08-23-2026, 09:11 PM
Hi Bob,
What happens if you turn the volume control down and back up slowly after losing sound? Do you have to turn the set off after the issue occurs before sound is restored? What does the tuning eye do? The tuning eye should NOT change when raising or lowering the volume. If it returns to normal until you reach a certain level, you may be saturating the Audio stage.
In addition, an intermittent speaker connection can cause this. the flexible braided wires between the speaker's voice coils and the terminals of the speaker experience much flexing and break. Resolder these.
In old days, turning the volume control high would saturate the RF Stage, as the Volume control controlled either antenna signal strength, RF stage bias or both. This happened often with older sets that did not have AVC but most superhets made 1934 or later, including yours have AVC, and the volume control merely controls signal level to the 1st Audio stage, and varying the volume control shouldn't change the gain of the RF, converter or IF stages, only the audio stage. This is why checking the tuning eye function can help determine if the problem is in the audio stages (likely) or in the RF, converter, IF and detector stages (unlikely). If there is no sound, and turning the tuning cap causes the tuning eye varies but no sound is generated, this can rule out the RF, converter, IF and detector stages.
There is a lot of resistance between the low end of the volume pot and ground, particularly in R14, a 470K resistor. This is quite a bit more than in other sets.
Verify the resistance of resistors R13 (the volume control), R 14 and Resistors R21, 22 and 23. Also verify the condition of capacitor C27. this capacitor may be metal cased to be shielded and you may not have changed it. If thi capacitor is leaky, increasing the volume could saturate the 1st AF tube. Saturation does not mean that maximum volume will be attained, saturation will "rail" the voltage output of the tube, there will be no variation, therefore no sound.
High resistance potentiometers are generally rated as either Linear taper or Audio taper. having a linear taper won't cause this issue but will cause difficulty in controlling volume, especially at low levels.
The trouble may be elsewhere, such as a bad 1st AF, bad output, bad speaker voice coil flex leads, etc. but start there.
Hope this helps!
What happens if you turn the volume control down and back up slowly after losing sound? Do you have to turn the set off after the issue occurs before sound is restored? What does the tuning eye do? The tuning eye should NOT change when raising or lowering the volume. If it returns to normal until you reach a certain level, you may be saturating the Audio stage.
In addition, an intermittent speaker connection can cause this. the flexible braided wires between the speaker's voice coils and the terminals of the speaker experience much flexing and break. Resolder these.
In old days, turning the volume control high would saturate the RF Stage, as the Volume control controlled either antenna signal strength, RF stage bias or both. This happened often with older sets that did not have AVC but most superhets made 1934 or later, including yours have AVC, and the volume control merely controls signal level to the 1st Audio stage, and varying the volume control shouldn't change the gain of the RF, converter or IF stages, only the audio stage. This is why checking the tuning eye function can help determine if the problem is in the audio stages (likely) or in the RF, converter, IF and detector stages (unlikely). If there is no sound, and turning the tuning cap causes the tuning eye varies but no sound is generated, this can rule out the RF, converter, IF and detector stages.
There is a lot of resistance between the low end of the volume pot and ground, particularly in R14, a 470K resistor. This is quite a bit more than in other sets.
Verify the resistance of resistors R13 (the volume control), R 14 and Resistors R21, 22 and 23. Also verify the condition of capacitor C27. this capacitor may be metal cased to be shielded and you may not have changed it. If thi capacitor is leaky, increasing the volume could saturate the 1st AF tube. Saturation does not mean that maximum volume will be attained, saturation will "rail" the voltage output of the tube, there will be no variation, therefore no sound.
High resistance potentiometers are generally rated as either Linear taper or Audio taper. having a linear taper won't cause this issue but will cause difficulty in controlling volume, especially at low levels.
The trouble may be elsewhere, such as a bad 1st AF, bad output, bad speaker voice coil flex leads, etc. but start there.
Hope this helps!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
Best Regards,
MrFixr55
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