Quote:
Originally Posted by Crist Rigott
Another thought just occurred to me. When I was doing the voltage checks, the tubes were installed. Could the 350 volt marking on the schematic meant with the tubes removed? Though I don't see how you can get some voltages without them being installed. Just thinking out loud.
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Well, if the 12AX4 were removed, you wouldn't have any voltage on pin 3 (cathode) because it would break the DC current pathway for B+ to the rest of the H.sweep circuit. (Besides, with the tube removed, the other tubes won't light because it's a series heater string.)
The 350V is the raw,
unfiltered B Boost voltage, and you sure as heck don't want to measure it at the damper cathode (!). If the kit maker actually measured it there, they were using a beefy old analog meter with mechanical movement that smoothed out the high level spike. And they were highly negligent in not posting a hazard warning.