, and hence the five resonant points of interest indicated by markers M1-5, have all shifted down slightly in frequency. The centre drive point at M3 now being at 1.86Mc rather than at 1.89Mc. Otherwise the TMT system impedance characteristics remain largely unchanged, and the quarter wavelength length of the single-wire does not have such a big impact as might be at first expected given the complete impedance transformation from a short circuit to open circuit across a quarter wavelength wire. And this is an important point to note, that the length of the cavity is now defined by the quarter wave TX and RX coil plus some of the wire-length at the bottom-end and the top-end that is within the magnetic coupling distance of the coil. For example, if we take just the TX coil and add a single wire at its bottom-end of say 1-2m, this will have a very distinct change on lowering the fundamental series mode frequency ƒS. If we now add a further 5m to the single-wire this further reduces ƒS, but not to the same amount. Adding a further 10m has even less impact on reducing ƒS.

So the impact of adding single-wire length to either end of the coil has diminishing impact to ƒS with increasing length, and this is the product of the wire-length which is within the magnetic field coupling of the coil. And this is what is happening with the increase in single-wire from 30m to 40m. Only the wire length up to about 5m from the bottom-ends of the TX and RX coil have a significant impact on reducing the ƒSL and ƒSU, whilst the 20 or 30m in the middle makes much less difference to the TEM frequency characteristics of the TMT system. So increasing from 30m to 40m single-wire is not really about the quarter wavelength impedance transformation, but rather simply an increase to the middle section of the transmission medium, with only slight impact on the frequency of the five resonant points of interest. This would continue for increasing length of single-wire with diminishing impact on the frequency characteristics until the TEM losses along the wire length collapse the coupling of TX and RX coils.

Single Wire Comparison at Lengths 1.5, 11, and 30m

In this experiment with a 30m single wire in the TMT cavity the best result obtained at 1.89Mc was 200W supplied by the RX coil to the load, for 500W supplied to the TX coil by the generator, yielding a power transfer efficiency of 40%. This is very much lower than that obtained for the 1.5m @ 99%, and 11m @ 96% in the High-Efficiency Transference of Electric Power series. The biggest loss mechanism in this experiment is expected to be radiative losses from the single wire, as the single-wire did not heat up, and the components at the TX and RX did also not heat up. Some power would have been lost in resistive losses along the single-wire length, but the majority of the power would have been radiated from the single wire acting as a long-wire antenna between the two coils. This means that the TEM mode was the dominant transmission mode in the cavity, whereas it has been conjectured in the 1.5m and 11m single-wire experiments that the LMD was dominant and resulted in very low losses along its length, and particularly in the case of the 11m single-wire.

If the LMD mode conjecture is developed further for this experiment, then it is clear that despite careful tuning and adjustment of all the series and parallel modes in the TMT system, and the careful adjustment and exploration of frequency around these modes, it was not possible to engage the LMD transmission mode as the dominant transmission mode, and for as yet unknown reasons. Without the LMD mode the TEM mode leads to considerable radiative losses at the frequency used from the wire length, which is of course why power transmission at high frequencies over large distances using single-wires is impractical when only the TEM mode is involved. It is unclear why the LMD mode could not be engaged in this setup as per the 11m single wire, as nothing else has significantly changed in the experimental apparatus, operation, or measurement method. I do not currently see the increase from wire length from 11m to 30m to have such a substantial change on the LMD mode conditions that would be required to be established, but nonetheless there are clearly other unknown factors in the setup and balance of these modes over single-wires of increasing distance.

Single Wire vs Telluric Transmission Medium

One of the central aims of this experiment was to make a side-by-side comparison of a TMT system, where the transmission medium between the TX and RX is a direct connected single-wire, or a telluric channel through the earth, and where both channels were of comparable distance between the TX and RX. The total length of the telluric channel in this experiment was, 4m TX earth wire + 18m telluric point-to-point + 4m RX earth wire,  or minimum length of 26m. This actual length of the channel may be longer than this, if we consider that the telluric channel may not be a direct point-to-point path between the two ground systems. Nonetheless a 26m telluric transmission channel was considered comparable in length to the 30m single-wire. What we see from the measured results in this experiment is orders of magnitude difference in the transmitted power between the TX and RX with the two different transmission mediums. As already discussed the best result so far for the 30m single wire ~ 200W from 500W efficiency 40%, whereas for the 26m telluric channel the best result was ~ 80mW from 500W or an efficiency of  0.016%. For the 80mW received at the power meter with an optimum impedance match of almost 50Ω between the RX coil output impedance and the power meter sensor, 35mW ~ 44% is from the radio-wave with no connection to the telluric ground system, and 45mW ~ 56% is from the telluric-wave via the ground system.

