Re: D-104 preamp ...
Posted by
George & Jan on
Jul 21, 2010; 6:49pm
URL: http://elecraft.85.s1.nabble.com/D-104-preamp-tp5319528p5322362.html
Joe,
If you aren't married to the original element you could change it out to an
electret element wired directly to the K3 input with the bias turned on. I
did that than trying to find a replacement crystal element.
The electret element is available from many sources (including your local
Radio Shack) for a couple of dollars. Make sure to get the 2 wire version.
Otherwise you could create a "phantom" voltage source in the D104 using a
blocking capacitor on the FET output and a diode to a pad-out resistor and
filter capacitor.
I get good reports on audio quality on my electret but suspect it is the K3
not the microphone!
George
AI4VZ
---------------
That circuit won't work with the K3's bias on mic pin (Joe's intended use).
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