I would like to have this one! Seller says it had an RCA service contract until 1978, and was working until the late 80's until arching began in the high-voltage section. It would be great if it was the flyback and not that damn picture tube. If the tube is good, it needs to go to an AK member! Also, it probably needs to be picked up! Wouldn't trust UPS on this one........ LOL

And here's the link, for those who hate searching...:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2198191921&category=3638

It's stunning, no doubt about it!!

-Kevin

Boy these sets sure are common now aren't they? ;) This one is a real beauty though. I wonder how high the auction will go. The economy seems to be depressed for stuff like this now and I've noticed a slump in vintage TV prices.

I can't believe I forgot to post the link...... See what happens when one is supposed to be working? I should have shoved ALL work aside. LOL :)

WOW! Depressed tv economy? $1,000 opening bid! I'm really interested in seeing what this baby goes for. Would be wise to go pick it up. Hate to see a shipper damage such a set. Is anybody close going to go see the set in person? Folks in my world wide car club go check out cars for each other all the time. I am not bidding just interested in what an expert has to say about the set. It is like like finding an unknown HEMI convertible.
1950's style convertible that is! I know car collector and a TV collector all wrapped in one person. Trouble is what will get space in the garage!!!!


polaraman

Originally posted by polaraman
WOW!... It is like like finding an unknown HEMI convertible.
1950's style convertible that is! I know car collector and a TV collector all wrapped in one person. Trouble is what will get space in the garage!!!!


polaraman

Yeah, one classic vintage car in the living room can displace a lot of vintage TV's to the garage! :D

I wonder if Pete Deskins, the foremost authority on ct-100's(ctc-2) rca roundies, knows about this one. If so, i'm sure he might be interested.

Otherwise, I hope one of us at AK gets it!( I can NOT afford to even THINK of bidding on it!)

( I checked Pete's site... He Knows!)

This doesn't look good though :(

Could you explain where you see the problem? Is it gas/air in the tube?

The problem is the barely visible, cloudy area just to the left of the silver portion of the lower gun. That is where the very silver tube getter should be.

The getter was a compound applied to the neck wall of a CRT (and most small tubes) to absorb the last molecules of gas in the tube when it was built.

The problem with 15GP22 tubes is that the front of the tube containing the phosphor screen and mask was attached to the bell portion of the tube with a sealant. Over time most of the tubes have developed a leak at that point which allows air in and eventually overwhelms the getter until it starts to go from silver to chalky to almost gone. Much like the white powder in small tubes that appears when it cracks or you drop it.

It is the quickest indicator of the condition of a tube without testing.

Dave A

Dave A,

Nice explanation about the getter! Actually in the photo it looks like there may be some getter left above the top gun in the photo. If there is some getter deposit left and it is still silver I'd guess the tube quite useable. Once run for a bit the occluded gas may be gettered into the phosphor and shadow mask by e-beam bombardment.

So the question is, what happens if you attempt to put filament voltage to a tube that's obviously open to air, and is there a way to bring it to vacuum again?

Tim,

Once the delicate emissive coating on a cathode has been exposed to air it gets contaminated and re-evacuating doesn't revive it. If you apply power to the filament of a tube with poor vacuum or gone to atmosphere it will just burn out

I alerted Pete about this CT-100. He has posted the
auction number. I also e-mailed the seller to try and obtain the serial #'s for Pete's site. I was curious about the picture tube condition. There seems to be some disagreement on that from the members. :dunno:

i also noticed the getter looked cloudy. why didnt he get an actual picture of the getter. looks suspicious to me. steve:dunno:

Here is a pretty good explanation of what happens inside a CRT to all of the elements as they age;

http://www.muter.com/English/01BMRRTECH.htm

Rob, I can't remember how manny getters they put in that tube. Perhaps as many as three. I don't have my 15GP22 near the office desk at the moment, so I will check tonight to see how many getters were actually flashed in the neck. I would think they would all degrade at the same rate.

Dave A

my 15g in my ct-100 has one that i can only see,i had the tube out over a year ago and looked carefully.could only find one!..:)..

opps..I lied.. there are three.. out of my out curiousity i took mine apart,mine works fine.. here are pics..

getters on my 15gp22

2nd

3rd getter on my 15GP22,right side,now i have to realign it..:)
silly me..
terry

If you look closely at the picture the top getter looks even cloudier than the one on the side.
I would bet $20 that tube is aired out.

Since we're showing off our guns :D here's my C-73599. That's the experimental type number progenitor to the 15GP22. Mine glowed pink in the neck around the gun when I fired up my '54 Westinghouse and when a HV vacuum leak tester is brought near the neck or sparked to the pins. I'd guess the vacuum has deteriorated to probably 50 microns Hg or maybe worse. That's the kind of vacuum you can pull with a single stage mechanical roughing pump.

ok here is a better pic of my tube just shot,without so much flash..
terry

Here is another photo of a 15" full 'o powder except it is another prototype.

The prototype above is the C73293C early metal shell 15" used in either the Model 3 or Model 4. I forget which. It used the 16" B&W metal shell with an added mask on the front which was welded on. The "Rose Bowl" was the Model 5. RCA apparently never could make this tube tight.

This tube has the phosphor screen supported by the bolts you see and they were eccentric mounts so the shadow mask behind it could be rotated to align with the phosphor screen.

I got this from a TV shop that called me saying they had a 15GP22 they thought I might want. I almost choked when I saw it.

Dave A

I guess I'll jump on the picture tube bandwagon. This is my Sylvania ST-1507 engineering sample CRT.
Chuck