Re: Useful work and fun with Tesla apparatus.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Al,
       In effect, the waveform received is a series of low duty cycle 
burst at Fr. Sort of AM overmodulated or interrupted carrier. I was 
suggesting a rather low frequency filter whose output was rectified 
and smoothed. Envelope detection rather than RF detection. The filter 
would have a rather low frequency response so maybe the idea wouldn't 
work. I simply thought it might be worth a try. I expect the maths 
might shout loudly against the idea.
 
On 29 Mar 01, at 7:52, Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <uncadoc-at-juno-dot-com>
> 
> Malcolm, All ,   What would you suggest as a starting point for a
> filter resonant at gap fire frequency at the receiving end for a
> remotely fired Tesla receiver. What kind of filter could this be? 
> Should it be an adjustable filter?  We use a ferrite rod inside the
> separate tuning coil now, but it seems to not make a great difference.
>  And where should this 'tuning' coil be placed in the circuit?  Should
> it be installed in the remote primary where the ferrite based coil is
> now(where the spark gap of the primary sending coil would be as a
> reference)?

That is where I would place it.

  We are using a 7 point R.Q. copper fitting(Consisting of
> eight 3/4 inch copper couplings) gap at this time on the sending coil,
> with the thickness of a postcard (more or less)between them.  I can
> supply our existing coil specs(winding wire size and coil diameter and
> length) if you need them, but I am not good at the math.  Also, I am
> puzzled that we cannot get a small A.C. fan motor to operate, try as
> we might, what could we be missing here with our attempt to run an
> A.C. small refrigerator motor, the kind with the copper ring run
> across the laminations.     Al.

AC motors generally run using frequencies far lower than the resonant 
frequency of a coil The frequency response of the windings is far too 
low to deal with 100kHz+. Also, the power delivered on a continuous 
basis is relatively miniscule due to the low duty cycle of the 
transmitted signal. I have only got *tiny* DC motors to run when the 
coil output is rectified and smoothed.
 
Malcolm