Add a cap across each voltage. If you are using a supply with voltage divider for "C" voltage and don't have caps there will coupling between the two.
Norm
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:The radio I'm working on a radio that takes a C battery with two C voltages, -1.5 and -7.5. By disconnecting the -7.5 and while holding the wire, motoboating stops and radio plays well, with output somewhat diminished.
:The radio I'm working on a radio that takes a C battery with two C voltages, -1.5 and -7.5. By disconnecting the -7.5 and while holding the wire, motoboating stops and radio plays well, with output somewhat diminished.
Turning volume way up probably causes voltage to go down a little? Do you hear the motorboating with volume turned down? If so problem is in the audio section.
Have you recapped the radio? Did you try adding caps across batteries? Distortion is often caused by leaky coupling caps in the audio section. This causes grid 1 of the audio tube to go positive.
Norm
:The motorboating now sounds more like morse code and not a uniform put put when on the station, which comes through garbled. By turning the volume way up it seems to affect the output. Is this problem in the RF section?
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::The radio I'm working on a radio that takes a C battery with two C voltages, -1.5 and -7.5. By disconnecting the -7.5 and while holding the wire, motoboating stops and radio plays well, with output somewhat diminished.