Reply To: Dial Lamp and 35W4 circuit on Electrohome Roland 6T8 AA6 tube radio…

[Doug Parker]

John and Ralph. Thank you for your input. The R15 – 33 ohm 1/2 watt resistor is factory installed in my chassis from pin 5 (plate-anode of the 35W4) to the pin 6 and one side of the lamp just as the schematic shows. Obvious there was two different schematics for the same radio. The untouched chassis had the two (50 ufd – 150 volt) filter capacitor sections. I would agree that the R15 is used to limit the current flow through the 35W5 as it is in series with the anode to the rest of the circuit. I measured the voltage drop across R 15 when there was no signal applied and the voltage drop across the resistor was almost 1 volt. That works out to 3 milliamps approximately. The voltage at pin 7 of the 35W4 was 94 volts DC and the line voltage was measured at 120 VAC. I swapped in another 35W4 I had and the voltages were the same. I will install the chassis back into the radio as everything was working properly. Again, Thank you.