secondary frequency problem (fwd)

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Date: Tue, 18 Sep 2007 13:53:32 +0100
From: Chris Swinson <list@xxxxxxxxxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: secondary frequency problem

Hi all,

I spaced wound a coil which according to javatc and my own workings, should 
be around 2mhz.

However, when testing on my signal generator, I seem to find the frequency 
is about 800khz with a harmonic at about 1.2mhz. I can only get to 2mhz on 
my signal generator, but the voltage on the coil keeps dropping.

The voltage ins and outs are as follows...

10mv = 140mV  (x14)
20mV = 325mV (x16)
40mV = 700mV (x17)
80mV = 1400mV (x17.5)
1V    =  17V (x17)
2V =     35V (x17)

The "gain" seems to go form 14 to about 17 for some reason. I would have 
thought the voltage gain would have been a lot higher aswell.

Also seems strange that there does not seem to be any real relation to input 
volts vs. output volts, the gain is always about 17. I would have expected 
double volts in = double volts out or something along those lines, but does 
not appear to hold true.

going form 10mV input to 140mV, then double the input to 20mV would have 
expected 280mV output. In any case the figures are hard to crunch as the 
gain is altering a fraction which is probably throwing the results a little. 
Going from 40mV to 80mV seems to work out better, x2 input (40mV to 80mV) 
gives 700mV & 1400mV output. so it holds true I think that double volts in = 
double volts out ??

I think the actual gain is a fraction off 17, though it is hard to read 
volts exactly on the scope also. so x17 is pretty close. I guess with 10KV 
input I would obtain 170KV output. So does my x17 figure = the Q of the coil 
?

JavaTC states the Q as 1,000 which does not seem right. Also I still do not 
understand the frequency problem. JavaTC says 2.7mhz. I don't know if that 
is true as I can't get past 2mhz on my signal generator, but 800khz seems to 
be the figure. 1.2mhz almost does nothing, and volts just keep dropping 
after that. below 800khz it looks like about 300khz is another harmonic but 
it is hard to tell. So assuming the coil is 800khz, why does it calculate as 
2.7mhz ??

Cheers!
Chris