05-02-2017, 04:31 PM
You don't have to change all the tubes, but I would try installing the new 6K6 tubes and see how the voltage changes across R100. The voltage on 6K6 pin 3 will probably go down and the voltage across R100 up. I would guess to around 25 V across R100.
What pin of the 7AF7 has 300 V on it? I don't have the schematic of your radio so I can't follow.
What pin of the 7AF7 has 300 V on it? I don't have the schematic of your radio so I can't follow.