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Thanks Tom, good timing as I just received the HV Probe that I have ordered recently. what I have found is not exactly what in the Sam's but not too far to indicate obvious problem, and here are what Sam's call for and what I have found (this when the contrast and brightness at minimum):
Cathode Grid 1. Grid 2
Sam's 2.7v 130v 240v
Actual 3.3v 136v 261v
the HV under these conditions is 8,900 v which is what the tube data sheet recommends, now when I crank the brightness to the maximum to get something on the screen the first grid voltage goes down to 8.6 v which seems correct but the HV drops down to about 6,700 v with about 700 v drop on the HV 1 M. Ohm filter resistor, indicating about 0.7 mA high voltage current. not sure if that is normal or not.
Other things I did, I tested all the tubes and in spite that they all tested good I swapped them all and rerun the voltage measurement but did not see any significant changes, in addition I checked all the components in the focus circuit including the focus coil and all seems to be fine.
Last edited by soliman15; 03-19-2021 at 10:36 AM.
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