Having read with interest the recent 8874 thread I am prompted to ask a
question that has been bugging me for a while.
My Alpha 78 with what I believe are 3 NOS 8874 tubes, 2 from one source
third from another does about 1500 watts out key down. Plate voltage
shows about 1800 at that time, about 2150 to 2200 off load. Grid current
runs about 80 to 90 mA but if I key up for a while then key down again
the grid current first registers just over 100mA and then over a period
of a few seconds drops back to about 80mA. Power out does not seem to
change.
Is it something getting hot? Drifting? Or is it just normal?
Thanks
Martin, HS0ZED
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