When measuring tube plate voltage should I measure between the plate and cathode or plate and ground? Also, I assume readings are much higher at the plate pins with the tubes in vs. out. I formed my caps and cranked up my clone today (tubes out) for the first time just to check the PS. It seems to be working as expected. I get readings from 503 at the power section progressing downward to 460 at V1 measured to ground. I have a few more parts coming in soon to complete the build and will put the tubes in at that point.
Thanks,
whit
Measuring plate voltage?
Moderators: pompeiisneaks, Colossal
Re: Measuring plate voltage?
Measure between plate and ground. The difference between plate and cathode should only be a few mv different so it doesn't matter much. I like to clamp the black lead to the chassis ground so I can work with one hand for safety.
Your plate voltages should be very close across all the tubes since there's no current draw with no tubes. If you're getting a drop you must have the 150K FET resistor in place drawing a little current.
So far your voltages sound about right. The real test is of course when you get the tubes in.
Your plate voltages should be very close across all the tubes since there's no current draw with no tubes. If you're getting a drop you must have the 150K FET resistor in place drawing a little current.
So far your voltages sound about right. The real test is of course when you get the tubes in.