RCA CT-100 on ebay

[reeferman]

Pete,
I may want to take my bet back. The installation instructions note "that the matched kinescope is is shipped in a separate carton but as a part of the same receiver". The carton shipped in the bottom part of the receiver contained the yoke, purity coil, and kinescope mounting components. Since the chassis first had to be removed to mount the 15GP22 and associated components, I can see the chassis being delivered, out of the cabinet, for two possible reasons: the technician can give the chassis a "once over" before installing it, and it would lighter on the guy's back. Looking at the tag, the person who filled it out seemed to be very deliberate in their handwriting, so I'm sure if there had been a repair date, it would have been included.

Phil

BTW, at the shops where I worked, we ALWAYS replaced all the screws.

[Pete Deksnis]

Originally Posted by ctc17

Say it doesn't sell, do I want to pull the crt and apply vacseal right away?

I don't know if anyone says for certain that it is fully effective. The successful RACS 15GP22 rebuild now on display at ETF was sealed with frit material, not vacseal. However, if/when you decide to remove the CRT, realize that just this year it was learned that the HV flange is extremely susceptible to edge damage; the flange can be the point of a leak. John Yurkon, Bob Galanter, and John Folsom did the work. Take care not to bang the flange edge into something.

Pete

[Pete Deksnis]

Originally Posted by reeferman

BTW, at the shops where I worked, we ALWAYS replaced all the screws.

Phil,
And always one or two tubes minumum!?...

Pete

[John Folsom]

Opinions vary regarding Vacseal, whether or not after application it would stop or prevent a leak. However, there is no downside to applying it, other than the risk of damage handling the 15GP22.

Once Bob Galanter and I get our helium leak detector up and working we will be able to apply some science to the art of leak detection and repair.

[reeferman]

Pete:

Phil

[WA3WLJ]

Vac u Seal works for systems that are about to be put under a vacuum AFTER YOU APPLY IT !!!!!

Since the tube is fine ; adding it now will only stop future leaks, which you don't obviously have after 56 years ! We ONLY use it at NASA when we assemble parts, then put them under a vacuum during leak testing to suck the glue into the leaking joint. Since it's not leaking adding it now,( and if your lucky finding the spot where it might leak in the future) is a waste of time.

[Steve D.]

Quote from Pete Deksnis post #28: "the photos seem to show all four scuff-pads are in place under the four knobs in the pencil box. I have a pristine CT-100 that has the pads, and that set is the only one that I have personally seen with the pads."

Pete: My CT-100 serial # B8002407, Cabinet-lid-panel # 917 has the 4 original maroon colored discs (scuff pads) under the front control knobs. I bought my set many years ago from a retired RCA Service Co. executive. It is rare when these pads survive. Interesting that ebay CT-100 and its owner/collector is about 30 minutes down the freeway from me. Who knew?

-Steve D.

[Phil Nelson]

Originally Posted by Steve D.

maroon colored discs (scuff pads)

What are these made of?

Phil Nelson

[jr_tech]

Originally Posted by Phil Nelson

What are these made of?
Phil Nelson

Mine are stiff dark-gray/black fiber about 0.020" thick 1.195" diameter with a 0.290" hole in the center. they are tinted dark brown to match the knob on one side.
jr

[kx250rider]

Originally Posted by jr_tech

Mine are stiff dark-gray/black fiber about 0.020" thick 1.195" diameter with a 0.290" hole in the center. they are tinted dark brown to match the knob on one side.
jr

I think they're phenolic. I have a few of them, as they came on a lot of RCAs from the early 50s through the late 50s; not just the CT-100. If you dig deep enough in any box of knobs, you'll find those. They filter to the bottom along with orphan knob springs, and moth-eaten felt washers.

Charles

[jr_tech]

Originally Posted by kx250rider

I think they're phenolic. I have a few of them, as they came on a lot of RCAs from the early 50s through the late 50s; not just the CT-100. If you dig deep enough in any box of knobs, you'll find those. They filter to the bottom along with orphan knob springs, and moth-eaten felt washers.

Charles

Yes! that is the word I was looking for.

"Phenolic sheet is a hard, dense material made by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin."

jr

[Steve D.]

Jr and Charles' discription of the scuff pads is right on. I couldn't think of the word phenolic either in my post. In better light the discs are not maroon as I stated but a dark mahogany brown with a shiney coating on the front and flat black on the back.

-Steve D.

[Username1]

On this Vacseal stuff, does it dry hard? I can imagine if it does not remain soft and squishey on a surface that does not now have a leak, then if one develops it will not be "sucked" into the leak and seal it. Kinda like the self sealing tires, the stuff inside is always sticky. I wonder is a good chemical clean of the area, and application of a silicone glue or something that remains rubbery is not the best to apply to a surface that may or may not leak at a known spot......

[Phil Nelson]

I felt the Vacseal on one of my tubes about a month after sealing. It had cured beyond the "almost tacky" stage, but it didn't feel as hard as, say, cured varnish. This was casual feeling with a fingertip, not scientific inspection, and there's no way to know what's going on under the surface, of course.

I've been told that these leaks, when they happen, are at the microscopic level. If you apply something like glue, my question would be whether it's truly impermeable in the first place. A rubber balloon seems impermeable when you blow it up, but it eventually deflates because gas passes through the material.

We're all just guessing until John & Bob can apply some science to the question. I put Vacseal on my tubes on the theory that it probably won't hurt and it just might help. They don't leak now, but they had gotten through the previous 50+ years without leaking, so the fact that they haven't leaked yet tells us nothing. Vacseal is expensive stuff, but cheap compared to the cost of a good 15GP22.

Phil Nelson

[jr_tech]

I may be off base here, but I believe that the very tiny leaks that we are trying to stop on CRTs are much too small for a liquid like vacseal to be "sucked into". I look at it as a dense low-vapor pressure coating that essentially provides a second containment wall, in case the first fails. I have painted it around CRT neck pins, base pins and tip seals as a preventive measure. I have no statistically significant proof that it did any good, but in those small quantities, it is pretty cheap per application.
jr