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Old April 17th 04, 09:05 PM
John Woodgate
 
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I read in sci.electronics.design that James Meyer
wrote (in ) about 'A neat
and compact way to generate RF harmonics...', on Sat, 17 Apr 2004:
On Sat, 17 Apr 2004 17:26:15 +0100, John Woodgate
posted this:

I read in sci.electronics.design that James Meyer
wrote (in ) about 'A neat
and compact way to generate RF harmonics...', on Sat, 17 Apr 2004:
IOW, the Q without the probe will be higher than the Q when you insert
the probe to measure the Q.


Use an inductive current pick-off. That how the Marconi Instruments 1245
series Q-meters work(ed).


Nevertheless, *ANY* method used to probe the field associated with the
resonator will load the resonator and degrade the Q.

IIRC, the Marconi unit used a 10 nH inductor (maybe less) made of a
short length of silver wire, gold-plated to eliminate sulfide attack.
The effect on Q would be minimal in the extreme.
--
Regards, John Woodgate, OOO - Own Opinions Only.
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The bad news is that everything is prohibited.
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