Setchell Carlson...588 dial, 407 cab, 420 chassis(?) Serious need of a schematic.

[Reece]

Don't think you need to do the capacitor drop for the heater voltage, seems to be already taken care of. In the underchassis shot, underneath the 6Q7, I see what looks like a 50 ohm wirewound resistor. I did the calculations and that would be about right for dropping the heater voltage if you used 115V as the line voltage. For 120V line voltage you'd need 70 ohms. Although the calcs say smaller, I'd use a 20 watt for either ohms value for it to run cooler. Don't know what watts the present one is. The 50 ohm is probably OK but I'd measure voltage at the tube heater terminals to see how close it is to spec. I think I'd also move that resistor away from directly underneath the tube socket, towards the rear of the chassis, moving any wires in the way. That resistor will get hot.

The first thing you need to do to get the set working is for the audio section to work. If it's not working you'll never know if the IF and RF are since you can't hear them. Always start at the speaker and work backwards. We know the speaker works since you can hear hum. You can use the diagram you found around the 6Q7 and the two 25L6's and check your wiring.

With a two foot piece of insulated wire, bare the end of it and touch to the grids of the 25L6's, one after the other. Should hear hum. With the volume halfway up, should hear loud hum when touched to the center terminal of the volume control. Check the grid wire going to the top cap of the 6Q7 and see if it has continuity or shorting anywhere. Check all components in the audio section for wiring mistakes or bad components.