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#31
05-21-2023, 09:37 PM
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I GOT IT!!!
http://suzaku.live-evil.org/0521232104.jpg UGLY cataract.. RCA style! http://suzaku.live-evil.org/0521231638a.jpg neat speakers! http://suzaku.live-evil.org/0521231638b.jpg Houston we have a T933 chassis http://suzaku.live-evil.org/0521232104a.jpg wired up for test, got no emissions at first, WAKE UP!! http://suzaku.live-evil.org/0521232106a.jpg 20 MIN later. http://suzaku.live-evil.org/0521232107b.jpg found this this thing on the bottom of the cabinet, where did THAT come from  http://suzaku.live-evil.org/0521232108.jpg Who stole the tuner cover!?!?! more later!
__________________
=^-^= 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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#32
05-21-2023, 11:52 PM
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I recently restored a Magnavox T931, which is very similar to the T933. I think the T933 added horizontal centering circuitry and maybe horizontal size controls. Instead of using DC restoration via a diode clamper, Magnavox used partial DC coupling of the DC bias from the video detector. This makes the brightness less consistent than what you get with a diode clamper DC restoration design, but it is better than nothing.
The TV’s focus coil is a bit weird too. It can be locked into position, and unlocking it is sometimes a challenge. I wish they just kept it a normal screw type adjustment slug transformer. I am curious to see the state of your T933’s flyback. If at any point you give up on that TV, I am interested in buying spare parts for my Magnavox. I need a replacement “clover” style dynamic convergence assembly, as mine is cracked due to over tightening. So I’d be interested in buying parts from you. Last edited by LukeSimon; 05-22-2023 at 12:23 AM.
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#33
05-22-2023, 10:17 AM
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Just placed a order for a bunch of electrolytic capacitors for the set, as I'm sure they are no good as always.
The flyback transformer looks clean, shockingly clean, TOO CLEAN almost, it has had an easy life, or has been replaced, never seen one this nice before. http://suzaku.live-evil.org/0522230602a.jpg This is obviously a custom cabinet, because one dumb thing about it, there is no room to get to and open the side cover on the HV box w/o swinging the chassis out for room. Another thing that was noticed was, all the screen controls were turned all the way up almost, this does not match with the rather decent emissions that were shown with the CRT tester, meaning some fault with the chassis to be worked out, likely a weak selenium boost rectifier like I had in the Hoffman Colorcaster, or some other fault in the CRT circuitry.
__________________
=^-^= 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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#34
05-22-2023, 08:24 PM
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My T931 had screen cranked even though CRT emissions was good. It turned out that the horizontal blanker tube V19 (6GH8A) was tired, and when that tube gets tired the DC bias of the picture tube G1 anodes becomes very low. So you should try swapping that blanker tube for one that is know to be good.
In fact, the only low emissions tubes in my T931 were the three 6GH8A tubes. Chroma demod didn’t work until I replaced the 6GH8A that was used for the chroma oscillator. The T933 chassis is almost identical, so consider swapping those 3 6GH8A tubes out for NOS. All of the electrolytics were still within spec too, except the two on the convergence control board. My T931’s flyback looks great too. I think it is due to the fact that the horizontal efficiency coil was tuned for absolute minimum horizontal output tube cathode current. Tuning that coil doesn’t just decrease wear of the HOT, since the HOT is in series with the flyback transformer, that coil’s tuning decreases the wear and tear of the flyback transformer. Last edited by LukeSimon; 05-22-2023 at 08:32 PM.
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#35
05-22-2023, 09:57 PM
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http://suzaku.live-evil.org/0522231939.jpg
Very very dirty chassis, and smells of smoke, (tobacco) http://suzaku.live-evil.org/0522232147.jpg much better! not gonna even try to power it up till the weekend, it will have plenty of time to dry.
__________________
=^-^= 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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#37
05-23-2023, 05:40 AM
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Quote:
__________________
=^-^= 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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#38
05-23-2023, 06:05 AM
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http://suzaku.live-evil.org/0523230557.jpg
you can see it in this bad coil from a BW set, it's sealed with some sort of enamel material.
__________________
=^-^= 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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#39
05-23-2023, 07:57 AM
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I did my t933 some years ago. I also had the blanker tube make the picture tube look bad. Over the years of owning it the degauss themister/varistor failed, the high meg resistors in the vertical failed and one of the convergence coils on the clover opened up. Mine has all original power supply electrolytics and the original flyback. I adjust the HOT current whenever I replace the output tube. I use it an hour once a week.
They can make a good picture!
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#40
05-23-2023, 08:18 AM
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The blanker tubes went every few yrs. It may be why the G-2's are high.
TNR shield often missing or hanging loose in Magys. Tuners were constantly dirty & messy techs just tossed them. Maggy even tried tuner pads, no joy. Dont remember who built them but they were in other sets & didnt have problems. Go figure Part you found looks like its part of a coil form with the slug. Look on the CONV panel. 73 Zeno  LFOD !
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#41
05-23-2023, 08:26 AM
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Quote:
 one must have been broken and replaced in the past, no telling HOW LONG that piece has been in there!
__________________
=^-^= 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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#42
05-23-2023, 06:59 PM
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DAMN! there is NO ROOM to reach under the chassis to change out C1, it's just too tight under there.
__________________
=^-^= 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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#43
05-23-2023, 08:34 PM
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Quote:
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#44
05-23-2023, 08:47 PM
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Quote:
__________________
=^-^= 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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#45
05-23-2023, 10:04 PM
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https://www.youtube.com/watch?v=QFl25sRnB0E
many weak tubes most are still the original. gonna have to check all the resistors as well but FIRST video
__________________
=^-^= 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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