09-28-2024, 12:20 PM
Hi philco4me,
So, your issue with the low volume after warmup could be a few things. One being what you suggested, weak tube. You can do 2 things to try and narrow it down. You can substitute the tubes one at a time, and I would start with the 14B6 detector. Or create a voltage chart of tube voltages right after power-on when the tubes are cool, should take just a few minutes. Then, when the volume decreases, read the voltages a second time. Keep in mind, if it's not a flaky tube, it could be a e sistor or capacitor changing value after having voltage applied. In either case you should see a change in voltage readings.
The other issue with the 5pf cap is more than likely a gimmick cap. That's two wires twisted together with one wire soldered to the tuning condenser, and the other wire connected to the loop antenna. You may have inadvertently removed them during your restoration. (What's up with these extra wires?) Hope this helps.
So, your issue with the low volume after warmup could be a few things. One being what you suggested, weak tube. You can do 2 things to try and narrow it down. You can substitute the tubes one at a time, and I would start with the 14B6 detector. Or create a voltage chart of tube voltages right after power-on when the tubes are cool, should take just a few minutes. Then, when the volume decreases, read the voltages a second time. Keep in mind, if it's not a flaky tube, it could be a e sistor or capacitor changing value after having voltage applied. In either case you should see a change in voltage readings.
The other issue with the 5pf cap is more than likely a gimmick cap. That's two wires twisted together with one wire soldered to the tuning condenser, and the other wire connected to the loop antenna. You may have inadvertently removed them during your restoration. (What's up with these extra wires?) Hope this helps.
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