When did you first observe CRT cataracts and Green halo?

[Zenith26kc20]

CTC 11 RCA. Terrible and that was around 1967 when I saw it.
The little RCA color hybrids had em bad too!

[Carmine]

There is a picture of me taken around '75-'76 in front of my grandparent's 1968 Zenith and you can see the green halo.

[holmesuser01]

My uncle had one of the last all-tube rectangular screen Zenith color sets, and we noticed the halo effect happening around 1978. The set had a hard life running an average of 17 hours a day. He replaced it after replacing the flyback 3 times in 3 years.

[AUdubon5425]

Our CTC-40 did not develop cataracts in the 20+ years we had it. My CTC-68 had a severe case when I obtained it last year and I suspect that was why it was taken out of service around 2001.

Guess it was the "luck of the draw."

[freakaftr8]

I think they started using a different bonding material around the CTC-40 era. I have a CTC-40 with the original HiLite CRT and the bonding agent is perfect! Then I have a CTC-17 with a replacement colorama CRT from 1980 and it's perfect too, but then I have a Maggie from 68, and the CRT was replaced in 69, and, green halo. It's almost like somewhere between 1969 and 70 they used a different bonding agent. Correct me if im wrong of course.

[Findm-Keepm]

Factor in heat as a cause for debonding, and you'll see why solid state/modular set CRTs fare much better. I can't recall too many that had cataracts - most were older tube sets.

While in the Navy, I was once stationed where the battery "locker" (the lead acid and NiCad battery charge and servicing shop) had a small 12" black and white TV with a foggy, almost out of focus picture. My only guess was the battery acid fumes had managed to etch or otherwise mar the CRT face.

Cheers,

[radiotvnut]

Originally Posted by AUdubon5425

Our CTC-40 did not develop cataracts in the 20+ years we had it. My CTC-68 had a severe case when I obtained it last year and I suspect that was why it was taken out of service around 2001.

Guess it was the "luck of the draw."

And, that CTC68 was a '74, correct?

The only solid state sets that I remember seeing with the green halo were a late '60's Quasar WID console and two early '70's RCA XL100 consoles. I don't recall seeing, in person, a SS set with the moldy looking cataracts. Now, my RCA CTC25 combo has cataracts and according to a receipt I found in the cabinet, the CRT was changed in '78. I don't know what brand as the rats, roaches, or whatever ate the label off the CRT.

[wa2ise]

Originally Posted by andy

I first noticed it on a large 60's rectangular console in what must have been the early 90's. It had dots of fungus starting to show up around the edges.

My grandma had a portable 19 or so inch B&W TV set (long gone, and forgot what make and model) that had dark spots around the outer regions of the screen. This was back in 1980 or so, and it was a mid to late 60;s set.

[leadlike]

Findm's story about the etched tv screen reminded me of a lab I worked at. Back in the storage room, we had a couple of specialty cabinets, including the blast proof metal cabinet, and a wooden one with metal hinges where we stored corrosives (18M HCl and HF acid, for instance). Well, the crap in that cabinet was impossible to keep, it would dissolve the caps to the bottles they were kept in, badly etch nearby glass containers, and most dramatically, dissolve the hinges on the storage cabinet itself!

[bgadow]

I recently pulled the crt from a set I am getting rid of, a Halolite from the early 60s. It must have been among the first to use a bonded tube. One unique aspect is that the faceplate is larger than the front of the crt and has ears made onto the glass for holding the picture tube in place. Were the bonding to fail I don't see anything that would have prevented the tube from simply falling down on the chassis. The PVA on this one looks great, though. Appears to be the typical Sylvania type which turns greenish. The edges that are exposed to air are viewable only from the backside of the crt and they have just barely turned color. The faceplate actually wraps around the edges of the crt; pulling it off would be a bear, I think. The old tube is all but dead, but I will get some close up photos before I toss it.

[AUdubon5425]

Originally Posted by radiotvnut

And, that CTC68 was a '74, correct?

Yeah, '73 or '74 - can't remember and it's pretty inaccessible in the shed right now

[drh4683]

Thanks for all the replys. It seems that people then started first seeing it around 1975ish, but it became a common occurance around 1978 or so. Very interesting.

I've done some of my own experiments with the PVA material. I save a few peices of "good" PVA from cataract jobs I've done in the past just to see what happens over time being exposed to air. So far, I've only noticed that the clear PVA over time turns cloudy.

I have seen some RCA sets from the 60's for example have zero cataracts, while others from the same year are terrible.

I agree with charles though, you don't really see cataracts after about 1969 model sets.

Its interesting how this happens and I'd really like to find out why some sets experience the problem and others do not and what environmental factors contribute to this happening. Is it sunlight exposure, or air? Perhaps its the TV usage that contributed to the problem, such as heat (sunlight can also contribute to the heat factor). Not sure. I wonder if there was a study published on this that had some definite conclusions as to why.

[Charlie]

My grandmother had a large dual-speaker VHF-only Zenith roundie. The picture went out in 1975. My uncle who repaired TV's tried replacing a few tubes... still didn't work. He told her he would not fix the set because he thought it was too old. He was a firm believer in solid state. She just put another set on top of the Zenith. The set stayed there till she moved out of that house in 1983. It never developed the typical Zenith halo during those years. The house did not have A/C, and being on the Gulf Coast, it lived it's life (and death) in a warm humid climate.

Probably just needed a capacitor. What a waste.

[andy]

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[Eric H]

I remember seeing the greenish halo on some sets back in teh late 70's, seems like Magnavox and maybe Zenith.

At the time I think I thought it was some kind of feature, like a shaded windshield on a car.