Re: resonant freq.

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

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

Hi D.C.,

On 7 Jul 2002, at 12:49, Tesla list wrote:

> Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<DR.RESONANCE-at-next-wave-dot-net>
> 
> 
> Inject a signal into the bottom of the secondary coil and then, using a
> scope probe, hold a small 4-5" long piece of wire near the top of the coil's
> toroid --- 1-2 in. away but NOT TOUCHING the sec. coil  This antenna will
> pick up the signal and give you the resonant freq on the scope.  You could
> also just use a 5 meg resistor between the scope probe and the toroid.
> 
> The lowest freq you can find will be the resonance point.

I'd say that a couple of inches away from the terminal is far too 
close to give an *accurate* figure (unless the coil is going to be 
that close to something else while running) and 5MOhms is too much 
loading. I suppose it depends how accurate you want to be. I normally 
won't have a probe closer than 3 feet (or more if I can get a 
readable signal).

Regards,
malcolm