Hello All
The TL922 manual says "DO NOT under any circumstance OPERATE your exciter in
CW mode when the linear is in the SSB mode. Failure to head this warning may
cause immediate, extensive damage to the amplifier""
"REPEAT: DO NOT OPERATE CW IN THE SSB MODE"
I always wondered about this comment. The amp runs in CW mode at about
1700V and about 2700V on SSB (Under load). On CW, the amp barely puts out
as much power as my single tube AL80A. The statement above is remarkably
emphatic but I wonder how accurate it really is when the SSB tune up
procedure allows key down in SSB mode.
My question is what is the weak link that prevents operating CW at the
higher voltage and is there a mod to get around this?
As long as I am asking questions, the AL80A manual says to tune up to 550 mA
of Ip and then back off to 400. I think the 3-500Z max Ip is 400 mA. Is it
really OK to drive it at 550 mA? If so, is the amplifier still linear at
this level? Is 400 mA the destructive limit or is it the point at which
tube aging will accelerate? Also, in a grounded grid configuration like
the AL80, at what current would linearity be lost? Is there a reference
with the appropriate curves that I can use to answer this question?
Thanks in advance
Tom W2SC
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