Hello,
I replaced all paper and electrolytic caps in this radio and it plays and receives well, but after checking voltages, I have a question on the cathode of (pin 5 to chassis) 6ac7 (this is the 2nd IF of fm). I have +90 vdc on am and +3.2 vdc on fm on this pin. Manual says I should have +8 volts. I also have checked and replaced most resistors and other voltages look pretty close.Thanks,
Paul

Hi Paul

Cathode voltage is controlled by cathode resistor and emission of the tube. Your reading seems about right.

During AM one end of the cathode resistor is disconnected so voltage will be high. Tube is not used on AM.

http://www.nostalgiaair.org/PagesByModel/630/M0021630.pdf

Norm

:Hello,
:I replaced all paper and electrolytic caps in this radio and it plays and receives well, but after checking voltages, I have a question on the cathode of (pin 5 to chassis) 6ac7 (this is the 2nd IF of fm). I have +90 vdc on am and +3.2 vdc on fm on this pin. Manual says I should have +8 volts. I also have checked and replaced most resistors and other voltages look pretty close.Thanks,
: Paul
:

:Hi Paul
:
: Cathode voltage is controlled by cathode resistor and emission of the tube. Your reading seems about right.
:
: During AM one end of the cathode resistor is disconnected so voltage will be high. Tube is not used on AM.

Thanks, Norm I really appreciate your advise. Paul
:
: http://www.nostalgiaair.org/PagesByModel/630/M0021630.pdf
:
:Norm
:
::Hello,
::I replaced all paper and electrolytic caps in this radio and it plays and receives well, but after checking voltages, I have a question on the cathode of (pin 5 to chassis) 6ac7 (this is the 2nd IF of fm). I have +90 vdc on am and +3.2 vdc on fm on this pin. Manual says I should have +8 volts. I also have checked and replaced most resistors and other voltages look pretty close.Thanks,
:: Paul
::
:
: