Have an RCA Radiola 17 that sounds extremely distorted. I have played radio both through the RCA 100A Speaker designed for this set and modern 8 Ohm Speaker using an appropriate output transformer. Hum is acceptable (Power Supply was recapped, tapped resistor replaced)but distortion is unbearable, especially with music. Injecting an audio signal from a modern FM Radio into the 1st AF Amp yields a clean sound. Voltages on the UX 27 Grid leak detector appear normal (Plate voltage aprox 45V, cathode voltage aprox 9V . I have replaced grid cap (220pF, grid leak resistor 2MOhm and plate bypass cap (0.01uf) to no avail. Any ideas would be appreciated.

Best Regards,

John

Check the 1K grid stopper resistors.

Is the distortion on just the strong broadcast stations or all of them? If just the strong ones, I would suspect overloading of the RF stages due to signals jumping directly into the RF stages. If that's it there is a fix.

:Hi Doug,
Thanks for your reply. The issue occurrs on all stations, strong and weak, with and without an antenna. I have checked all the 1K Grid resistors in the RF stage and even attempted to connect the antenna to each RF stage and the detector stage. The distortion seems to occur around the detector. I have tried 3 different 27s, one NIB to no avail.

:
:Is the distortion on just the strong broadcast stations or all of them? If just the strong ones, I would suspect overloading of the RF stages due to signals jumping directly into the RF stages. If that's it there is a fix.
:

Is there any chance that the bias voltage for the detector has the wrong polarity?

Hi Doug, Sorry, lost router, finally got connection for my PC. It appears that I do have whay I think is the correct (?) bias of -9V, judging by the 2 schematics I found in this website.

:Is there any chance that the bias voltage for the detector has the wrong polarity?
:

Hi

Any chance secondary of one audio interstage transformer is open? Sometimes radios still operate with this winding open but distorted.

Be sure 1st audio amp and output tubes have correct bias.

Norm

:Hi Doug, Sorry, lost router, finally got connection for my PC. It appears that I do have whay I think is the correct (?) bias of -9V, judging by the 2 schematics I found in this website.
:
::Is there any chance that the bias voltage for the detector has the wrong polarity?
::
: