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Author Topic: Q Meter Utilities  (Read 372 times)

K6STI

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Q Meter Utilities
« on: February 22, 2020, 07:36:55 AM »

I've written some Windows utilities for the HP 4342A Q meter. They should be useful with other Q meters as well. They are particularly useful for measuring large coils at low frequencies.

If an inductance is too large to resonate with a Q meter's variable capacitor at the frequency of interest, you can add an auxiliary capacitor to achieve resonance. However, even if the Q of the auxiliary capacitor is very high, it can significantly alter indicated Q. For example, if you use a 3000 pF auxiliary capacitor with a Q of 3000 to augment a variable capacitance of 300 pF and the indicated Q is 600, the meter would read 733 if the auxiliary capacitor had no loss. All that's needed to correct indicated Q is the capacitance and Q of the auxiliary capacitor. You can use the Q meter to measure both. The utilities in this package perform the necessary calculations.

http://ham-radio.com/k6sti/hp4342a.zip

Brian
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AF6LJ

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Re: Q Meter Utilities
« Reply #1 on: February 26, 2020, 07:37:21 AM »

I've written some Windows utilities for the HP 4342A Q meter. They should be useful with other Q meters as well. They are particularly useful for measuring large coils at low frequencies.

If an inductance is too large to resonate with a Q meter's variable capacitor at the frequency of interest, you can add an auxiliary capacitor to achieve resonance. However, even if the Q of the auxiliary capacitor is very high, it can significantly alter indicated Q. For example, if you use a 3000 pF auxiliary capacitor with a Q of 3000 to augment a variable capacitance of 300 pF and the indicated Q is 600, the meter would read 733 if the auxiliary capacitor had no loss. All that's needed to correct indicated Q is the capacitance and Q of the auxiliary capacitor. You can use the Q meter to measure both. The utilities in this package perform the necessary calculations.

http://ham-radio.com/k6sti/hp4342a.zip

Brian
Thanks Brian for posting that.
My Q-Meter and I thank you.
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AF6LJ
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KI6R

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Re: Q Meter Utilities
« Reply #2 on: August 07, 2021, 08:23:44 AM »

Thanks Brian for some more good work with coil Q.  I have one of the HP meters (Eb Keller's old meter) and will be able to use your program.  73, Ed, KI6R
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