01-02-2013, 10:28 PM
If radio has not been re-capped, do so. Recommend you do not turn it on again until this has been accomplished.
Since the 20 is a TRF receiver there are fewer things to check. One thing it could be is your output transformer (#29) . Check it for continuity from plate to plate of your 71 tubes. Do this with the speaker plugged in to the chassis.
Next check your SP-PPG interstage transformer secondary (#22). You should have continuity from grid to grid of your 71 tubes.
Another common issue the model 20s have is the antenna/volume control circuit. The volume control (#1) has two sections, one should measure 250 ohms, the other should be 5000 ohms.
Since the 20 is a TRF receiver there are fewer things to check. One thing it could be is your output transformer (#29) . Check it for continuity from plate to plate of your 71 tubes. Do this with the speaker plugged in to the chassis.
Next check your SP-PPG interstage transformer secondary (#22). You should have continuity from grid to grid of your 71 tubes.
Another common issue the model 20s have is the antenna/volume control circuit. The volume control (#1) has two sections, one should measure 250 ohms, the other should be 5000 ohms.