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38-116 Code 125 Tube Heater Circuit Issue
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I'm still troubleshooting garbled audio on my 38-116 that I've recapped and replaced out-of-tolerance resistors.  I've been checking tube voltages and find that they are significantly low.  The lowest measurement was on the 6J5G driver tube.  I measured 48 vdc on it's plate instead of the specified 260 vdc.  I tried another 6J5 tube and got the same result.  I started checking heater circuit pins 2 and 7 on various tubes.  I found 6.3 vac on pin 7 but 0 on pin 2.  I checked the volts out of the transformer on the two black wires for the heater circuit and found that the output of the transformer for pin 2 was 0.  I assume the problem is in the power transformer.  But, I wonder why the wiring from the transformer for 6L6G pin 7 would first go to a chassis ground terminal on the bakelite block.  Shouldn't it just go direct to pin 7?  Note: Dial lamps work normally.

Thanks,
Larry


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38-116 Code 125 Tube Heater Circuit Issue - by LarryFS - 09-20-2019, 05:45 PM



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