Hi,
Having just looked through the manual, the final anode voltage at the tube
should be 5.5KV.
Does the HV adjustment pre-set make any diffrence to the voltage when
adjusted.
Daniel.
Greetings, good to finaly hear from someone with some info!!
Checking my notes I have 5.3KV, so I am not to far off. I did adjust
the HV adjustment but did not note if HV went up, the HV whine did go
up in frequency from a 2KHz 5Khz whine...................surely its
not supposed to be in the audible range. Screen also is a tad
brighter.
Another clue is a very dark neon, which I replaced with a similar
sized one and brightness and whine goes up slightly. Not sure of the
purpose of the neon or if you know what type I would need to order but
I measure about 400 VDC from ground to one side of the neon with the .
047 500Vcap to ground, but the other side of the neon measures 222 VDC
with only a .05 100V cap to ground...............hmmmmm.
My first clue that seems to lead nowhere at the moment is the large
resistor in the power supply that connects to Q3 collector. Mine is
almost burnt, and its value can't be read but measures 9 ohms. This
resistor does not seem to get hot at all. Feeding into the resistor is
20V. From the emitter of Q3 is 6VDC and this only runs to CRT
horizontal, which seems fine.
The 12 volt regulator is putting out 12 volts.
The only other clue I have is the voltages indicated on the back of
the HV board +75 +250..........I have none of these, I have 176V ,
15V, 83V
All transistors have checked out ok, and all caps either replaced or
checked for value and leakage.
Any help is greatly appreciated! Got a scan handy?
Thanks,
Dave