This enormous difference in power transfer through the telluric ground system implies that almost all of the power at 1.86Mc has been absorbed into the ground, in other words to heat up the ground around the main TX ground system, with very little of it being transferred to the RX ground system. It is expected that the impedance of the telluric connection between the two ground systems for the TEM mode is likely to be much higher than the single-wire. Whilst the telluric system does not have the same radiative losses as the single-wire the power is easily absorbed by the transmission medium, and especially at the higher frequencies being used for this experiment. The reasonably close balance between the radio-wave at 44% and the telluric-wave at 56% suggest to me that the TEM transmission mode is again dominant in this experiment. This is an important point to note, that at the frequency used, we would expect the telluric medium losses to be very high, which they are, but we are also interested in the dominant mode of transmission in the medium. It can also be conjectured that the balance of the radio-wave and telluric-wave can also be used as an indication of the dominant mode. With approximately balanced radio and telluric waves I conjecture that this indicates a dominant TEM mode, whereas with a much stronger telluric wave without loss of received power could indicate a dominant LMD mode. I raise this conjecture here as I have measured much larger imbalances in the radio and telluric-wave in other telluric trials over longer distances which will be presented in subsequent posts, e.g. at 2 miles the radio to telluric-wave proportion was measured to be ~ 1:5 for only 10W of generator input power.

In the 1.5m single-wire experiment in High-Efficiency Transference of Electric Power it was demonstrated that an increase in the impedance of the transmission channel using a single wire no thicker than a human hair, a 40AWG (0.08mm or 80 microns) nickel plated copper wire, actually increased the efficiency of power transfer at 500W. So the concept of increased impedance in the telluric channel is not necesarily a limitation to high efficiency power transfer, provided the LMD mode of transmission is the dominant mechanism. Even if this were the case in the current experiment and the LMD mode was dominant, I would still expect high power loss from absorption into the earth at the frequency being used in the HF band at 1.86Mc. There has been considerable discussion in the field regarding the best frequency for telluric power transfer and/or communication, what frequency the earth is electrically resonant at, and what is the earth’s impedance and admittance to different modes of transmission both over the surface, and deeper into the body of the earth. I will look at these areas in more detail in my next post on Telluric Transference of Electric Power.

Summary Conclusions and Next Steps

In this post transference of electric power has been explored and demonstrated, using a TMT system with two distinctly different transmission mediums between the TX and RX coils. Tuning of the different series and parallel modes of the TMT system have been well explored, and demonstrate many aspects of the TEM characteristics of single-wire transmission line systems. Telluric transference of electric power has been introduced along with the apparatus, method, and forms of measurement required to characterise this fascinating area of Tesla research. From the experimental results and measurements presented the following observations, considerations and conjectures are made:

1. The maximum 30m single-wire efficiency that could be established in this experiment was 40%, where the losses along the single-wire are predominantly radiative from the long wire acting as an antenna, and some resistive losses along the wire length.

2. From the results obtained the predominant transmission mode along the 30m single wire is expected to be transverse electromagnetic propagation, the standard TEM mode of transmission.

3. It is conjectured that the LMD mode, for as yet unknown reasons, could not be tuned as the dominant transmission mode in this experiment, which also led to high losses, and huge reduction in power transfer efficiency. This is directly in contrast with the results obtained in 1.5m and particularly 11m single wire experiments, where the LMD mode was established between the TX and RX coil, with a null node in the centre, and maximum electrical intensity at the top-end of each of the TX and RX secondary coils.

4. The tuning and matching of the series and parallel modes of the TMT system are conjectured as important to establishing the LMD mode, and so far in this experiment, the correct balance of these modes has not yet been established. It is considered that it is possible to establish the correct setup for the LMD mode to be dominant, and that this may result in a much higher transfer efficiency between the TX and RX coils.

5. The 26m telluric transmission channel resulted in very high losses, with a transfer efficiency of no more than 0.016%. These losses are expected to be predominantly through absorption of the transmitted power into the earth at the frequency used of 1.86Mc.

