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Date: Fri, 29 Mar 2002 15:35:19 -0500
To: rsgb_lf_group@blacksheep.org
From: "Larry Kayser" <kayser@sympatico.ca>
Subject: LF: loop resonant frequency
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Tuning a large loop to resonance and measuring the loop inductance is easy 
without any instruments but a receiver and a calculator.

Just couple to the loop with a toroid and put a silver mica bank of 
capacitors in series with the loop.  Feed a receiver and tune for peak in 
the noise.  Once you find a noise peak the standard resonance formula with 
the known capacitance will tell you the inductance of the loop.  To check 
it out, and what I did here, was to setup a resonance on 138.83 and another 
on 135.922.  The mathematics works very precisely down to less than 30 pf 
ambiguity, in my case just about half a kHz.  The difference is a small 
plug in bunch of small value silver mica capacitors.

Larry
VA3LK

I did not originate this, Bill, VE2IQ did many years ago.