6U5/6G5 Tuning Eye Tube Questions

[Captainclock]

Originally Posted by jr_tech

Max plate (pin 2 through 1 meg resistor) and target (pin 4) are listed at 250 volts, although it may have been fairly common practice to push that spec a bit to obtain higher brightness, at the expense of life of the tube.

jr

data sheet: http://www.r-type.org/pdfs/6e5.pdf

OK so how do I go about testing to see if the plate voltage for the tube socket is up to par or not? Should I just remove the tube from the socket and then stick my DMM probes into the right holes for the tube pins to go into and then get a measurement from ground?

So If I were to get a lower plate voltage reading than the specified 250 Volts then what should I look for component wise that could be causing the low plate voltage?

Update: I measured Pin 2 and got a little over 200 Volts (around 208 Volts DC) and at pin 4 I got around 248 Volts DC, So I'm not sure what to make of those results but I'm guessing that both pins 2 and 4 are supposed to measure around ~250 VDC? If so then that means pin 2 isn't getting the proper voltage it needs for some reason which is why the tuning eye tube is dim.