6. The proportion of radio-wave to telluric-wave in the telluric experiment was 44% : 56%, and so it is conjectured that the TEM transmission mode was again dominant between the TX and RX ground system.

7. It is conjectured that the high impedance of the telluric transmission medium , and the connection of the TX and RX coils to the ground, is not necessarily a limitation to the high efficiency of power transfer when the LMD mode is dominant in the transmission medium.

The next step to the single wire part of this experiment would involve working with the TMT tuning and setup conditions, in order to attempt to resolve conclusion 4, and establish the LMD mode as the dominant transmission mode, and in a similar way as was accomplished for the 11m single wire. If this cannot be established then the conditions for the LMD mode, and its limitations, need to be studied in more detail.  For the telluric transmission medium I will be presenting more experiments and results for progressively further distance from the generator and out into the far-field.

Click here to continue to the next part, looking at Telluric Transference of Electric Power – MF Band 2-8 Miles.


1. Tesla, N., System of Transmission of Electrical Energy, US Patent US645576A, March 20, 1900.

2. Tesla, N., Apparatus for Transmitting Electrical Energy, US Patent US1119732A, January 18, 1902.

3. Tesla, N., Experiments with alternate currents of very high frequency and their application to methods of artificial illumination, American Institute of Electrical Engineers, Columbia College, N.Y., May 20, 1891.

4. Tesla, N., Nikola Tesla on his work with alternating currents and their application to wireless telegraphy, telephony and transmission of power: an extended interview, 1916 Interview – ISBN 1-893817-016, Twenty First Century Books, 1992.

5. Tesla, N., Colorado Springs Notes 1899-1900, Nikola Tesla Museum Beograd, 1978.

6. Dollard, E., Condensed Intro to Tesla Transformers, Borderland Sciences Publication, 1986.

7. Dollard, E., Theory of Wireless Power, Borderland Sciences Publication, 1986.

8. Dollard, E. & Brown, T., Transverse & Longitudinal Electric Waves, Borderland Sciences Video, 1987.

9. Dollard, E. & Lindemann, P. & Brown, T., Tesla’s Longitudinal Electricity, Borderland Sciences Video, 1987.

10. Dollard, E., A common language for electrical engineering – lone pine writings, A&P Electronic Media, 2013.

11. Tucker, C. & Warwick, K. & Holderbaum, W., A Contribution to the Wireless Transmission of Power, Electrical Power and Energy Systems 47 p235-242, 2013.

12. Leyh, G. & Kennan, M., Efficient Wireless Transmission of Power Using Resonators with Coupled Electric Fields, Nevada Lightning Laboratory, 40th North American Power Symposium, 2008.

13. A & P Electronic Media, AMInnovations by Adrian Marsh, 2019,  EMediaPress

14. Dollard, E. and Energetic Forum Members, Energetic Forum, 2008 onwards.


 

Telluric Transference of Electric Power – MF Band 2-8 Miles

This experimental post is a follow-on from the Telluric experiment presented in Transference of Electric Power – Single Wire vs Telluric. In that previous experiment a Tesla Magnifying Transformer (TMT) apparatus, consisting of TX and RX cylindrical Tesla coils, were connected together via a 18m point-to-point telluric transmission medium, and with ground connection cables 26m in total between TX and RX secondary coils. In the medium-frequency band (MF) at 1.86Mc, in the mid-field region, 500W input power to the TX coil generated ~ 80mW of output power at the RX coil, from a combination of the telluric-wave and radio-wave. In this new experiment the same TMT apparatus and generator is used, and the telluric transmission medium is extended into the close far-field region at 2 and 8 mile field locations from the TX coil. In both locations natural water features were used as the telluric ground connection for the RX coil, and the transmitted signal could be clearly received, and was shown to result from the combination of a telluric-wave component through the ground, and a radio-wave component above ground. It is conjectured that at the 2 mile location the longitudinal magneto-dielectric (LMD) transmission mode was dominant in the telluric cavity between TX and RX, and the transverse electromagnetic (TEM) mode was dominant at the 8 mile location.

The video experiment demonstrates and includes aspects of the following:

1. Portable Tesla receiver (RX) setup and tuning, using a cylindrical coil tuned in the 160m amateur radio band, for radio-wave and telluric-wave field experiments in the close far-field region.

