Re: Secondary Resonance LC and Harmonics.

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Original poster: "Chris Rutherford" <chris1@xxxxxxxxxxxxxxxxxxx>

Hi All,

I've just done some more measurements, this time with a square wave and 
looking at the harmonics on that.  This time it resonates at 200KHz (wave 
superimposed on square wave).  For this test I connected my sig gen to the 
base of my TC using a 1K resistor, and put my scope probe on the resistor 
to TC connection.  I injected a square wave and there was a harmonic at 
approx 200KHz.  I then set the sig gen to sine and tuned up to 200KHz, 
where sure enough there was a resonant area.

So now my TC has 3 resonant frequencies, which one is the one that most 
people go by??

Thanks

Chris
----- Original Message -----
From: <mailto:chris1@xxxxxxxxxxxxxxxxxxx>Chris Rutherford
To: <mailto:tesla@xxxxxxxxxx>Tesla list
Sent: Saturday, June 25, 2005 6:34 PM
Subject: Secondary Resonance LC and Harmonics.

Hi All,

I've just wound my first secondary, and in my eagerness I ignored most 
guidance and just wound as many turns as possible on a piece of 3.5' x 4" 
tubing.  It turned out to be approximately 2K turns (gulp).

I managed to get my hands on a nice stainless steel sphere, which sits 
nicely on top.  I was just 'playing' with my scope and signal generator, 
when I discovered that when I set the sig gen to oscillate at 76KHz or 
416KHz I don't need to connect it to the coil in order to show the signal 
on my scope, I only need to touch the probe and the signal magically gets 
on to the coil and scope!  - I'm guessing that my coil and top sphere are 
acting as a tuned LC tank circuit, with a resonant frequency of 76KHz and a 
harmonic of 416KHz.  Either side of these frequencies the signal drops off.

Does this make sense?  Has anyone else experienced something like 
this?  How *badly* tuned is my coil?  Should I take some turns off it (not 
yet varnished)?

Thanks

Chris