"I'm wondering what the effect would be (linearity,
distortion, etc) of running the screen at a different
value than recommended in either/any class/mode of
operation. I'll probably be experimenting with
different values but wonder what the expert's thoughts
were."
Very few tubes have published screen voltage curves showing what happens
when you change screen voltage on a particular tube. The reason may be that
very few tubes are designed to have infinite screen voltage change.
The very few curves that are published lead me to conclude that varying
screen voltage within a range of 25% to 100% of maximum will be fine, with
the understanding that gain will increase as screen voltage is increased.
When the screen voltage is run below 10% of rated maximum voltage, strange
things can happen. I would be very concerned about distortion products and
other undesireable characteristics under those conditions.
And, be sure to use a regulated screen voltage.
73, Colin K7FM
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