OldScientist's demo (re-post)

[Deco56]

:::::::::::::::THIS IS A REPOST FOR EXPOSURE PURPOSES::::::::::::::::::::

Hey guys,

I have posted on this subject before, and not to beat a dead horse, I would like some final clarifications before I indeed try to replicate this demo.

https://www.youtube.com/watch?v=wjz-5Lqtxow

That's the demo I am wishing to replicate.

Just a few bullet points I need to answer to fully grasp an understanding and finally replicate under supervision of my supervisor....

- What would a circuit diagram of this set up consist of? Is it just a primary and secondary wound with certain turn ratios etc? Could someone list a typical design dimension? Is inter-turn capacity or inductance crucial? What about about surface area of conductors?

- I assume primary connected to signal generator. These signals are square waves (pulsed)? Is the frequency defined by duration of wave train or relaxation time? What characteristics are most important from input signal? Oscillating nature? Quarter wavelength frequency of seconday coil?

Input is pulsed, but secondary waveform still remain sine waves?

- What is the terminals of secondary connected to? Just some measurement devices?

-Is this wireless DC transmission Tesla and Dollard talked about? Does square inverse law apply?

-Why doesn't this coil need a reflecting capacitor at end of secondary?

-What is typical power output of signal? Is high voltage necessary?

-A typical radio can receive this fine, which makes sense, it responds to induction....but wouldn't a reverse wound tesla coil do even better? or is this only for power distribution?

My professor is interested, please leave any comments you think will be helpful so I can replicate this. Equipment is not a problem, crucial factors are design dimensions and signal....

MAIN QUESTION:

What modification needs to be made (if needed) of the Tesla coil to make it compatible for communication purposes to conventional radio?

A step-by-step of basic procedure to reproduce this experiment should not be too complicated considering the equipment....

I noticed it is a bifiliar primary coil and secondary is grounded, but no top load...

[Deco56]

Bump ! ..........

[dR-Green]

The metal tins are inside the oscillating electrostatic field produced by the coil so nothing is being blocked. If the tin is oscillating within and with the field then the radio antenna inside the tin is surrounded by the signal. Hence the signal isn't going through the tin, but it's reaching the radio via the tin.

Also some things are already answered here:

http://www.energeticforum.com/eric-d...ification.html

Primary input waveform can be sine (AC). Power output depends on input. High voltage is not necessary.

What is the terminals of secondary connected to? Just some measurement devices?

Terminal capacitance, extra coil, or nothing.

What modification needs to be made (if needed) of the Tesla coil to make it compatible for communication purposes to conventional radio?

I suppose a vertical wire instead of terminal capacitance.

[Deco56]

Excellent, thank you.

Eric said to use the equations in "Crystal Radio Initiative" to calculate dimensions. In another video I saw his dimensions for secondary is 35 cm long on 50 mm diameter core with 0.5 mm wire. I put this into a coil calculator and got that it was 104 meters long, but that disagrees with the values I get from Eric's formulae, but I'll keep working.

Finally, OldScientist claims this only works in the near field. Could the same be achieved in far-field with a Tesla receiving coil in the box? I guess square inverse law would apply for power in terms of distance.

Good to know extra coil is not needed for this to work (I hope) because I do suspect he has one off-camera. The square pulses seem important too. How is frequency defined for impulse? Duration of excitation or relaxation?

[Joit]

Deco
Do you think this coil at his Video shown here has something to do with one he use at his expermient ?
https://www.youtube.com/watch?v=bRbN5lc-ZeU
He says something, that he used a 5:1 ration here and a bifialr coil as primary.

[Deco56]

Yes Joit,

From what I know, the secondary is a 35 cm long coil on 50 mm diameter core with 0.5 mm magnet wire with total length of 104 m. Primary is indeed bifilar wound speaker cable. I also think there is an extra coil off-camera but apparently this is not critical for performance...

[dR-Green]

Excellent, thank you.

Eric said to use the equations in "Crystal Radio Initiative" to calculate dimensions. In another video I saw his dimensions for secondary is 35 cm long on 50 mm diameter core with 0.5 mm wire. I put this into a coil calculator and got that it was 104 meters long, but that disagrees with the values I get from Eric's formulae, but I'll keep working.

Finally, OldScientist claims this only works in the near field. Could the same be achieved in far-field with a Tesla receiving coil in the box? I guess square inverse law would apply for power in terms of distance.

Good to know extra coil is not needed for this to work (I hope) because I do suspect he has one off-camera. The square pulses seem important too. How is frequency defined for impulse? Duration of excitation or relaxation?

Never mind what other people are doing, just use Eric's 20 turn secondary coil calculations that are on the Coils Compendium thread. TheOldScientist's coil doesn't have any special characteristics, and even if it did it would make no difference to the desired effect in this case.

Also forget coil calculators, basic mathematics will give you the answers, and then you can see how. Pi times diameter gives circumference. Circumference times number of turns gives conductor length. If you attended school at the age of 15 then you were taught all the skills you need. Use google to refresh your memory.

I heard what Eric said about it in the interview but I'm not sure that he's seen the video so I stick to my opinion in this case. It only works in the near field because the tins are WITHIN the alternating electrostatic field, and that's how the antenna that's INSIDE the tin is receiving the signal. When the tins are taken beyond the alternating electrostatic field, reception ceases. If anything was penetrating the tins, then the AMPLIFIED portable radio should still receive sufficient signal. But it doesn't. So inverse square law applies as distance increases from coil. The transmission medium is supposed to be the earth, where inverse square law does not apply.

Waveform isn't particularly important as sine and square will both work. Frequency is defined the same way universally - the period between one point in a cycle and the same point in the next cycle. The time between each "on" event is equal to the time between each "off" event, so it doesn't matter what you use to measure it as long as you start and finish in the same place.

[Joit]

Deco,
Dont know exactly what he meant about the Ratio, but i think he is talking about the windings for the ratio. Not sure how importend the diameter is, and maybe the distance from primary to secondary plays a part too. He said there also that he had to optimize it (ratio?) until it worked better.