[Lowfer] Interesting finding

[Bill Ashlock]

Jay, and others,

I was checking out some resonant capacitors for the Medfer loop tonight on 
the bench and found that my faithful silver mica caps aren't so faithful at 
1.7mHz, after all.

Just for the heck of it replaced my reference 810pf, 500v cap with a 
paralleled small 470p and a 330p that I found laying on the bench. The Q of 
the test loop improved noticeably! Then I made up a combo of four small 180 
and 220s micas that totaled about 800pf. The Q was even higher. Now it 
really gets good: I replaced the micas with three tiny paralleled 270pf, 
50v, COG ceramics and the Q increased by almost 20%!

I could never seem to reach the calculated the Q for the test loop (8T, 1/4" 
tubing, 8"diam), or the outside loop, so the capacitor must be a good part 
of the reason. Figure I need an ESR of about a 0.02 ohm and I don't think 
micas can do that, at this freq.  Suppose I'll have to build my own 
capacitors even though the power is only .1w!!  Ideas?

Bill A

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