On Fri, 6 Jun 97 09:46:10 -0700 Rich Measures <measures@vc.net> writes:
>>... ...Besides those 4CX800 tubes are in AB1 and require constant ALC
>
>attention.
>>
>I built and use an 8169 Class AB1 grid-driven amplifier. (to my great
>
>regret and embarrassment, alas, this tetrode does NOT have handles)
>An
>ALC circuit would be as useless as the teats on a boar hog because I
>made
>the 8169's grid bias V adjustable. Long, long ago I set the bias V
>adjusment so that my TS-440S could not produce grid current. I have
>not
>re-adjusted the bias V in at least a year. As I recall, the bias V
>is
>set to about neg. 240v. When I switch to a different anode supply V,
>I
>set the ZSAC to 0.4A with the screen V adjust, as Eimac recommends.
>Rich---
Well Rich, we cant all run tubes with handles or buy that poison ice
cream from Vermont.
Ya gotta remember that the average amp "OWNER" does not have a clue to
what he is doing....much less how to match his radio to his amp.
On VHF/UHF it is even worse with clowns running 4CX250's at 2500V and
nary a thought about bias or screen voltage stability, impedence, etc. At
least on HF the band noise covers most of that crud....on VHF we are not
so lucky.
73....Carl KM1H
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