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1967 Black and White Zenith tube tv chassis 13X16(Z)
I now have my first ever Zenith Black and white tube tv to add to my collection. I have already recapped it, checked CRT emissions, tested all tubes, and did cleaning along with deoxit. TV was having arcing issues in the HV cage and I later found out it was due to secondary the two wire winding on the flyback having a hole punched through it from the HV leaking out causing the high pitched buzzing noise. Recapping did not fix issue, tried cleaning and using corona dope but no luck still, and eventually replaced flyback with NOS one and am going to further look at the old flyback and keep it for refurbishing as I do with any of these old parts. Nothing gets thrown away due to the rarity of these. Arcing issue now gone. Emissions of CRT are great! TV now works but I notice a brightish white vertical line in the center of the screen. Unsure of what may be causing this issue.
Chassis number is 13X16Z Very simple to work on and much less complicated than the color tvs I have looked at in the past. https://imgur.com/a/kL1cx76 |
#2
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Hi to all,
Hi Lain94, Photos 1 & 2, Zenith B&W TV. Photo 1 is a good TV picture. Photo 2 shows the horizontal brightening. Seems to be linked to the white text displayed. AGC issue? what do the experts think? Does audio buzz when text is displayed? Photo 3, EHT & H Scan cage section. Red anode connector wire seems to have a cut or brittle plastic breakup. See zone highlighted by red circle. Best Regards jhalphen Paris/France |
#3
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In some pixs the HV cup looks quite messy & HV rect socket turning green.
The filament winding arc is common, replace with flexible 20 KV wire. I see two pix of white lines. One hoz & the other vert. The kind of problem that nobody wants, at least without a full suite of test eqt. & tube collection. Good little sets IIRC only built for a year or two. Zeno |
#4
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Quote:
I've replaced the 2 wire HV rect filament winding of the flyback and or the HV lead to the CRT on several sets. A good source is curb find 90s CRT sets. Whenever I see a curb BPC that's sat a few weeks (garbage men can't legally take them) without being rescued I steal the HV lead and a handful of other parts.
__________________
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 |
#5
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Audiokarma |
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#7
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I have no clue what the guage is (it only carries the rect filament current so it doesn't have to be particularly thick), but the insulation HAS TO BE rated at least 20KV (30KV is preferable) for monochrome and 30KV (40KV is preferable) for color. The reason the filament winding arcs to the frame but the doughnut rarely does is that the frame is grounded and the filament winding has the full 8-25KV of the set on it with only one piece of insulation separating it from ground. The center windings of the doughnut have the lowest voltage on them (sometimes their grounded, but often their 100-450V above ground) so if the higher voltage windings of the doughnut closer to the outside have insulation failure they're usually more likely to arc to the lower voltage windings... Eventually creating a carbon track which eventually shorts out the flyback and kills it.
__________________
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 |
#8
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Replaced old HV wire and anode those goes to CRT with new replacement. Sadly issues is still persisting. Straight white bright vertical line on crt that is mostly in the middle sometimes a bit slight to the left. A bit stumped on this one and annoyed after being so close to fully restoring. No other symptoms. Anyone have any idea what could be causing this?
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#9
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A blurry bright vertical line near the middle of the picture may be due to a horizontal drive issue. Does the set have an adjustable horizontal drive coil? How about a horizontal linearity coil?
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#10
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Sadly no, I looked all over the chassis and the set as a whole. Then I reviewed the sam's photofact for the tv and it appears to not have any horizontal drive or horizontal linearity controls. Why would a tv omit an important control like this? I am assuming to cut costs? lol
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Audiokarma |
#11
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old Zenith ad with a mayonnais jar full of parts. They were not needed for the TV to work under "normal" conditions. Thats why a Zenith 12" costed $30 to $40 12" GE. For your drive line look at the hoz osc & output tubes first. BTW old Zenith B&W's had a width sleeve a.k.a lin sleeve. its between the yoke & CRT neck. Pulling it back will widen the pix but is NOT your problem. Often its missing, a lazy tech would just throw it away for more width. 73 Zeno LFOD ! |
#12
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OOPS
I meant the GE was about $80 vs Zenith $120 for a 12" B&W. Zeno |
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