10-29-2016, 09:05 AM
I have finished recapping this radio and am able to hear the local broadcast stations clearly but there is an annoying hum or put-putting in between the local stations. All the voltages on the tubes seem to be in line with what is on the schematic (here's the schematic LINK, ignore the red line highlights).
When I do the first step of the alignment procedure, i.e. modulated 455kc applied to the grid (pin 6) of the 1LC6 converter) with band switch at Broadcast and tuning dial at 60 I can hear the tone but there is also a motorboating sound that is louder than the tone. If I switch the Band Switch to any of the Shortwave bands, the motorboating goes away and I hear a nice clear tone. That should tell me something but I'm not quite sure what. There must be something amiss in the broadcast band portion of the circuit. (I've done the deoxit cleaning on the switch connections with no change.) Any thoughts?
When I do the first step of the alignment procedure, i.e. modulated 455kc applied to the grid (pin 6) of the 1LC6 converter) with band switch at Broadcast and tuning dial at 60 I can hear the tone but there is also a motorboating sound that is louder than the tone. If I switch the Band Switch to any of the Shortwave bands, the motorboating goes away and I hear a nice clear tone. That should tell me something but I'm not quite sure what. There must be something amiss in the broadcast band portion of the circuit. (I've done the deoxit cleaning on the switch connections with no change.) Any thoughts?
