1950s or '60s vintage Zenith TVs, Need some info

[Kevin Kuehn]

Originally Posted by vortalexfan

I'm measuring a negative voltage at point TS8-3 and everything to the right of that in the TV's Audio Circuit, everything to the left of that measures normally (or as normally as a still malfunctioning TV can measure) which is the 210V that is supposed to be the 245V B+ Supply which is currently only measuring 210V right now.

How about you disconnect C50 and see if that negative voltage situation changes. I'm trying to get you to isolate one circuit from the other so we can make some progress and you're being very difficult to influence.

[vortalexfan]

Originally Posted by Kevin Kuehn

How about you disconnect C50 and see if that negative voltage situation changes. I'm trying to get you to isolate one circuit from the other so we can make some progress and you're being very difficult to influence.

I did disconnect it earlier and it did make somewhat of a difference but not a whole lot I wasn't getting negative voltages anymore but I was still getting only 22V on pins 5 and 6 of the 6AQ5 tube, so in that sense the removing C50 didn't affect the voltages but it did eliminate the weird negative voltage issue that was going on to the right of C50 in the audio circuit.

[Kevin Kuehn]

Originally Posted by vortalexfan

I did disconnect it earlier and it did make somewhat of a difference but not a whole lot I wasn't getting negative voltages anymore but I was still getting only 22V on pins 5 and 6 of the 6AQ5 tube, so in that sense the removing C50 didn't affect the voltages but it did eliminate the weird negative voltage issue that was going on to the right of C50 in the audio circuit.

Well for heavens sake please leave it out of the circuit if it eliminates the negative voltages. Unless you really enjoy banging your head on the wall. Then we can hone in on why the voltages are so low. Do you have a new capacitor you can replace C50 with?

[vortalexfan]

Originally Posted by Kevin Kuehn

Well for heavens sake please leave it out of the circuit if it eliminates the negative voltages. Unless you really enjoy banging your head on the wall. Then we can hone in on why the voltages are so low. Do you have a new capacitor you can replace C50 with?

No unfortunately I don't, but I have one on order from AES I ordered a 10,000pF 5kV ceramic disc cap from AES because the 5kV ceramic disc caps were the only ones that had the 10,000pF value without having to go into the polypropolene/Polystyrene/orange drop variety caps.

Anyways I'm very sorry I'm frustrating you, and believe me this is frustrating me just as much as it is you, because I was hoping that these Zenith TVs would just work after being recapped like my Meck TV did but unfortunately that's not the case here, these Zenith TVs are being stubborn and are not wanting to work correctly even after a recap job.

[Kevin Kuehn]

Originally Posted by vortalexfan

No unfortunately I don't, but I have one on order from AES I ordered a 10,000pF 5kV ceramic disc cap from AES because the 5kV ceramic disc caps were the only ones that had the 10,000pF value without having to go into the polypropolene/Polystyrene/orange drop variety caps.

I think 10,000 pf is the same as .01uf, no? At any rate that's what I'd put in there, or whatever you have that's close. It's an audio coupling cap so not that critical.

[vortalexfan]

Originally Posted by Kevin Kuehn

I think 10,000 pf is the same as .01uf, no? At any rate that's what I'd put in there, or whatever you have that's close. It's an audio coupling cap so not that critical.

Yes 10,000 pF is the same as .01 MFD but I'm not sure what the voltage is as it's not specified in the Sam's, plus the Sam's calls out specific types of caps by the value given (MFD for paper caps or film caps in the modern world, and mmfd for ceramic disc or mica caps.) I have some .01 MFD 630V film caps but I don't.know if the voltage is high enough, because I know a lot of times ceramic disc caps used in TVs were often times 1kV or higher rated.

[Kevin Kuehn]

Originally Posted by vortalexfan

Yes 10,000 pF is the same as .01 MFD but I'm not sure what the voltage is as it's not specified in the Sam's, plus the Sam's calls out specific types of caps by the value given (MFD for paper caps or film caps in the modern world, and mmfd for ceramic disc or mica caps.) I have some .01 MFD 630V film caps but I don't.know if the voltage is high enough, because I know a lot of times ceramic disc caps used in TVs were often times 1kV or higher rated.

.01 MFD 630V film is fine. We know what the B+ is supposed to be on the detector side, and there should be no B+ on the volume control side.