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A fellow brought me a Philco 16 Code 126 and he said that the 80 rectifier was glowing red and there were holes burned into the plates of the tube and a hole was burned into the glass of the tube.
Does this indicate shorted filter caps?
Thank you.
Oscar
nv3g
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that would be a good place to look,also may want to check xfrm voltages with rectifier out of the radio,may have shorted windings.
phil
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philco phan Wrote:that would be a good place to look,also may want to check xfrm voltages with rectifier out of the radio,may have shorted windings.
phil
If it didn't before it may have now if the abuse has damaged the tube to that extent! There's numerous other things that could ultimately cause it but if it still has old filter caps they would be my first thing to replace.
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Generally, if the rectifier plates light up cherry red, there is a total, smack-bang short right off of the rectifier. Further, by the time that happens, the power transformer is on its way to oblivion. The transformers that Philco used are sturdier than most other companies used, so there could be a ray of hope. You might resort to prayer, also.
I have an RCA phono combination, where this same scenario took place. the tube was an 82, which is a mercury vapor rectifier. In that one, it also burned a hole in a plate, and sucked in a dimple in the tube glass. The power transformer had to be replaced, of course, and the windings were ashes.
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Hello Doug Houston
Wow that tube reall got hot to beable to suck the glass no wonder why the power trans was toast.
Sincerely Rich
P.S. are you sure someone was not trying to make early Microwave oven out of that thing if needed I can get you a high powertrans from a old 70s microwave
It will give a lot more current draw then that little Rca powertrans how about replacing that 82 with megatron tube to while your at it then you can cook at the sametime I think that will be that wave of thne future a radio thats cooks
Sincerely Rich
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Don't plug it in again until you have found the problem. The big pins are the filament and the cathode. Disconnect any wires to those pins that do not go to the transformer. There should be only one. Then with a voltmeter between either of these (large) pins and the chassis or B - if it is floating, measure the B+ vloltage as you slowly bring the set to life under a variac. Shut it down if any arcing or "red plates" occur, for this means the tube is bad. If you get this far, it is the electrolytics 90% of the time, and a bad coupling capacitor the other 10%. Well, that's how I would do it. But I summarily replace the filter and coupling capacitors before evern attemting to fire the thing up. That's my 2 cents worth. I'm sure there will be other opinions.
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Thank You for all your help and suggestions.
Replaced the three electrolytic capacitors. The radio play fine and fortunately the power transformer did NOT get wiped out by the excessive current. Still have to do a few more things to bring it up to normal operation. Cooked it for over an hour and the current held at 900 ma.
Thank,
Best Wishes
Oscar
nv3g
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While you have the chassis out, you should rebuild the Bakelite block capacitors. The procedure is not difficult, and a little work now will certainly prevent future problems; the originals are sure to be leaky.
Tim KA3JRT
Tim KA3JRT