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40-180 electrical troubleshooting
#1

I’m currently working on my Philco 40-180 radio. I’m having an issue. No sound. Low hum from speaker. I keep smoking (60) resistor. My voltage across the (61) capacitor is 200VDC and the voltage across (58) capacitor is around 40VDC. Not sure what’s going on. I appreciate all the help this is my first radio and I only have a basic knowledge of electronics. Thank you


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#2

Greetings;
I would suggest checking for voltage on the plates of the audio output tubes, the output transformers in these sets are notorious for failing primary windings. It is also possible that you may have a shorted tone correction capacitor connected across that same audio output transformer, or possibly a very leaky bypass capacitor elsewhere loading down the plate voltage.
Regards
Arran
#3

You have a bad, bad tube or a short somewhere.
You should not just turn things on. Check for low resistance across 58, make sure it is not the 58 itself, and start looking for the bad part.
PS. Having started the thread, it makes sense mentioning if the recap has been done, tubes checked, etc.
We cannot say much until we know the basics.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#4

I replaced both 58 and 61 on the schematic. I noticed when I unplugged the speaker itself the resistor (60) 150om does not get hot. I went through and replaced any broken wires and any resistors that look bad or tested off. Not to sure I appreciate all the help I’m still new to this and only have a basic knowledge of any electrical work. Thanks again
#5

That's what we strive for here. First-timers to electronics gurus reside here. We just want to see an era maintained and remembered. Ask questions all you want. You can almost bet someone else dealt with a similar issue. Lots of help available. Take care and BE HEALTHY! Gary

"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan
#6

I isolated the circuit. And I’m still blowing 60 resistor. I just ordered the 84 rectifier tube. To see if that’s the issue. I already replaced both (58 and 62) capacitors. All the resistors are all replaced in this section of the circuit. How can you test the field coil and the transformer? If I take the 2 resistors off (59 and 60 My voltage is around 360vdc. I appreciate all the help thank




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