I've built a few amplifiers over the years, but only one using Zener
diode bias. This is the most recent one: 8877 for six meters.
I built it "cookbook" style, following a couple of different plans
published in CQ. I used a 14 volt Zener. The amp appears to work well,
and according to reports sounds good.
My only problem, if it's a problem, is that the efficiency appears to be
low: 55%, if I can believe the meters.
Would a different value of Zener have any effect on efficiency?
The grid current runs lower than published figures at full output. The
resting plate current is about 100ma.
I can pull 1.2 amps at 4000 volts with 90 watts drive. Again, if I can
believe the meters.
I'm using, for the first time, a floating B-.
Any help with this would be appreciated.
Barrie, W7ALW
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