[laipplyken]

Hi Ken and welcome!
Remove the 80 tube and measure the AC voltage from pin 2 to pin 3. These are the two smaller pins on the socket. Be careful as if it's working you will see about 600-700vac there. Set must be on to measure the ac voltage.

Terry

I did as you said and got 757vac on 80 tubes smaller pins. I  also tested with the tube in and got 740vac from the two smaller pins (P-P). I was looking at the chart and it says 350vac from p-k. I was assuming they meant p-p however seeing the results I was wondering if they meant a different reading?

Ken