[Milsurplus] AN/GRC-9

[Richard Brunner]

wf2u at starband.net wrote:
.... They also had the French-made AM-66/GRC-9 100 W
> amplifier, which I didn't buy at the time, as I wanted a US-issued and not
> NATO specific setup. Too bad, because there are no AM-66 amps anywhere
> except in Europe now. I wonder who bought them up from Fair.

Have no regrets.  I had one and gladly sold it.  It uses three 2E22's in 
parallel at 700 volts, suppressor modulated for AM, and has several 
inexcusable serious design flaws.  When you switch from CW to AM the 
output goes down maybe 10% instead of 75% because the suppressor voltage 
for AM is much too high, -40 volts (same as the GRC-9) instead of about 
-100 volts.  The resulting modulation is mostly downward, but doesn't 
sound too bad in a receiver. I also believe biasing in the modulator was 
strange.  There is also significant attenuation of signals through the 
amplifier to the receiver.  I think they knowingly did all that to meet 
design criteria, engineering be damned.

Richard Brunner, AA1P