Rich says:
>>There was no great difference between them at VHF, but at HF the
>>nichrome had much lower Q (as would be expected).
>>
>EUR Tom -- your theory that the resistance of nickel-chromium alloys
>Increases with a decrease in frequency is not supported by any published
>measurement.
Rich, you've lost me here. To me Q is (in this context) XL/r. Let's have r
constant with frequency; XL increases with frequency. Therefore the Q of an
inductor rises as the frequency goes up, doesn't it? And falls as the frequency
(i.e. XL) goes down.
Now if the material has a permeability other than 1, resistance will rise as the
frequency goes up, but Q will still drop as frequency goes down. Isn't this what
Tom said?
If you put a resistor across the nichrome inductor, then the value that Q can
reach is limited, and the parallel impedance is, in the limit, the value of
parallel resistance.
73
Peter G3RZP
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