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#1
02-12-2012, 12:43 PM
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Rca t-120
guy gave me a few sets, this one was the best of the bunch. Has a good 12LP4 that had most the dag falling off. I picked up some slip plate brand spray paint, that worked great. It looks completely un touched. I started with a full recap of the tubular caps. EVERY one of them was bad, no big surprise as they were all papers and bumble bee, and black beauties. EVERY can cap section was shorted, so they got restuffed as well, had 3 on the top and 1 on the bottom, bunch of electros. I check a few of the resistors esp the ones that were on term strips shared by the tube caps getting replaced. I can't decide if I want try my 5" test crt or bother with reinstalling the 12LP4. prob go with the test crt just to see how it works.
oh will go thru all the tubes for shorts 1st I tested the sweep tubes, mostly 6sn7's and the HOT all tested fine. I just dont want a shorted tube ruining a resistor somewhere. 
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#2
02-12-2012, 06:54 PM
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got it. At first the horz was way off, would lock on 3 images. It ended up just needing the horz transformer bottom slug needing to be adj A LOT which surprised me. I checked the sync sep pulse with a freq couner and it looked good (15750 or there abouts) but the drive signal to the HOT was 125750. I adj the bottom slug to note which direction would speed up the osc, several turns out did the trick so now it has a rock solid sync.
The voltage divider resistor then shorted out to the frame, I was able to stick a piece of cardboard in there to temp stop that, and the 850 section opened up as well (same section where the short was) so I will have to order up some power resistors to complete it. will need to figure out a neat method for insalling them, I like to keep all the parts in the same location (like stuffing can caps) but the power resistor will be a challenge.
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#3
02-12-2012, 07:45 PM
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Could you simply solder the new resistor across the old terminals? Maybe make sure the old stays open by cutting the element a little.
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#4
02-12-2012, 11:20 PM
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it seems to be shorting to the chassis, hard to tell. There were two unused points on a term strip nearby, I did the open section there the 215v to 135v 850ohm. I Made up a 850 from 4 5w sand resistors i had on hand. a 300+350+100+100 in series. I work out to about 3watts 3.5 watts 1 watt and 1 watt. No wonder that resistor is out back its nearly 9 watts total (and the spec says a 7 watt). There are still two more a 650 and 650 they seem ok for now but I will fix that next time I go to the surplus store. I pretty much used up my supply of sand resistors. I do like the 5 watt jobs in series, maybe a 300+350 for the 650's.
Its working great now, I have posted some pics over at ARF.
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#5
02-13-2012, 01:48 PM
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Quote:
Thanks, Rick
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#7
02-13-2012, 03:20 PM
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Grainger part #1WVK7. (I have it memorized now... Hmm, it could be a good password for a Web site.)
__________________
Chris Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
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#8
02-13-2012, 08:08 PM
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Hey we need the photos to be loaded on VK so those of us who are not on AK can see them thanks,,,
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#9
02-13-2012, 09:55 PM
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dinked around some with it, added a cap and resistor in series with the CRT cathode and brightness control, this pretty much eliminated all the retrace lines that were a problem in low contrast scenes.
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Linear Mode
