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  #61  
Old 03-02-2010, 07:21 AM
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You might plug it into your light bulb tester just for a quick check but otherwise you should be good to plug the tubes in and fire it up. The voltages will be a little higher than shown on the schematic since those windings are not being loaded down by the tubes.
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  #62  
Old 03-02-2010, 04:21 PM
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Ok, here's my story...

I plugged everything in including the 5y3 (aka 5z4) and the speaker. I powered up and heard some speaker static and a hum. My bulb tester went up, and I turned it all off. I pulled the 5z4 and the speaker because I knew everything else had seemed to be OK before. I turned my bulb tester back on and it looked like the radio switch was on. When I turned the radio switch off, it was off. Whether the switch was on or off the radio was still on. I pulled everything and I removed the on/off/tone switch which was one of the things I didn't fool with during the cleaning. When I opened it up, it was full of all kinds of old oils, dirt and whatnot; it was a mess. Some of the wires were loose or broken, but anyway, I took it all apart, dumped it all in denatured alcohol for a while, cleaned it and put on some nice new wires. I put it all back together again including the speaker and the short was gone; the switch worked very well. But now, no sound. I don't see any radiation coming from the 5z4 though there is a little heat at touch but not much. I took out the 5z4 and removed the speaker and everything is the way it was yesterday with nice glows from the tubes and no shorts showing on the bulb.

Can any of you make anything out of this or give me a little direction? I'm kind of stumped again.

Thanks!!!
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  #63  
Old 03-02-2010, 05:52 PM
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The 5Y3 should have 5 volts across it's filament (pins 2 & 8). Have you tried measuring that ?
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  #64  
Old 03-02-2010, 06:23 PM
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Yep.. back at post 60 I wrote down the 4 points. It is sowing 7.9V.
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  #65  
Old 03-02-2010, 06:29 PM
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So you did. Is that with the 5Y3 installed? If so, that's pretty high and you should check your tube for filament continuity.
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  #66  
Old 03-02-2010, 06:46 PM
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The rectifier filaments may read high until you have a current draw going. The power supply for my GE 802 was the same-I was getting 8 volts at idle on the filament string, and then back to 5v when it was running the set.

Tell us the plate voltage of say, pin 3 on the 6f6. It should be at least a couple hundred volts. Tell us if you have any voltage on c14 (your 10 mfd electrolytic capacitor) on the positive end of the cap versus the chassis. If you are getting voltage at that lytic but not at the 6f6, then you may have a problem with the field coil in your speaker.
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  #67  
Old 03-02-2010, 09:16 PM
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Well, things are way off then. With the tube in I am getting 20mV on pin 3 and 7.4V on pin 2 . I am getting a couple of mV on the + side of the 10uF 25V cap.

oops
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  #68  
Old 03-02-2010, 09:35 PM
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I just checked continuity of the pins on the 6F6 tube. The only continuity I get is between 2 and 7. Nothing else. I don't know if that's good or bad.
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  #69  
Old 03-02-2010, 10:23 PM
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Quote:
Originally Posted by de.facto7 View Post
Well, things are way off then. With the tube in I am getting 20mV on pin 3 and 7.4V on pin 2 . I am getting a couple of mV on the + side of the 10uF 25V cap.

oops
Those are the filament pins on the 6F6 so that's OK. I hope you meant to say 10uF 400V cap not 25V. That's what the schematic specifies for C-14.
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  #70  
Old 03-03-2010, 12:25 AM
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There's a 10uF 25V at C-31 which was in a dry electro pack together with a 4uf 450V. I guess you meant one of the big caps on the top. On this model (A66) it was an 8uf 500V. I replaced that with a 10uF 500V electro. That voltage reads non existent.

You know, I'm going to take a step back and do some checking. The learning curve has been a big one in the last couple of days. I'm just wondering if I should make sure there aren't mistakes that I wouldn't have noticed last week that I would notice now. You never know.
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  #71  
Old 03-03-2010, 09:14 AM
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When you measured the voltage on C14 were you trying to measure it as AC or DC? The filament voltages and the voltages on the plates (pins 4 & 6) of the 5Z5 (5Y3) will all be AC. Everything else is DC.

I hope I don't sound condescending when I ask you questions like this because that is not my intention. I don't know what your experience is with working on electronics so that is why I am asking about how you are taking your measurements. I used to work in field service for my employer and did a lot of troubleshooting over the phone with people who did not know how to use a multimeter. I used to have to tell people to put the switch on their meter to the horseshoe for taking resistance measurements.
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  #72  
Old 03-03-2010, 12:41 PM
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Ha... yeah, It's OK. I have no problem being reminded about the most menial things. I have many time had the wrong meter setting just out of forgetfulness. My computer electronics is very good. My PCB work is fair. My radio and general electronics knowhow is well into the learning process but a long way to go. The old stuff is so different than anything I have had to troubleshoot. Just say what is direct and I can put it to use. No worry. It is actually appreciated.

Martin
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  #73  
Old 03-03-2010, 05:42 PM
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Quote:
Originally Posted by sean View Post
I used to work in field service for my employer and did a lot of troubleshooting over the phone with people who did not know how to use a multimeter. I used to have to tell people to put the switch on their meter to the horseshoe for taking resistance measurements.
Reminds me of my days working in internet tech support telling people to click their mouse twice really really fast on the big blue E. LOL btw, I like your avitar - brings back memories!
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  #74  
Old 03-03-2010, 09:43 PM
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Well, in stating the obvious, something is killing your B+. I would next suggest that you disconnect everything from the rectifier socket that does not come from the transformer, power the radio up, and see what you have. If your voltage is back up, then you have issues further down the line. If your voltage is still flatlined, then there is something wrong with that 5y3, or the way you wired in the new socket. Whatever it is, we're getting to it.
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  #75  
Old 03-04-2010, 11:18 AM
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Hey, I'm back.

I clipped the only thing that is not transformer from the 5y3 socket and the 5y3 is removed. I did leave the ground on pin 1 though???? I have full power (370V AC) from pins 4 and 6 to chassis and 5.5V between pins 2 and 8. I'm guessing the reason the voltage went down from 7.9 to 5.5 is that I have the other tubes and the lights connected now. Last time none of them were in. There is 0V on 2 and 8 to chassis.

I have a confusion question... How do I check the polarity of the circuit where the 10uF 500V electro is? When I put the cap in, I was just following what I thought was the correct position based on the old cap. The old wiring was too discolored to make out. I don't want this thing exploding in my face when we do figure out what the power problem is with the 5y3.

Thanks!
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