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#16
09-20-2020, 11:16 AM
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Definitely needs a lot of work...
https://imgur.com/FYKd8kn Screens at max for this, brightness ctl has almost no effect, NO color, just causes green hue on screen. ( huge feeling of déjà vu here  )many dirty pots, most tubes original. screen should be much brighter given what my CRT tester showed me. Set is most likely full of leaky caps.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために 
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#17
09-20-2020, 05:45 PM
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The only thing that I wonder now is, what kind of cataract am I dealing with here, someone said that the CRT was a RCA type, but CRT so far has no markings or labels on it, so I'm not sure who made it.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 09-20-2020 at 08:43 PM.
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#18
09-20-2020, 07:40 PM
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Quote:
Zenith types cataracts (also found in other brands like Sylvania) develop a gummy green halo. RCA and Zenith evenly split about %85 of the TV market in the 50s-70's so people tend to name the 2 cataract types after the 2 brands each is most often found in. The gummy ones can be cut with guitar string (my favorite method). All will be affected by heat (which can be dangerous) and some Will come off with water.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#19
09-20-2020, 09:22 PM
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Quote:
as mentioned, it should be much brighter given how it tested on my tester, it almost but not quite as good testing as the one in my 16xl and it is VERY bright with bias at lowest setting and screens hardly turned up, so SOMETHING is not right here... strangely this set has no CRT bias setting, and another odd thing I have seen that when shut off, there is a bright flash of raster seen on the screen as it powers down, IE screen is dark when on, shut off it gets brighter for a second as just as the sweep collapses, telling me there is most likely a bunch of electronic stuff to fix. I wonder if I should try soaking this cataract, or would that even work on it? but first things first, ( Hana Yori Dango ) , i need to finish the SC tv before I really start this one! 
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#20
09-20-2020, 10:49 PM
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This is just pure speculation at this point, as I have only had the set on for about 30 min to evaluate it, and not even pulled the chassis yet.
I have no idea why they chose not to put the CRT bias in like RCA does. https://i.imgur.com/6XruNV1.jpg it's hard wired to the lowest setting via the 47k resistor R170, that is the area that in RCA sets that the bias switch is, that has dif resistors to change the bias, if R170 has gone up in value, it would no doubt cause a dim screen even with a good CRT. once I start working on this, I will most likely replace that with a 50K 2 watt Pot, that will give me a way to adjust CRT bias on this thing.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#21
09-21-2020, 11:08 AM
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What is the normal range of bias voltage? I would be cautious about using a pot if the voltage is high. Parts in this area might have to withstand momentary CRT arcs too.
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#22
09-21-2020, 11:41 AM
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Well, I can just go ahead a stick the proper switch in there and resistors to go with it, there IS a place for it in this chassis, it was just not put in, also gonna have to find a new CRT socket that is NOT overpriced. :/
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#23
09-21-2020, 07:10 PM
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looking a bit better!
https://imgur.com/eCBI6Us color works! I tacked a 75k ohm resistor across the 47k one to bring the bias up a bit, tha made things a bit brighter, for now. I most likely wont have to resort to this after I go over things and replace out of tol caps and resistors.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#25
09-24-2020, 10:46 PM
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OK, What I think I'm gonna do with this CRT is, get a cheap kiddie pool, stick it in my shed, fill it with water, and a bit of ethylene glycol , take the CRT, remove the tape covering the sealed area, perhaps pick away some of the bad cataract with a spudger tool around the edge, and let it sit... and sit.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#26
09-28-2020, 10:17 PM
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chassis removed...
it is a lot lighter than the CTC-16 is https://i.imgur.com/efQcOV0.jpg https://i.imgur.com/63XTKUJ.jpg https://i.imgur.com/CdsulOR.jpg ummm, that USED to be a thermistor...  but i doubt it's the reason alone for the diim screen,
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 10-01-2020 at 06:14 PM.
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#27
09-28-2020, 11:02 PM
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The 2 main filter caps in the voltage doubler already seems dodgy , should be 2x 160 uf but they check 1 at 182uf and the other at 194uf,, seems unbalanced to me.
160uf is hard to get, gonna get a fresh pair of 180 uf.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#28
09-28-2020, 11:44 PM
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These values are within 20% of nominal and should be just fine in that regard.
If they are the originals, the main thing to worry about is leakage/failure, but those capacitance measurements look OK.
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#29
09-29-2020, 10:32 AM
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Unfortunately, I have no real way to test the electrolytic capacitors for leakage.
 I do have testers, a cheapy Mega328 LCR-T4 Transistor Tester, 2 DVMs that test caps, and a more pricey LCR meter, and all tell me generally the same thing within 3%-5% of each other when I test caps with them. The Mega328 is the only one that shows any kind of leakage reading at all, but being powered from a 9v battery I don't put much faith in it for a accurate leak test for 200v+ caps. And granted, when I DID power up and run this set, it was on for over 40 min, and all the electrolytic capacitors cans were still cool to the touch, so I guess that is a good sign that the are OK, not leaky. And unlike my CTC-16XL, which had all the resistors replaced on the chroma/luminance PCB everything in this one is all original, so I got to check it all.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#30
09-29-2020, 08:47 PM
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https://imgur.com/RiRALCS
OK  Lets see how long this takes! It is literally floating in the bathtub. It SAYS GE on the tube but it still looks a lot like a RCA tube. but unlike with my CTC-16XL, I had to remove the bracket around it cause it in the way if the safety glass.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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