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49-602 Philco portable radio
4/11/2014 9:41:25 AMBob
I have recaped this radio. I have tested the tubes and replaced most with n.o.s. I have checked the 60 ohm resister. In short I have done everything I can think to do. The radio seams to have one tube lighting but I can't see any others. Any ideas would be appreciated as it makes no sound,and yes the audio transformer seems fine. Thanks for your time and imput.
4/11/2014 10:35:04 AMCV
You said that you tested "most" tubes. The Tube Corollary to Murphy's Law states that if you don't test all tubes in a set, the untested one(s) will surely be bad. :<)

Did the set work at all before it was overhauled?

These battery-operated sets don't generate much visible light from the tubes. You can check voltages at the heater pins to ensure that the tubes are actually being powered up.

Next, check plate voltages at each tube position per the schematic. Missing plate voltage can indicate an open transformer or open current-limiting resistor on the B+ bus.

If these two simple tests check out OK, I'd start at the audio output stage with a signal injector and work backwards toward the front end.

The possibility of creating a miswire is always present after a major recap job.



4/11/2014 10:36:17 AMCV
Ignore my "untested tube" comment. I misread your post.
4/11/2014 12:46:36 PMNorm Leal

Hi

Measure filament voltage on the 1R5 tube, pin #1 and #7. It should be around 1.4 volts. Too low and the tube won't operate.

Tap your 1U5 tube. This should cause a ping in the speaker.

Norm

: I have recaped this radio. I have tested the tubes and replaced most with n.o.s. I have checked the 60 ohm resister. In short I have done everything I can think to do. The radio seams to have one tube lighting but I can't see any others. Any ideas would be appreciated as it makes no sound,and yes the audio transformer seems fine. Thanks for your time and imput.
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