[AMPS] PA Recommendation Wanted

[km1h@juno.com]

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

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm