Re: Tesla Coil RF Transmitter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Tesla list wrote:
>
> Original poster: "Dan" <DUllfig@xxxxxxxxxxxxx>
>
> Ed:
>
> Tesla said that he measured standing waves set up by lightning
> discharges. He said he could also set up standing waves with his
> transmitter. Standing waves can only occur if the reflected wave
> coming back at you is substantially of the same intensity as the
> transmitted wave. This is of fundamental importance, because if the
> waves are the same strength coming back as going out, Tesla was right
> when he said that the earth has negligible attenuation.
>
> So the big question is: Was Tesla right? did he in fact measure
> standing waves, or was it another phenomena? If he was right, and you
> can indeed set up standing waves, it would mean that the energy does
> not dissipate as you say. Otherwise it does.
>
> This question will not be settled until someone tries to duplicate
> Tesla's experiments, and find out one way or the other.
>
> Dan

	I agree with your statement that existence of observable standing waves
requires low-loss reflection or interference.  The rest is
questionable.  His observations on lightning can be duplicated by anyone
who wants to sit around Colorado Springs and observe the recurrance of
lightning.  The best explanation I've seen of what he observed is that
the effects were meteorological in origin (lightning producing clouds
tend to last for a few minutes, dissipate, and then repeat at more or
less regular intervals).

	As for his setting up standing waves around the earth, I don't have a
quote for that but suspect that he did say it.  I can't imagine any
instruments sensitive enough for observing this, either then or now.
There would be no way to make such measurements with a spark gap excited
coil since the only way that wave interference can occur is if the
interfering signals are pieces of the same wave train and this wouldn't
be possible with the pulsed RF from a TC; no single discharge lasts
anywhere near as long as the round trip time around the earth.  Even if
he had a continuous wave train (he knew how to produce them but don't
remember anything about his having done so at CS) he would have had to
set up his ultrasensitive receiver far enough away from the transmitter
that the signals from it wouldn't overwhelm the receiver.  I've never
seen any mention of his having done that.

	I suppose it would be possible to claim that he didn't tell us
everything he did and that he secretly invented marvellous measuring
instruments with sufficient sensitivity and speed of response to do all
this and used it in his experiments.  I don't remember his claiming this
and wouldn't believe him if he said he had.

Ed