1966? Zenith Color Tube TV

[Yamamaya42]

SuperZed21? :O



I think I found u on u-tube! :P

[Yamamaya42]

A few things about your YT video.

The appearance of the horizontal output tube, you can't judge a tube's life based on the appearance of the flashed getter spot alone, it can often be very misleading.
https://tubesound.com/brown-or-black...not-mean-used/

The tube in the shielded area in front of the HV box, the spec often is that they can be mounted in any position, and often are :p They tend to radiate outward in a circular pattern from the bottom, so an open top is minimal x-ray risk.

Broken CRT cap / socket guide, this is very VERY common with these type tubes, and the bane of their existence, I need 2 myself, if someone could find a way to make them, they could make a good deal of $$$ :O

But the most disturbing thing was the broken convergence coil, with the wire jus hanging out like that, the plastic on it just deteriorated? O_o

[Lain94]

Originally Posted by Yamamaya42

SuperZed21? :O



I think I found u on u-tube! :P

Ahhh you found me! XD

[Lain94]

Originally Posted by Yamamaya42

A few things about your YT video.

The appearance of the horizontal output tube, you can't judge a tube's life based on the appearance of the flashed getter spot alone, it can often be very misleading.
https://tubesound.com/brown-or-black...not-mean-used/

The tube in the shielded area in front of the HV box, the spec often is that they can be mounted in any position, and often are :p They tend to radiate outward in a circular pattern from the bottom, so an open top is minimal x-ray risk.

Broken CRT cap / socket guide, this is very VERY common with these type tubes, and the bane of their existence, I need 2 myself, if someone could find a way to make them, they could make a good deal of $$$ :O

But the most disturbing thing was the broken convergence coil, with the wire jus hanging out like that, the plastic on it just deteriorated? O_o

Interesting I was never sure about how the x-rays would radiate directionally as I do not know all that much about x-rays other than wanting to avoid them.

I was wondering about the CRT socket guide breaking as being a common issue. I am not sure if it just degraded from age or if someone was being too rough with it a long time ago.

Oh yeah that was one of the most annoying things about this tv, at first it appeared to be only one of the convergence inductors was in need of replacement as it was dangling like an unspooled ball of yarn and dangling. The plastic literally was so brittle that just barely touching it made chips fall off...later when taking the panel off a second convergence inductor spool also had its plastic brake. Luckily I have since managed to get them replaced and had a ton of confusion about how to install them direction wise as it was unclear. What is even more strange though is other plastic parts in the tv seems perfectly fine and sturdy as if brand new. I am suspecting the ones exposed more to the sun were the ones degrading. Maybe some of them had a different type of plastic?

[Electronic M]

Originally Posted by Lain94

Interesting I was never sure about how the x-rays would radiate directionally as I do not know all that much about x-rays other than wanting to avoid them.

I was wondering about the CRT socket guide breaking as being a common issue. I am not sure if it just degraded from age or if someone was being too rough with it a long time ago.

Oh yeah that was one of the most annoying things about this tv, at first it appeared to be only one of the convergence inductors was in need of replacement as it was dangling like an unspooled ball of yarn and dangling. The plastic literally was so brittle that just barely touching it made chips fall off...later when taking the panel off a second convergence inductor spool also had its plastic brake. Luckily I have since managed to get them replaced and had a ton of confusion about how to install them direction wise as it was unclear. What is even more strange though is other plastic parts in the tv seems perfectly fine and sturdy as if brand new. I am suspecting the ones exposed more to the sun were the ones degrading. Maybe some of them had a different type of plastic?

The pin locators on rectangular color tubes were common failures the heat tends to degrade the plastic. It's especially bad on Japanese sets, but on domestic sets it tends to happen more on high hour tubes.
Whenever I encounter a dead CRT with a good plastic socket guide I tend to save the guide.

[old_coot88]

The hor. 'efficiency' coil usually goes 'Slinky' before those convergence coils do. It may have already done so and been replaced. In any case, you gotta verify that it's intact and that the form shows no sign of crystalizing. It's finely tuned for a resonant dip of the H output cathode current. If the coil loses resonance, the K current skyrockets, risking red plating the tube.

[julianburke]

I am guessing year of manufacture is 1966. Chassis number is either 25MC35 or 25MC36. All tubes are there. Last date of power up unknown. Appears to have never been recapped. I saw some of those annoying and unreliable wax paper caps in there and can already say i am not bothering to power this thing on until i replace the wax papers and do a thorough examination of this thing when I have the time.

This model was for the 1968 season. When I was in high school I worked for MusicLand here in Knoxville and we had these on the show stand. I liked the "power channel changer" button. Could have come out in the fall of 1967 but certainly NOT 1966 as the roundies were still around.

[Yamamaya42]

Originally Posted by julianburke

I am guessing year of manufacture is 1966. Chassis number is either 25MC35 or 25MC36. All tubes are there. Last date of power up unknown. Appears to have never been recapped. I saw some of those annoying and unreliable wax paper caps in there and can already say i am not bothering to power this thing on until i replace the wax papers and do a thorough examination of this thing when I have the time.

This model was for the 1968 season. When I was in high school I worked for MusicLand here in Knoxville and we had these on the show stand. I liked the "power channel changer" button. Could have come out in the fall of 1967 but certainly NOT 1966 as the roundies were still around.

Well, by definition, roundies will always be a round!
Could not resist myself!

[Electronic M]

Originally Posted by julianburke

I am guessing year of manufacture is 1966. Chassis number is either 25MC35 or 25MC36. All tubes are there. Last date of power up unknown. Appears to have never been recapped. I saw some of those annoying and unreliable wax paper caps in there and can already say i am not bothering to power this thing on until i replace the wax papers and do a thorough examination of this thing when I have the time.

This model was for the 1968 season. When I was in high school I worked for MusicLand here in Knoxville and we had these on the show stand. I liked the "power channel changer" button. Could have come out in the fall of 1967 but certainly NOT 1966 as the roundies were still around.

MC chassis were 1965 unless there's a Z at the end of the chassis number. NC is 1966, XC is 67, YC is 68, ZC is 69 and they circled back to A for the 1970 model year. If there's a Z at the end of the chassis number that indicates a chassis that got carried over into a second year of production.

In 1965 Zenith rolled out their first rectangular color, but they made and sold roundys that year and at least the next 2 years. The roundy chassis they made the next 2 years was the 24NC31. I own a 24NC31Z set that was a 1967 carryover of the 1966 24NC31. Zenith actually made some production changes on the NC31Z (comparing it to a previous year NC31 parts chassis I have) the most notable being switching to the bell fuses later Zenith's used.