[Amps] SB-220 and 50Hz and more

[Vic Rosenthal]

W2RU - Bud Hippisley wrote:

> 3.  I operate 99% CW, and have added a 25 - 28 volt (50 watt!) Zener in
> series with the stock 5.1 volt operating bias Zener when I am on CW.  I
> originally did this because I run full break-in on CW, and use an electronic
> TR switch on the output of the amplifier, so I needed to cut off all plate
> current to eliminate "hash" in the receiver.  Secondary benefits of this are
> that I have no power dissipated in key-up idling current and my key-down
> efficiency is probably slightly higher than it would be with the stock class
> B biasing.  

I am also primarily a CW operator and would be interested in hearing about any 
others who have optimized amplifiers for CW.  I've always felt that it's a shame 
to waste power by biasing CW amplifiers for minimum IMD!

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco