> On a tetrode (not with handles) working in class A
> what will happen if heater voltage and g1 voltage are
> removed at the same time and g2 and plate still would be
> there? At the time the tube would be in standby with class A
> bais current.
Current would get pretty high before the cathode cools off. It could
easily wipe out the tube or power supplies.
Bias should be the first thing on, and last thing off. That's why the
bias supply is best shunt regulated with a big capacitor and little
bleeder current, and the plate and screen supplies should operate
from a voltage sensor that detects grid bias.
With no bias, you must NEVER have anode or screen voltage.
73, Tom W8JI
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