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#16
11-14-2009, 08:24 PM
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thanks for the offer but need a 4 wire. I will try moyer monday to see, I am just looking around to see if I can find a sub part number. Its a pretty darn big autoformer. this is the second one in a month that had a bad vert, 1st the RCA CTC 16 and now this little maggie.
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#17
11-14-2009, 08:28 PM
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I may end up attempting a fix, maybe get lucky on the break (its not shorted the last leg is open, would be nice if its on the outside and not the inside. there is no evidence of trama to it, but something is up, the two defection windings had be cut and reconnected, poorly I might add, I don't think it is orginal to the chassis.
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#18
11-14-2009, 08:35 PM
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one more option I am thinking about is gutting a ratty magnavox color set for its CRT and chassis and makng this a color set, I dont really care that it is not original (not exactly a colletor item, at least not now) but I would love to have a color set in this neat little console, esp with the tube amp for sound.
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#22
11-16-2009, 02:49 PM
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No joy on the vert out from moyer, No joy on the other lead I got from ARF, so now I will contemplate pulling the tranny and seeing if I can find the continuity break. If I am lucky the break is early in the winding starting from the outside (its on the end, just which in the inner or outer) sorta like those disney chipmonks, the one that got canned it the tomato canning plant. He was in the very last can opened by his buddy, when he got out he just said " I was in the very 1st can you just started from the wrong end".
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#23
11-16-2009, 06:16 PM
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hmmm since its not shorted, and the only problem is the blanking leg, perhaps I can work around that and get the blanking off the yoke windings. I have seen a couple schematics like that, looks like some kind of voltage divider used to tap the yoke windings. 1st though is I have to see if the vert osc is working, and if not why. I am assuming the blanking being open would not stop the osc, but maybe I just cant see it if its getting blanked out I do get some vert on the raster, but most of the CRT is blacked out, just a smudge of raster about 1/3 high and about 1/2 wide. I don't know enough about the blanking signal to know if this could be caused by the open leg.
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#24
11-29-2009, 04:43 PM
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ok got full raster now, just re stuffed all the can caps. I have not tried feeding it a signal yet, I know I need the horz sync diodes replaced (one is open) and there is no blanking pulse (vert output tranny on the way).
I think I am going to try open up the existing tranny and see if the blanking circuit wire is just broken right at the output. I just was happy to see the full raster. Need to clean up the shop now that it is working. Since I am new to TV it should be interesting to see how the pic looks with no blanking signal at all, so will replace the horz afc diodes and feed it. This will be a good learning exp as I will see what it looks like when it is bad (so I can diagnose problems like this in the future a little bit better).
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#26
11-29-2009, 06:32 PM
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dug out a couple strong IF tubes getting a pretty decent pic now, still want to replace those horz AFC diodes (even though it seems locked in ok). The blanking is completely disconnected.
the horz osc seems odd, it was fine then I heard it slow down, lost HV and parts started getting hot. I quickly adj the horz pot and the HV popped back on. It has a new horz osc tube. Guess I need to check the voltage drop across the HOT cathode resistor and see where my current is. Its like I cant adjust the fine tuneing enough to get a real clean pic. I don't know if that is the lack of blanking or not. Will only be able to tell when I replace that vert out tranny.
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#27
11-29-2009, 09:13 PM
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well some more fiddling and I get a good clean pic now. If I turn down the contrast I get horz white lines. I assume these are retrace lines due to the disconnected blanking wire from the vert autoformer.
I had to add a 1 meg 10 meg resistor over the 2.2 meg resistor in the vert osc height control to get the vert big enough.
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#28
11-30-2009, 09:08 AM
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just for grins I put in a couple shot 6bq5s (did not want to put in good ones since I have not recapped the amp), got some sound out of it then hum set in and the rec tube started to red plate. So at least the audio detector is working, but I will need to work on that amp before trying again.
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#29
11-30-2009, 05:44 PM
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Quote:
__________________
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#30
11-30-2009, 06:39 PM
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looking better all the time, replaced the horz afc diodes, had to re adjust the horz osc coil, checked the HOT cathode current right on the money (124 ma). I will be adding a cathode fuse later and maybe a B+ fuse as well. pic has a bit of a lnterlace problem, but seems to be settling down. You can work it out pretty well with very careful adj of the vert hold but it is just a little to critical. It seems to be getting better as the tv is used. I dont know what circuit in the set conrols vertical interlace sync phase inverter perhaps?
I will check that tube its a 6gh8 by subing with a working one. other tubes include the sync sep /video output tube a 6eb8. and of course I can check the various resistor in and around those same tubes. If someone can explain how the interlace is controled pls jump in.
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