Re: toroid capacitance

To: tesla-at-pupman-dot-com
Subject: Re: toroid capacitance
From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
Date: Wed, 13 Nov 1996 08:10:37 -0500

>Date:          Sun, 10 Nov 1996 22:31:18 -0700
>From:          Tesla List <tesla-at-poodle.pupman-dot-com>
>To:            Tesla-list-subscribers-at-poodle.pupman-dot-com
>Subject:       toroid capacitance
>Reply-to:      tesla-at-pupman-dot-com
>
>>From chip-at-poodle.pupman-dot-comSun Nov 10 22:30:55 1996
>Date: Sun, 10 Nov 1996 21:52:15 -0700 (MST)
>From: Chip Atkinson <chip-at-poodle.pupman-dot-com>
>To: Tesla List <tesla-at-poodle.pupman-dot-com>
>Subject: toroid capacitance
>
>Greetings,
>
>How does one measure the capacitance of a toroid?  The only way I can 
>think of doing so is to measure the inductance of a secondary without the 
>toroid, and then attach the toroid and measure the frequency of 
>resonance.  From this, work backwards to get C.  Any other ideas?
>
>Chip

>=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Chip Atkinson 
> http://bhs.broo.k12.wv.us/homepage/chip/info.htm
> --- Everyone is someone else's weirdo. ---
>=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Chip,

To determine the equivalent capacitance of an unknown topload I 
install it on the secondary resonator and using a signal generator and 
o-scope, measure the Fres of the combo.  Then I remove the topload 
off the resonator coil and attach a vacuum variable cap to the hot 
end and ground.  I tune the variable cap until I achieve the same 
Fres and then after disconnecting this cap from the coil, using a 
capacitance meter, I measure the value of the variable capacitor at 
the chosen setting.

rwstephens