Hi everyone.......I'm trying to get this radio working but haven't had much success. I have gotten rid of the hum but still have boatmotoring. The beat is real fast at low volume but decreases to a slow putt,putt at high volume. I have replaced the electrolytic caps plus others.....any ideas for me.

Thanks

Hi Job

Motorboating is usually caused by caps or lack of tube shielding. Don't think your radio uses any tube shields?

See if any capacitors are missing or connected to the wrong place. When replacing C401 you can leave out the coil shown on the schematic.

http://www.nostalgiaair.org/PagesByModel/599/M0013599.pdf

Norm

:Hi everyone.......I'm trying to get this radio working but haven't had much success. I have gotten rid of the hum but still have boatmotoring. The beat is real fast at low volume but decreases to a slow putt,putt at high volume. I have replaced the electrolytic caps plus others.....any ideas for me.
:
:Thanks

::.... I have replaced the electrolytic caps plus others.....any ideas for me.
::
::Thanks

Be sure you replaced C203, C202, C201,C200 and the AVC buss filter C302. Also be sure all the resistors in the audio section are still in tolerance; R200, 201, 203, 204, 205.

Chuck

......and make sure that none of the speaker wires are anywhere near the 1s audio tube or its related components.