OK, more on the A-1015-G preamp problems.
After further study of the circuitry, I determined that I was looking at
the preamp FET backwards. I had the drain and gates reversed. So I do
see DC voltage on the drain when the preamp is switched on - about 3.7
volts. The gate is effectively DC grounded by a choke. So the FET is
running with 0 gate bias.
Someone suggested that I may have a bad FET. While that's possible, it
appears the DC voltages I see are correct. And when I have the amp in
line and turn the preamp on, the noise floor rises significantly. I can
literally hear this on my transveiver. I wouldn't expect a bad FET to do
this.
Is it the FET or could there be other problems.
73,
Jon
KE9NA
-------------------------------------
Jon Ogden
KE9NA
http://www.qsl.net/ke9na <--- CHECK IT OUT! It's been updated!!!!!
"A life lived in fear is a life half lived."
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