#1
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Admiral 19A1, no vertical sweep (video attached)
Well, here I am rolling along on BigAudioAl's Admiral. Complete recap, etc. Here's where I'm at. Thoughts?
http://www.youtube.com/watch?v=5qgng...ature=youtu.be
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#2
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Have you either tested the vertical output and oscillator tubes or substituted them with "known good" tubes. Sometimes the substitution method is the best; that way there is no question about the electronic integrity of the vacuum tube.
There are so many possibilities that I guess people will hit on with this common symptom of no vertical sweep. I think that the next most important question to ask you would be: Was there vertical sweep before the "recap?" You could have a bad vertical output transformer, a potentiometer or a bad yoke. There are resistors across the yoke windings that can bad or have cold solder joints. I'll stop there so some others can maybe elaborate. I hope this helps.
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"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free" |
#3
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I didn't plug it in before the recap. The caps looked horrible, and I didn't trust them....I knew from experience that there was no way I was gonna get anything on screen unless I replaced those 6 kV deflection caps, anyway.
The only thing in the entire set that looks like a real abortion is the horizontal sweep transformer. New leads soldered on inside, and a wrapping of black tape on the outside. I'll assume that it's working though, since it has horizontal sweep. I'll try tube substitution next. I just thought that it was really odd that I'm getting what sounds like horizontal sync bleeding into the audio.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#4
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The high megohm resistors near the vertical size control are reasonable suspects... I have seen the 10 meg ones *really* increase in value and kill the vertical, but the others are also suspect. Might want to ohm check the vert osc xfmr as well. Good Luck!
jr |
#5
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Sounds like you are good for now in the horizontal realm with the exception of that audio/horizontal noise that you describe. That description of new leads being soldered on and "a wrapping of black tape" around the flyback transformer sounds scary and may be the heart of that noise you are hearing.
However, nothing in the horizontal circuitry is going to bring back the vertical sweep. Try the tube swap first, then work from there. Good luck.
__________________
"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free" |
Audiokarma |
#6
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I don't see a yoke, flyback transformer, or vertical output transformer on my schematic for an Admiral 19A1... It is a 7" electrostatic set.
jr |
#7
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Someone mentioned to me that you can't use disc caps for the 6 kV vertical deflection, but they'll work fine for horizontal. Seems to me that I remember using disc caps for a VT71 I did years ago.
I'll hop on it tomorrow again and check those resistors. Thanks for the advice
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"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#8
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Quote:
jr |
#9
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I don't know about the tv, but after yer video there was this GIRLFRIEND ZOMBIE ATTACK video I just had to see, and then I forgot about your tv a little more....
http://www.youtube.com/watch?v=PIVtr5kYvmU Give it a try, you'll forget about that tv......
__________________
Yes you can call me "Squirrel boy" |
#10
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What TV were we talking about that was awesome.... seriously though I had the same exact set check the linea te controls on the back. they usually need a really good cleaning in my case it was simply burnt open I replaced it and the tv went back to normal. as for the black tape on the transformer be extremely careful I mean extremely careful the winding on that transformer use wire that is about the size of a human hair. my Transformer failed shortly after the set begin to make a quiet squealing sound I managed to solder the broken wire but when I moved it by accident it broke way back by the core my set is now DOA until I can find another transformer.
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RCA VICTOR and its dealers bring you...... |
Audiokarma |
#11
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And believe it or not that could also be a tuner issue
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RCA VICTOR and its dealers bring you...... |
#12
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First question is on capacitor C2B, the 50 uF section of the big white or tan filter cap under the bottom. I need to know where this goes, along with a couple pictures of the wiring at the end of said red wire.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#13
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Greetings from FixitLand!
No one's said this yet, surprisingly, so -- PLEASE turn the brightness DOWN on that set while it's showing only a bright horizontal line, lest you burn that line permanently into the phosphor! Good luck on the fix, -- J. E. Knox "The Victor Freak" |
#14
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That is turned down. I played with the shutter settings on the camera.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#15
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As to the vertical circuit: once you get it working at all, I have a suggestion
for it that resulted in "oohs" at the picture it made on my lowly Pilot TV-37, which has the same circuit idea. My change was to replace the capacitors feeding the vertical deflection plates with much much higher value 6kV ceramic ones. Actually my set could use 3 kV ones but yours need the 6kV ones. I would suggest 0.05 uF but 0.03 would work. Parallel cheaper ones if necessary. Its still not terribly expensive. What this does is increase the time constant of the circuit so that there is no "exponential droop" during the 1/60 sec. scan time. Then remove the odd 20 meg resistor between the vertical oscillator plate and the second vertical output plate. The waveforms on the plates of the two output tubes will then be much more linear than the very odd ones shown on Rider's ( and which were similar to those on my Pilot before the mod.) And due to the much larger capacitors they will be essentially identical on the picture tube deflection plates. |
Audiokarma |
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