Yah, miniman hit it with what I was looking for, the bias in the tube is pretty high....
Quote:
For the other example: .93ma@23kv=21 watts which is much better but
again, outside what I would consider normal for a shunt tube which should be
closer to .8ma. Obviously whenever you have something on screen, shunt
current should drop as the CRT beam current picks up where the regulator left
off. You should check to make sure the shunt tube's cathode current drops as
brightness increases, if not the regulator circuit is suspect. Also take a look at
your B+boost voltages, as that's where your regulator is taking its reference
voltage from. If B+boost is jacked, so will regulator cathode current as the
grid receives it's marching orders from whatever B+boost is doing.
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I was going to ask about those current readings, are they ma. and how accurate
do you think your meter is...?
Also that voltage I asked about B+ Boost, you did not post a number...?
You need to measure these things today, not look up your old posts, we need
to clarify exactly what is happening.... Your B+ Boost could be too high, this could
be why the voltages at the reg. are higher than the schematic says they should be...
.