GE M935AWL roundie part 5 - cataract post-op

[@joernone]

Your decades of experience told you there's no need to risk damaging that CRT neck, so removing the yoke and convergence coils was of course the wisest way to go.

[@allisonbarnhardt3647]

Looking good so far. You can get black RTV silicon at auto parts stores and my experience with the yokes and convergence assemblies on that vintage makes me say pull them since the plastic they use has become quite brittle over the years. I remember one I dealt with in the 1980's when I was in Collage being very miserable. Seeing you work on these reminds me of the RCA CTC-7 we used to play Atari 2600 games on. Make me regret pitching that set now.

[@oldradiotvsc9836]

Looking great! Excellent progress!

[@krz8888888]

Looks great, good job

[@garp32]

Looking good!

[@billharris6886]

Bob, nice work! Considering this was your first attempt, the complication, number of steps, and a CRT much larger than you are used to; GREAT JOB! I would highly recommend removing everything from the neck during the catarct removal process to reduce weight and improve ease of handling the CRT. Besides, even if all the adjustments remained untouched, you would still need to repeat the color setup. Also, all the stuff on the neck is 60 years old and delicate.

[@bandersentv]

Thanks. I do work with 21" rectangular CRTs all the time that are even heavier as they used thicker glass

[@bigaudioal]

Looks great, Bob! Nice job!

[@69Dartman]

I like your compromise. You listened to everyone's advice and thought it over and put your spin on it👍 it does look really nice physically and it looks good picture wise so I'd say it's a success. Once you get the guns all lined up it's going to look really nice.

[@johnchildress6717]

It does look very nice.Like new old stock.Hopefully a few examples of sets of this quality will be around to see.Another 50 yrs it will resemble Fred Flintstones car.

[@compu85]

On a 12" mono crt in an ADM3 terminal I used black double sided foam tape, no silicone. I don't have the computer part of the terminal working yet so not many hours on it yet, we'll see how well it does with keeping the dust out. Your repair came out great!

[@dbridger620]

Excellent work, Bob! As always, I'm looking forward to the next installment. Looking at the service literature for my Zenith 25LC20, I noticed they marketed sets that used the bonded 21FJ and a few more economical models that used the non-bonded 21FB with a shiny clear safety glass separated by a rubber gasket. I would think it would put to rest any possibility of the PVA adhesive adding a measure of implosion protection.

[@randomsteve4288]

Sorry to partially object here. I would strongly advise against leaving the deflection and convergence assy on the tube unless it is ABSOLUTELY stuck on. Like you pointed out; due to the way the yoke assy is attached it will probably shift from its position anyway and need readjustment. But the worest thing is that the yoke adds unnecessary weight. As you seen yourself, it is a struggle to flip the crt upside down into that trashcan without snapping the neck by hitting it on the brim of the can. Now imagine the yoke putting more weight on that neck, making that whole thing in your hand more prone to tipping down and smashing itself while you adjust your grip on that front. If you had someone help you flip that tube upside down, or someone slightly tip over the trashcan, so the whole ordeal becomes a more controlled effort, it may be an option to leave the yoke attached. But handling that chunk of a tube solo, there is too many severe cons in leaving the yoke assy on to even consider it.

[@mikefinn2101]

Bob many thanks update been waiting each installment very happy to see another great video just love this channel

[@tomj4506]

Some sets the CRT comes out as an assy with shields etc. Pull them whole & transfer parts over on the bench. Easier on back etc. LFOD !

[@peterbondmusic]

I just keep thinking of Shango, who can often be seen doing pretty risky things, yet he is always wearing protective gear when removing cataract from a colour roundie CRT...

[@rossthompson1635]

I agree - however confident and familiar you are, accidents happen. When the consequences are potentially life-changing, I think it is a mistake not to take precautions.

[@garystrait3289]

That does seem like a good idea for this cataract removal, since you're heating the CRT unevenly. Even if you heat the face of the CRT evenly, the cone is probably much cooler. Who knows what thermal stress that may be inducing.

[@chetpomeroy1399]

It is my understanding that later models also incorporated minerals/compounds into the protective glass that acted as a shield to protect viewers of the set from low levels of ionizing X-radiation.

[@garystrait3289]

After recently restoring a 1972 Heathkit color set that was plagued by out of spec carbon composition resistors, and recapping after the set had sat for years, I found all the purity and convergence adjustments were out of adjustment and needed to be redone, and that was without having removed anything from the neck (I replaced components on the convergence board too to get all the old out of spec stuff out once and for all before realigning, so I'd only have to do that once). You may not save yourself much work by trying to leave the yoke and convergence assemblies on the neck of the CRT, since you may want to, or need to readjust everything anyway after you get done replacing weak components. Plus, leaving everything on the neck of the CRT leaves less room for error in getting the CRT into and out of the trash bucket without whacking the neck, and either knocking things out of adjustment, or even necking the CRT. The plastic may be old and brittle, but I think it's probably better to remove and replace, rather than do the cataract surgery with everything still on the neck. But, if you want to try leaving all that on on the other set, you can give us your advice on which way is better. I'm guessing you may end up needing to realign things even if you leave all that stuff on. Next, time, do take measurements for where everything is positioned on the neck (how far forward from the CRT socket), especially the convergence assembly. There is a correct position for those parts to be lined up with respect to the gun assemblies inside the CRT. Convergence may not work as well if they're too far forward or back. You should do that for initial placement of the yoke too, but you'll be moving that for purity adjustment. Your purity actually looked not too far off when you powered the set back up, so it looks like you got it close already. And the CRT and convergence assemblies all need to be right side up, or the convergence adjustments won't work correctly.

[@bandersentv]

There is a band of tape around the neck and I have photos showing the relative position of the convergence coils so I do have some reference. Should be close to where it was originally.

[@notimetolooz9655]

Don't overlook the fact that since you removed and replaced the components around the neck that the centering and size may be off. The picture is looking good however!

[@FluffyTheGryphon]

Every old set I've worked on in my very short tenure in TV restoration has had a separate safety glass mounted in front of the tube. This leads to a lot of stuff getting in between the two layers... dust, bugs, cigarette grime, etc... So bonding the glass to the tube may have been done in some models as an attempt to mitigate that? I don't know.

[@bandersentv]

Evolution of CRT design. Separate glass was on the way out in the mid 60s. First bonded safety glass then came tension bands.

[@FluffyTheGryphon]

A bit of an odd question, have you had to rebuild any flyback transformers?

[@bandersentv]

Nope. Don't think I've even encountered a bad one. Mostly I work on 40s-50s B&W sets that have robust flybacks and I have spares if needed. Color sets are far more demanding and prone to failure.

[@leetucker9938]

round crt are weird , TV was never transmitted with round pictures was it ?

[@bandersentv]

Nope. Making a rectangular picture tube is difficult so they were round for a few decades.

[@leetucker9938]

@@bandersentv I can remember tv's from the 80's onward. B and W then colour. never watched a round one

[@AKATenn]

there aren't many, not sure there are any, game studios still around that were popular 20 years ago. there are game studios that have the same name and logo as those studios, but all the people and the culture that made them what they were have long since gone. it's sad to see, but I think people are starting to realize that the phrase "in name only" is a fact.

[@williamholtonjr.8577]

15:35 A GE showing a GE

[@johngalt7382]

My condolences to the sweep tube cha ching $$$. Is that a 6LQ6? ugh

[@bandersentv]

6JS6C

[@johngalt7382]

@@bandersentv Much easier, but still painful.