Date: Mon, 11 Jan 2016 10:16:58 -0800
From: "Charlie" <charlie@drhabekost.com>
To: <amps@contesting.com>
Subject: [Amps] Need for bias switch (CW/SSB)
Folks-
I am putting a 8877 amp together. I was wondering why some amps have a
"CW/SSB" switch.
Assuming the power supply can handle cw key down, other than higher
efficiency, what other reason could there be for this switch?
Thanks!
Charlie N6CFH
## For CW use, there is no need to use high amounts of idle current..on a
gg triode amp.
10-20 ma is ample for cw use. which will require more bias V... hence the
switch. Just use
a string of 1N5408s or 6A10s.... like 14-18 of em.
## back in the old days the cw /ssb switch changed the B+. This was for the
1 kw /2 kw pep
rules, when amps rated in input power. for low power 600w output cw /ssb,
eff is btter when using
a lower B+. Then the plate load Z stays the same.
Jim VE7Rf
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