2. Telluric ground connection using a submerged aluminium metal plate, firstly in a natural lake connected to a river 2 miles from the lab transmitter (TX), and secondly in a man-made reservoir 8 miles from the TX.

3. Small signal ac impedance measurements using a vector network analyser to tune the RX Tesla coil to the series and parallel resonant modes.

4. Fine tuning to different modes, and optimal received signal strength at 1.86Mc, using a telescopic aerial at the top-end of the RX secondary coil.

5. Comparison of radio-wave and telluric-wave measurement by re-tuning the RX coil from the Telluric ground plate connection, to an ungrounded single wire bottom-end extension.

6. At both 2 and 8 miles the CW audio tone could be received and heard at only 10W TX input power.

7. At 2 miles, 6 bars of signal strength were measured at 10W TX power at 1.86Mc for the telluric-wave and radio-wave combined, and 1 bar for the radio-wave only.

8. At 8 miles, 4 bars of signal strength were measured at 400W TX power at 1.86Mc for the telluric-wave and radio-wave combined, and 2 bars for the radio-wave only.

9. The lower parallel resonant mode of the RX Tesla coil was found to receive the maximum signal strength at both 2 and 8 miles.

10. The lower parallel resonant mode was found to be much more sensitive to body and object proximity than the series resonant mode.

11. It is conjectured that at the 2 mile location the longitudinal magneto-dielectric (LMD) transmission mode was dominant in the telluric cavity between TX and RX, and the transverse electromagnetic (TEM) mode was dominant at the 8 mile location.

Video Viewing Note: In the video the telluric-wave (in the ground) is referred to as the ground-wave, and the radio-wave (over the ground) is referred to as the sky-wave, and not to be confused with the amateur radio definitions of ground and sky wave.

The experimental apparatus, generator and operation, and the TX ground system, is exactly the same as that used in Transference of Electric Power – Single Wire vs Telluric, and is discussed and presented in detail, along with the full experiment schematic, in that post. Operation of the generator in this field experiments is via a research colleague at the lab, and setup, tuning, and operation of the generator can be viewed in detail in the single-wire experiment video presented in the aforementioned post.

A key measurement in the telluric experiments which needs some consideration is the process of measuring the radio-wave of a radio transmission. For all radio transmission, and as transmitters are almost always grounded down to earth, the major component of the transmission is the propagating TEM wave from the radio transmitter antenna to the receiver antenna. In relation to a telluric experiment, we cannot assume that all the power transferred from the TX to the RX coil is via the telluric channel through the ground, as there will also be a radio-wave component at the receiver. We also cannot simply remove the bottom-end ground connection of the RX coil to measure this radio-wave component, as this will change the wire-length of the secondary cavity, and hence change its fundamental series resonant frequency, and any connected receiver which is tuned to the transmitter frequency will erroneously show no received signal, simply because the RX coil is not correctly tuned to the transmit frequency.

To accomplish the radio-wave part of the experiment, and as demonstrated in the video experiment, the telluric ground connection is removed from the RX coil, and is replaced with a single wire 10m in length which is NOT connected into the ground or to any other grounded end-point. The telescopic aerial at the top-end of the RX coil is now fine adjusted so that the series mode resonant frequency of the RX coil matches the transmit frequency. This is accomplished by maximising the received signal at the receiver at the correct TX frequency, and then cross checked by VNWA measurement to confirm correct tuning of the RX coil. In this way the RX coil is now tuned to the correct frequency for receiving the transmitted signal, but is also not connected into the ground.

The signal strength now received on the radio receiver, or power meter, is a result of the radio-wave contribution only, and is less than the combined radio-wave and telluric-wave, as can be seen in the video experiment. The proportion of radio to telluric wave can also give a good indication as to the dominant transmission mode involved in the transference of electric power between TX and RX coil. Equal radio and telluric components tend towards a dominant TEM mode of propagation between the two, or with a combination of TEM and LMD, with the TEM mode dominant. A much larger telluric wave can indicate a dominant LMD mode, and this is demonstrated at the 2 mile field location.

Small Signal AC Input Impedance Measurements

Figures 2 below show the small signal ac input impedance Z11 measured directly on the RX coil of the TMT system, and using an SDR-Kits VNWA vector network analyser, as used on many experimental pages on this site.

To view the large images in a new window whilst reading the explanations click on the figure numbers below.

