I have an RCA 45 record player/radio Model 9Y51 and it has hum on the radio. No hum with the volume turned down to zero. There is station sound but lots of hum in the background. Have tried tubes and recapped except for micas. Help!

If there is no hum in the phono position it could be an open in the antenna return line circuit. Check the loop antenna continuity and its connections. Also check chassis ground points with the schematic.

:If there is no hum in the phono position it could be an open in the antenna return line circuit. Check the loop antenna continuity and its connections. Also check chassis ground points with the schematic.
:
It does the same thing in the phono position.

John

This radio uses shielded wire in the audio section. Be sure someone hasn't replace it with regular wire. Very important to have shields grounded

http://www.nostalgiaair.org/PagesByModel/396/M0015396.pdf

Norm

:I have an RCA 45 record player/radio Model 9Y51 and it has hum on the radio. No hum with the volume turned down to zero. There is station sound but lots of hum in the background. Have tried tubes and recapped except for micas. Help!
:

:John
:
: This radio uses shielded wire in the audio section. Be sure someone hasn't replace it with regular wire. Very important to have shields grounded
:
:http://www.nostalgiaair.org/PagesByModel/396/M0015396.pdf
:
:Norm

Yes, I see several shielded wires in the audio and all seem to be fine and original. Also, getting hum whenever I touch the chassis.
:
::I have an RCA 45 record player/radio Model 9Y51 and it has hum on the radio. No hum with the volume turned down to zero. There is station sound but lots of hum in the background. Have tried tubes and recapped except for micas. Help!
::
:
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I got it running but don't know how. I was checking around the volume control and noticed it was wired different than the schematic, however, did not look like it had been changed by anyone. One end of the control went through a 2.2M resistor to a standoff and then through a 1.5M resistor to the tap. Schematic shows 400K. I put the 2.2M directly to the tap bypassing the 1.5M and it works great and doesn't hum at all even when I touch the chassis.

::John
::
:: This radio uses shielded wire in the audio section. Be sure someone hasn't replace it with regular wire. Very important to have shields grounded
::
::http://www.nostalgiaair.org/PagesByModel/396/M0015396.pdf
::
::Norm

:
:Yes, I see several shielded wires in the audio and all seem to be fine and original. Also, getting hum whenever I touch the chassis.
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:::I have an RCA 45 record player/radio Model 9Y51 and it has hum on the radio. No hum with the volume turned down to zero. There is station sound but lots of hum in the background. Have tried tubes and recapped except for micas. Help!
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