Re: GM HEI

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Rocky,

I have a schematic of my GM coil setup at:

http://hot-streamer-dot-com/TeslaCoils/Misc/GMHEI/sch.gif

Bob also sent me some data that I will post in awhile.

Measuring the frequency of GM coils is a bit tricky since you cannot
separate the primary and secondary coils.  You pretty much have to connect
up the secondary with terminal and all as you want it and then stimulate
the primary to find the frequency.  A signal generator (perhaps with an
audio amplifier) can drive the cored or uncored primary and then an antenna
probe to a scope should be able to find the resonance.  One can then put in
a primary capacitor, disconnect the secondary connections, and tune the
primary to the frequency.  These coils are harder to tune since you only
have one primary inductor tap.  You have to vary the primary capacitance
for tuning.  I added or subtracted 0.1uF caps and ended up with 1.7uF.

Cheers,

	Terry


At 04:50 AM 1/18/2002 -0700, you wrote:
>not to sound TOO newbie'ish... but how does one measure the resonant freq.
>of the coil?
>
>/me has an idea  !!!
>
>----- Original Message -----
>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Thursday, January 17, 2002 12:45 PM
>Subject: Re: GM HEI
>
>
>> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>>
>> Hi Luc,
>>
>> Without the core it's about 10kHz.  I don't know what it is with the core.
>>
>> Cheers,
>>
>> Terry
>>
>>
>> At 12:05 PM 1/17/2002 -0500, you wrote:
>> >Hi Terry,
>> >
>> >Do you ever try to measured the resonant frequency of a GM HEI
>> >coil with and without the core.
>> >
>> >
>> >Cheers,
>> >
>> >Luc Benard
>> >
>>
>>
>>
>