Hello,
I own a centurion PA, wich caused and causes
some troubles to me.
Since I own it, I lost 2 3-500Z tubes, without
transmitting more than 5 minutes, nobody here could
say me the possible reason, as if everything measured
seems to be ok.
They all were shortend and the "plate ampere'-Meter
went to the left....
Now I have the 3rd tube and it works well so far. It
always was the same socket, where the tubes died,
but - as I said - they are in parallel and everything
seems to be ok, the new tube always worked a little
time,hi.
I also made the modification, so that the tubes are
not biased in operate-mode without keying.
I own a copy of a modification, mainly on the filament-AC
board.
That worked so far, no current was flowing in operate--mode.
Now it is again the same thing as original (Approx. 100ma),
the 3 components, which were installed are still ok and all the
contacts to (I soldered it again)!
(MPS-U01 Trasnsitor, 1k 1/4w resistor and a 5W
zener diode).
Has anybody any idea for a solution?
Is it normal, that the tubes became really hot without to much
power (around 400w maximum)?
(Yes I am not an electrician,hi).
73 de Guenther/OE2LCM
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