A friend of mine gave me an old homebrew 4 x 811 amp that I have been
playing around with for the last few weeks. At first the amplifier would
work, but now, it keeps blowing one of the grid leak bias resistors
(51 ohms). The failure occurs when I turn on the high voltage (+1600 VDC).
At this point the amplifier is in its standby mode with the grid biased to
cutoff at -170 volts. Looks like one of the tubes has gone gassy and is
flashing the anode supply over to ground the grid leak resistor.
Anyway, looks like I will need at least one additional tube. Can anyone
recommend a good source/reasonable price?
Thanks,
Mike,
W4EF......................................................................................
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