Old Muntz TV for sale Locally to me, Should I pick it up?

[Electronic M]

If you pull the vertical output tube too and it still draws close to rated power (as I suspect it will) you still need to finish troubleshooting the power supply...Like I said the social coil circuit could be an issue...also depending on where that 390 ohm resistor is in circuit whatever is causing it to smoke is also a likely cause of the overload.

[Kevin Kuehn]

Originally Posted by Electronic M

If you pull the vertical output tube too and it still draws close to rated power (as I suspect it will) you still need to finish troubleshooting the power supply...Like I said the social coil circuit could be an issue...also depending on where that 390 ohm resistor is in circuit whatever is causing it to smoke is also a likely cause of the overload.

social coil circuit?

R62(390 ohm) is the plate load resistor for the 6V6 audio out(Sams calls it a filter). It supplies voltage from the wiper of the focus coil to the 6V6 plate circuit. This set uses the audio output stage as a voltage dropper, similar to Admiral sets of the time. It's plate voltage(pin 3) should be 205vdc referenced from the cathode(pin 8). Confusing as all get-out to troubleshoot. As mentioned above, best to follow Sams voltage measurement chart to isolate the problem area.

[Electronic M]

Originally Posted by Kevin Kuehn

social coil circuit?

R62(390 ohm) is the plate load resistor for the 6V6 audio out(Sams calls it a filter). It supplies voltage from the wiper of the focus coil to the 6V6 plate circuit. This set uses the audio output stage as a voltage dropper, similar to Admiral sets of the time. It's plate voltage(pin 3) should be 205vdc referenced from the cathode(pin 8). Confusing as all get-out to troubleshoot. As mentioned above, best to follow Sams voltage measurement chart to isolate the problem area.

Focus coil.

My smart-ass-phone has an overly aggressive autocorrect baked into it's typing utility and it likes to substitute different words for correctly spelled ones when it thinks I didn't use the right one in sentence context...it drives me nuts sometimes, and is even worse for brand name that were gone before my generation and TV service lingo that is otherwise dead.
There are also times it will botch a word in messages to friends and I'll retype the word to make it make sense and it will change it when I push send.... infuriating.

[vortalexfan]

Originally Posted by Electronic M

My smart-ass-phone has an overly aggressive autocorrect baked into it's typing utility and it likes to substitute different words for correctly spelled ones when it thinks I didn't use the right one in sentence context...it drives me nuts sometimes, and is even worse for brand name that were gone before my generation and TV service lingo that is otherwise dead.
There are also times it will botch a word in messages to friends and I'll retype the word to make it make sense and it will change it when I push send.... infuriating.

I also have issues with spell checker on my phone, although not nearly as bad as yours, and I agree it's infuriating.

I'll take a look at some more voltages.

[vortalexfan]

OK so this is weird but going across pins 3 and 6 on the 6T8 tube on the TV there is a 30 Ohm dogbone resistor that doesn't show up anywhere on the sams and it measures open which might be part of the reason why this TV has no audio as the 6T8 in this TV functions as the Phase Inverter for the 6V6 tube as well as the Audio Frequency Amplifier and the Ratio Detector Tube, and that dog bone resistor looks factory (which I know sometimes there were little changes made to these old electronics at the factory that weren't always put into the sams because they were done after the Sams were made.)

The other resistors on the 6T8 Tube which goes across pins 2 and 6 (which are the plates of the tube) measure nearly spot on.

so that open 30 Ohm dog bone resistor might be part of the reason why I have no audio.

As for the voltage and resistance readings on the tube sockets, the resistance readings on the 5U4 tube are are a little high, pins 2 and 8 which should measure around 22k ohms measures around 32k ohms and then pins 4 and 6 should measure around 68 Ohms but instead measure around 72 ohms.

That measurement was taken without the tube in the socket and the set powered off.

[Kevin Kuehn]

Don't worry about the 6T8, it has no bearing on your power supply issue and in fact you can remove it from it's socket if it's bothering you. So did you measure the voltages on the 6V6 audio output tube?

[vortalexfan]

Originally Posted by Kevin Kuehn

Don't worry about the 6T8, it has no bearing on your power supply issue and in fact you can remove it from it's socket if it's bothering you. So did you measure the voltages on the 6V6 audio output tube?

No, I didn't yet.

But I did figure out that pretty much all the resistors in the audio circuit that are associated with the 6V6 and the 6T8 tube are all measuring bad (either way high or open), also the 6,000 ohm 10% 20 Watt wirewound resistor that's part of the HV section is measuring open as well in the Sams its called the Damper Filter-Wirewound, which might be why I'm not getting any HV and also might be part of what's causing the TV to motorboat.