Fig 2.1. Shows the small signal ac input impedance Z11 of the RX cylindrical Tesla coil, connected via the aluminium grounding plate submerged in a natural river-fed lake at the 2 mile location. The grounding plate is connected to the bottom-end of the RX secondary coil via an 8m 6AWG micro-stranded, silicone coated cable. The RX coil was tuned by adjusting the length of the secondary top-end telescopic aerial, as shown in the video, and in this measurement shows tuning to the lower parallel mode, (in this case the parallel mode of the secondary coil), at ƒL = 1.86Mc @ M1. The RX coil is setup without using balanced parallel modes, as with very small signal reception experiments the additional capacitive loading appears to reduce the amplitude of the measured signal via the Sony ICF-2001D radio receiver. At ƒL the input impedance, (output impedance presented to the radio receiver), is RL ~ 1719Ω. The higher impedance of the lower parallel mode is more suited than the low impedance of the series mode, to directly feeding the Sony radio AM external antenna input, and hence the input impedance of the super-heterodyne first stage receiver in the Sony. Maximum signal reception results were consistently accomplished in the field using the lower parallel mode tuned to the transmit frequency of 1.86Mc.

The fundamental series resonant mode here occurs at ƒO = 1.99Mc @ M2, and again can also be tuned to 1.86Mc by longer extension of the telescopic-aerial. A comparison of the receiver measurements were made in the video against the lower parallel and series modes, and it was determined that the lower parallel mode produced the best results for measurement with the Sony radio receiver, and the series mode would be better for direct power measurements using the HP435B with HP8481H thermocouple power sensor which has a 50Ω input impedance. For the most accurate direct power measurements the output of the RX coil should ideally be matched to the 50Ω input impedance of the sensor, ensuring maximum power transfer from the RX receiver coil to the HP power measurement system. If and when higher powers can be measured using direct power measurement, then a 2:1 current balun would be suitable to affect quite a good match between the RX coil primary output RS ~ 29.6Ω, and the HP power sensor at 50Ω. The upper parallel mode ƒU = 3.96Mc @ M3 originating from the primary coil, cannot be used in this particular experiment as it cannot be tuned down sufficiently low to 1.86Mc using either additional wire length (lowering the series mode), or loading the RX primary coil directly with parallel capacitance.

Fig 2.2. Here the RX coil at the 2 mile location has been tuned to the lower parallel mode ƒL = 1.86Mc @ M1 with the 10m ungrounded single wire at the bottom-end of the secondary coil, and adjustment of the wire-length of the secondary via the telescopic aerial length from 39cm to 45cm. The Q of the RX coil is noticeably higher from being ungrounded and the lower parallel resonant mode impedance is higher at RL ~ 2666Ω. The series resonant mode ƒS = 1.99Mc @ M2 is slightly stronger, and has a lower impedance RL ~ 17.5Ω. Otherwise the characteristics are very similar to when the aluminium telluric ground is being used. This tuned characteristic using the 10m ungrounded single wire was used to measure the radio-wave component of the received signal, which at the 2 mile location, was much lower than the telluric-wave component.

Fig 2.3. Shows Z11 of the RX coil connected via the aluminium grounding plate submerged in a reservoir at the 8 mile location. The parallel mode is here tuned to 1.85Mc rather than 1.86Mc, and there is a consistent 1Hz tuned error throughout this experiment at the 8 mile location. When checked the 1Hz difference did not make a discernible difference to the received signal strength or reception at the field location when using either the lower parallel or series resonant modes. It is interesting to note that the Q of the RX coil system is higher at the 8 mile location, and is more similar to the 10m single wire result in fig. 2.2, than the telluric-plate result in fig. 2.1. It could be considered that this may indicate that the telluric connection to the earth was not as good at the 8 mile location, something which was certainly reflected in the much reduced received signal strength measurements.

Fig 2.4. Here the series mode is now tuned at 1.85Mc, and it is interesting to note that the series mode impedance is again not much higher than that for the 10m single wire results in fig. 2.2, again suggesting that the telluric connection is not as good at the 8 mile location. So both the lower parallel mode and the series mode are closer here to the 10m single wire results achieved at the 2 mile location, and that may suggest that the 8 mile location was more suited to reception of the radio-wave, and less to the telluric-wave. This was indeed what was measured, that the telluric-wave and radio-wave contributed almost equally to the received signal strength at this location, and a lot of transmitter power was needed to get a well-defined signal strength measurement.

