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  #16  
Old 04-05-2012, 10:13 PM
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holmesuser01 holmesuser01 is offline
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The D01 was my favorite Sylvania chassis. The guys in the TV shop kept telling me how junky they were, but it seemed to me that the only real problems they had (that I can recall) was the issue with the bad resistors in the Y circuitry. The set would produce a good B/W picture, but the color picture would be allover the place, and would never get decent fleshtones. I saw a D01 a year or so ago, and it still has all of its oem tubes, and has been repaired once... an on/off switch... installed in the set back!
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  #17  
Old 04-06-2012, 07:39 AM
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DavGoodlin DavGoodlin is offline
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Thanks for a great thread!
I missed out on those good old Sylvanias. My Aunt had a D14 (1971 19" hybrid color) and the only thing I remember doing in the 16+ years it lasted for her was to clean the tuner every year so the Philly channels would come in (75 miles away) for March Madness and Baseball Seasons.

Worked for a Sylvania dealer in '81 while in tech school. I only saw the sets that were 3-7 years old, so I did lots of vertical transistors, triplers, etc. I did not like what NAP did to them in later years.

Great job!
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  #18  
Old 04-06-2012, 08:42 PM
DaveWM DaveWM is offline
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thanks DavG

I unplugged the tuner (nice) and cleaned it up, the UHF was stuck, just needed some solvent on the old grease, all good now. The VHF was stiff, turned out to be a tight fit of the plastic channel indicator drum on the brass shaft. I cleaned up, polished up the brass, used some very fine sandpaper to clean up the plastic, got it to a no slop but free to turn fit. Much better now. while I had it out I cleaned up the contacts and lubed the bearing spots.

Before I call it done I am going to go back and double check the HOT and shunt current. The Fly runs hot, but seems to be working fine and the last check of the cathode current was right at 200ma I can get it lower if I reduce the line voltage.

I will also check on some of the other parts that effect the HV regulation. I noticed that a bright scene will result in object being too dark, where as if the lighting is not high in contrast everything is fine. The CRT is weak, perhaps that is the problem, but I still plan the check the two other circuits that effect HV. The 1st is the feedback from the blanker tube, the neg bias at the grid is fed back to the grid of the HOT. This is a design to prevent too high a voltage IF the shunt tube fails. I can see a problem there if for some reason the blanker tube was gassey or for any other reason did not generate the correct neg bias. Next is the shunt tube bias that comes from the video amp. I understand this is to aid in adj HV when there are extended bright scenes. Its a fed from the cathode of the CRT back to the shunt tube thru a 12meg resistor.

I just want to sure that both of these systems are working as designed.
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  #19  
Old 04-07-2012, 01:45 PM
DaveWM DaveWM is offline
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check the few parts I mentioned, all looked good. did a recheck of the cathode current on the HOT and shunt, at 24kv I get 185ma and about 1.5ma with the screen blacked out, with normal video the shunt is around .8-1ma so all looks good. this is all with the line set to 117vac, the pic starts to dim if I get much below that (again a weak CRT). I could prob buck it down to 110vac and use a booster on the CRT, but that is getting a bit much. At the 185ma the fly just gets warm to the touch, so I need to make sure It does not see more than that. I have been toying with the idea of installing an adapter socket with the SCREEN of the HOT cut so I can adding resistance there to tailor the HOT current and not have to worry so much about the line voltage and its impact on the FLY. On some of my zenith rectangle sets I know they have a screen tap that lets you select the B+ when using different HOT's.

there also is something not right with the focus, I am at the extreme end of the adjustment (max voltage) for focus, if I go ever 23kv it will be out of range (its just barely there, I cant go beyond even at 22kv). So I really need to check the focus stick (I hate those) and maybe the 66meg.

oh the other thing that was odd was the eff coil did not seem to dip, it would just be lower if you moved the slug to either extreme (to the point it was coming out of the the coil form) so I will go back in and check the two caps that form the tank circuit (a .068 and .082 in series together, P across the eff coil).

Last edited by DaveWM; 04-07-2012 at 01:50 PM.
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