Thanks to all those who have replied direct
and also privately. I did find a resistor
on the anode clip had one lead snapped. I
am not sure whether it was like that or if
it happened while i was removing a tube.
Regardless, i did the "tube-swap-a-rama"
tests and came up with these results:
SOCKETS: L R Pout
==============================
Tube(s) L R 400w
Tube(s) - R 200w
Tube(s) L - 250w
Tube(s) R - 170w
Tube(s) - L 270w
I also put a tuner between the rig and
the amp. SWR was 1.5:1 but when i enabled
the tuner i was able to get a little
more power...
20m: plate current = 325 mA, HV=1900.. so P=617.5
and with 50% effeciency that would be ~309w. I
am seeing just under 400w so is the effeciency of
this amp higher? 350w no tuner, 390 with tuner.
40m: plate current = 320mA HV=1900.. so P=608
or 304 watts (@ 50%). I'm seeing: 375 w (no
tuner) and 410 with tuner.
Could the tubes be "OK" but "going bad" or do
you see an indication of something else here?
For 1200w input (600w output) shouldn't i be
seeing 600+ mA? (1200w/1900 HV = 631mA). I'm
seeing only around 320 to 325 mA when running
with both tubes, and its my understanding that
the meter should show the total current not
per tube. Right?
One thing i notice is that any single tube,
when it is in the right socket, puts out
more power than when it is in the left socket.
Thanks for any comments...
Steve, N9OH
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