Fig 2.5. Shows the balanced mode of the RX coil, and with the series resonant mode tuned to the transmitter frequency. Note that for clarity the magnitude of the impedance scale, |Z| (blue) has been increased from the previous 500Ω/div to 2000Ω/div. The parallel modes from the primary and secondary coil were balanced using a primary loading capacitance of CPRX = 282pF, and this balanced condition in a TMT has been shown to be beneficial to achieving a very high transfer efficiency in single wire mid-field region experiments in the High-Efficiency Transference of Electric Power series. In this telluric experiment, in the far-field region, this balanced condition was found to introduce too much loading in the RX coil given the very small signals being received, which led to reduced signal strength measurements.

The capacitive loading in the primary coil was removed, and appears sub-optimal for these types of very low power level telluric reception measurements. If and when higher power can be transferred via the telluric transmission medium, the balanced mode may be necessary to maximise the LMD transmission mode, and hence the received telluric-wave. It should be noted that the TX coil is tuned and driven by the generator at its series fundamental resonant mode at 1.86Mc, and with the lower and upper parallel modes balanced using primary capacitive loading CPTX = 403pF, which was found consistently to be the most efficient setup for the TX coil and linear amplifier generator, used in both in this telluric experiment and the experiments presented in Transference of Electric Power – Single Wire vs Telluric.

Fig 2.6. Here it was tested to see the maximum balance that could be accomplished between the upper and lower parallel modes, and whilst keeping the lower parallel mode tuned to the transmitter frequency. This characteristic was tuned using a primary loading capacitance of CPRX = 60pF, a significant reduction in loading capacitance from the full balanced mode in fig. 2.5. This produced better signal strength results than the full balanced mode, but still not as good as the unloaded results with no additional primary tuning capacitor. At these very low reception powers it was concluded that the balanced mode simply attenuates the signal too much, and especially in the case were the telluric-wave is not very strong, and the LMD mode is not dominant.

Telluric Transmission in the High MF Band Far-Field

In the first field location 2 miles from the transmitter it was possible to clearly receive with 6 bars of signal strength at only 10W TX power at 1.86Mc for the telluric-wave and radio-wave combined, and 1 bar for the radio-wave only. The attenuation of the signal at 1.86Mc under the ground appears enormous, and it was considered in the previous experiment Transference of Electric Power – Single Wire vs Telluric that this loss is dominated by absorption of the transmitter power by the earth directly surrounding the main telluric ground system in the high medium-frequency band. In the previous experiment only 18m from this telluric ground system the measured power had already dropped from 10W TX power to 1.25mW at the RX coil.

So transmitted power in the earth surrounding the telluric ground system has already reduced by almost 4 orders of magnitude even before it is only 10s of meters away from the ground system connection. When we consider the result achieved 2 miles away the power would have dropped into the micro-watt level to produce the kind of signal strength received by the Sony radio receiver, and so we can conjecture that the transmission over the 2 miles was actually more efficient, than the transmission from the TX secondary coil through the ground system and over the distance of a few 10s of metres. This may also imply that there is very considerable power losses in the interface between the copper of the ground system and the earth, and even with significant water irrigation of the ground system, and relatively low measured impedance at the transmitter frequency.

It is very interesting in the 2 mile location that there was also a large difference in the received combined telluric and radio-wave at 6 bars, and the radio-wave at 1 bar, where in both cases the RX coil was tuned at the lower parallel mode to the transmitter frequency through adjustment of the coil wire length. Again in the previous 18m telluric experiment the proportion of telluric-wave to radio-wave at 10W was 0.7 mW : 0.55 mW, where both components are much closer and contributing approximately equally to the transmission of power from TX to RX, with only slight emphasis on the telluric-wave. In the 2 mile field location the ratio of signal strength telluric to radio is 5 : 1 which we can also conjecture may result from a more dominant LMD mode across the telluric cavity formed by the TMT system.

We do also need to consider the possibility that the radio-wave encountered significant obstacles in the 2 mile TEM propagation, reducing significantly the radio-wave component at the RX coil, but I would suggest that the combination of the two results regarding the better power transmission efficiency over the 2 miles distance than the 18m distance, the relatively close far-field distance, and the large signal strength ratio 5 : 1, could point towards a dominant LMD mode, and a preferential telluric transmission channel, over and above the TEM mode radio propagation channel.

In contrast at the 8 mile man-made reservoir location, although the signal tone could just be detected at 10W TX power, it was necessary to use up to 400W of TX power to get reasonable signal strength up to 4 bars. It was also noted that the ratio of telluric to radio-wave components was again around 1 : 1, and the far-field transmission distance had not significantly increased by going up to 8 miles at the transmitter frequency at the top-end of the MF band. It is considered here that the telluric channel/connection at the RX coil end was not as good as for 2 mile case, and especially in taking into account that the water-body used for the telluric ground was both man-made and may not be so well connected to the earth’s aquatic system. It is conjectured that the LMD mode was not established as dominant in the TMT transmission cavity, and that power reception at 8 miles was dominated by the TEM mode of far-field radio-wave propagation.

It must also be considered that the two field locations presented so far were not selected for any special water-table, river inter-connection, underground aquatic properties or channels, or for specific earth and rock type and composition. Both locations are in limestone regions and both are connected to water bodies, the 2 mile location being a natural river-fed lake, relatively close to the underground source of the river (a further 2 miles, so approximately 4 miles to the river source from the transmitter). The 8 mile location, being a man-made reservoir with a river tributary feed and outlet, is a further extension in the same direction from the transmitter. So the 8 mile location is essentially 6 miles further on from the 2 mile location, and 4 miles further on from the natural river-source of the 2 mile location.

Summary Conclusions and Next Steps

In this post, telluric transference of electric power has been explored and demonstrated in two different field locations in the near far-field region from the transmitter at 1.86Mc in the high MF-Band.  In both field locations signal strength could be measured at the transmit frequency in both the telluric-wave and the radio-wave at only 10W generator power. There was a vast difference in power required in each location to achieve approximately the same measured signal strength readings, 10W TX power with 6 bars at 2 miles, and 400W with 4 bars at 8 miles, with all other aspects of the TMT apparatus kept constant other than the field location telluric ground connection, and the over-ground terrain profile between the TX and RX. From the experimental results and measurements presented the following observations, considerations and conjectures are made:

1. The LMD mode is conjectured to be dominant in the 2 mile location based on the the large ratio between the measured telluric-wave and the radio-wave, and on considerations on telluric channel/cavity losses both for this experiment, and the previously considered 18m telluric channel.

2. The TEM mode is conjectured to be dominant in the 8 mile location based on the equal ratio of the measured telluric-wave and the radio-wave, and the large input power of 400W needed to get adequate measured signal strength, and on comparison with the very similar telluric experiment results in the 18m telluric channel.

3. The telluric connection quality to the earth through the type of water-body, is conjectured to be the most likely difference between the very different results of the two field locations. The difference in distance of 6 miles is not considered to be the major factor in the large difference in the location results.

4. The underground water inter-connection between the TX and RX is considered to have a significant impact on the quality of the telluric transmission medium between the two ground systems.

5. The impact of the earth soil and rock type and composition is as yet unknown on the telluric channel quality.

6. High losses will occur in the ground system to earth interface, and the telluric transmission channel/cavity with higher transmitter frequencies in the MF band. 1.86Mc appears far too high for any significant power transfer by the LMD mode in a telluric cavity.

7. Telluric transmission via the LMD mode is conjectured to be more efficient than by the TEM mode, and that with a sufficiently low frequency and a properly arranged LMD cavity in the TMT apparatus, it may be possible to transfer larger quantities of power in the far-field with better efficiency than could be accomplished using an overground wireless mode or radio-wave.

Next steps are to further explore Telluric Transference of Electric Power at different field locations both in the close far-field, and then at further distances from the transmitter, both at the same presented high MF-band frequency of 1.86Mc, and then at lower frequencies, and ultimately if possible down into the LF-band where Tesla was working with his own experiments. Lower frequency experiments present considerable challenges, including TMT size and scale, generator type and compatibility, radio regulation and licensing, availability of field locations, and resourcing and funding. If these challenges can be overcome then it may be possible to finally confirm or refute the possibility of high-efficiency telluric transference of power, and understand in much greater detail and accuracy the legacy that Tesla has left us to explore.

Click here to continue to the next part, looking at Telluric Transference of Electric Power – Brookmans Park AM Radio Transmitter.


1. A & P Electronic Media, AMInnovations by Adrian Marsh, 2019,  EMediaPress

2. Dollard, E. and Energetic Forum Members, Energetic Forum, 2008 onwards.