01-04-2009, 05:39 PM
Did you clean the volume control ? How about the tube sockets and tube pins. Did you clean them and re-tention the tube sockets to assure good contact? Did you get all the old wax and dust out of the chassis and wiring? This could be it. Did you replace all the coupling capacitors, especially in the audio section? Go over all your solder joints again with the soldering iron just to make sure you don't have a cold joint. Did you measure the resistors when you had the set apart? Anything more than 20% off should be replaced. Any sign of cracking or discoloration on resistor indicates it should be replaced. There is also the possibility of a gassy output tube, or a weak 1st audio/detector. If you have spares, swap them out and see if it makes a difference. Check your voltages on the 1st audio and output tubes, if your schematic shows them. I assume the speaker is in good condition, but you can check this out by connecting a known good one to the voice coil winding. As this is probably a hot chassis type, be carefull not to touch anything when it is plugged in. Anyway that's where I would start.
The pilot light is behaving normally. As the tubes begin to conduct after warming up, the pilot light will become brighter. At high volumes, the pilot light may "pulse" slightly with the sound.
You can upload the schematic to this site, and then we can all have a look.
If you are receiving a few stations, and the hum is gone, you are 90% there.
The pilot light is behaving normally. As the tubes begin to conduct after warming up, the pilot light will become brighter. At high volumes, the pilot light may "pulse" slightly with the sound.
You can upload the schematic to this site, and then we can all have a look.
If you are receiving a few stations, and the hum is gone, you are 90% there.