05-08-2026, 08:09 AM
Hi Arran
I think I may have figured out the dial cord. In the process the very brittle plastic dial was cracked and broke into 3 pieces. Another set back!
The PP audio stage has original C-183 power output tubes, which are working great.
Changing the subject to the volume control. The volume control circuit of this radio appears to be modified. I believe the control was initially a 2-gand pot. The pot in this radio is a single gang but is very high in resistance. I opened it up and the resistive strip is basically open.
The radio appears to be modified. There is a 200 ohm fixed resistor installed on the first RF tube cathode to ground. The volume control is a single gang pot and had been wired to control the screen voltage of the first and second RF tubes. Also, there is no control on the antenna circuit as shown on the schematic. Do you know if this was a production modification? The original on/off switch is failed. It is a unique arrangement in that there is a cam on the rear of the volume control shaft that actuates an independent toggle switch. I have been trying to source a 2-gang potentiometer (50k & 30k) with an integral on/off switch. It would be ideal if I could find an original volume control. Or???
I think I may have figured out the dial cord. In the process the very brittle plastic dial was cracked and broke into 3 pieces. Another set back!
The PP audio stage has original C-183 power output tubes, which are working great.
Changing the subject to the volume control. The volume control circuit of this radio appears to be modified. I believe the control was initially a 2-gand pot. The pot in this radio is a single gang but is very high in resistance. I opened it up and the resistive strip is basically open.
The radio appears to be modified. There is a 200 ohm fixed resistor installed on the first RF tube cathode to ground. The volume control is a single gang pot and had been wired to control the screen voltage of the first and second RF tubes. Also, there is no control on the antenna circuit as shown on the schematic. Do you know if this was a production modification? The original on/off switch is failed. It is a unique arrangement in that there is a cam on the rear of the volume control shaft that actuates an independent toggle switch. I have been trying to source a 2-gang potentiometer (50k & 30k) with an integral on/off switch. It would be ideal if I could find an original volume control. Or???
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