Re: Measuring Unloaded Q of Loop Antenna?


"Bill Bowden" <wrongaddress@xxxxxxx> wrote in message
news:f0885697-6c81-4c90-835e-5817c55e30ff@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
What is the best way to measure unloaded Q of a tuned LC circuit (AM
loop Antenna) without a Q meter?

I tried a scope and generator and loosly coupled the generator to the
loop, using a single turn of wire and 50 ohm resistor, and monitored
amplitude against frequency, but I get different results depending on
the setup. The scope probe is 10X. The frequency of interest is 500KHz
to 2 MHz.

How can I accurately measure the Q of the circuit without a Q meter?

-Bill

Yep, each measurement can turn out different. The pleasing upside is
acknowledging that the most accurate test setup was the one that returned
the highest Q value!.
http://www.crystal-radio.eu/enqmeting.htm describes in great detail what
Mike has already noted. Also look at the series of "LC experiments".


.

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