View Full Version : Will this be a leaky one?


old_tv_nut
03-25-2016, 07:55 PM
1953 press photo of welder joining a color CRT faceplate to the bell.

colorfixer
03-26-2016, 05:27 AM
Timeframe would make this the C series engineering tubes used in the Model 5?

Steve D.
03-26-2016, 02:14 PM
RCA welder taking a break........

-Steve D.

Electronic M
03-26-2016, 03:26 PM
RCA welder taking a break........

-Steve D.

:lmao:

reeferman
03-27-2016, 12:41 AM
Already has.
Is that a doctored photo?
There seems to be a lot of shadows where they shouldn't be.

6GH8cowboy
03-27-2016, 08:40 AM
Looks as if the socket was removed from the crt. This on never made it to a home.

dtvmcdonald
03-27-2016, 08:50 AM
The picture looks absolutely ordinary: one main, one fill, and perhaps a bit
of ambient light.

The socket can't be put on until its evacuated. The wires do look
a bit uhhhhh non-pristine.

jr_tech
03-27-2016, 01:07 PM
Looks to me that indeed the tube had been pumped, sealed off (the copper evacuation tube is crimped off) and wired to the base cap (solder blobs are visible at the ends of the wires). Perhaps this is a test reject that was un-based for this photo? Another remote possibility could be that this was a re-work loop where the weld of a gassy tube was touched up and the tube would then be re-gunned and re-processed. :scratch2:

jr

Eric H
03-27-2016, 01:07 PM
A couple odd things, the evacuation nipple appears to already be pinched off, also it looks like it has Getter spots and that they are already white.
It also seems to have some base cap adhesive residue around the edge?

Possibly a bad tube being used for a publicity photo?

Eric H
03-27-2016, 01:12 PM
I see Jr and I had the same thought at the same time.

If this is the case then these tubes were leaking before the first set left the factory.

Phil Nelson
03-27-2016, 01:59 PM
Possibly a bad tube being used for a publicity photo?From my experience in the magazine business, magazine covers and publicity photos are always staged, sometimes with ridiculous (from a technical standpoint) results. They are created by art directors, not engineers.

The artful lighting in this one suggests they did not just walk up to an active production station with a camera. More likely, they pulled a junk tube out a bin and staged the whole scene with dramatic lighting to maximize the visual impact. For all we know, the guy in the welder's hood is a janitor or assistant layout artist, whose time was less valuable than an engineer's.

Great photo, in any case. That's a 15GP22 tube, right?

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Tom9589
03-27-2016, 03:14 PM
Phil,

Look at the clothing in the picture. It's a woman in the picture, not a guy. She was probably the person who actually welded the tube.

andy
03-27-2016, 04:55 PM
It looks like the welding arc was added after the picture was taken. I doubt you could take a picture of a weld in progress without serious exposure problems.

wa2ise
03-27-2016, 05:26 PM
They may have been given a tube that went to air, as it would be safer for non-techies to handle. No implosions if they fumble it...

Steve D.
03-27-2016, 06:08 PM
From my experience in the magazine business, magazine covers and publicity photos are always staged, sometimes with ridiculous (from a technical standpoint) results. They are created by art directors, not engineers.

The artful lighting in this one suggests they did not just walk up to an active production station with a camera. More likely, they pulled a junk tube out a bin and staged the whole scene with dramatic lighting to maximize the visual impact. For all we know, the guy in the welder's hood is a janitor or assistant layout artist, whose time was less valuable than an engineer's.

Great photo, in any case. That's a 15GP22 tube, right?

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Phil,

The date on the publicity notice is Nov. 1953. This tube may have been an early 15GP22 or more likely an RCA developmental C-73599 tri-color tube.

-Steve D.

Steve D.
03-27-2016, 06:15 PM
Photo from the RCA 1952 annual report shows yet another welder at work on a 16" RCA developmental tri-color tube. Photo courtesy ETF site.

-Steve D.

ohohyodafarted
03-28-2016, 12:51 AM
Thanks for posting this Wayne! Where did you find it. This is the best quality example of this photo I have ever seen and it answers some questions I have had about the welding process.

The tube is obviously a dud that was used for photographic purposes. The lead wires and gun were not in the tube at the welding stage in production. Guns are installed after the tube is welded.

With the good resolution in this photo, it can be seen how the rotary welding table operated. Just the very edge of the metal ultor rings are exposed for welding. The rotary welding jig has an upper and a lower pressure ring that conceals most of the ultor rings. I always imagined that there was some sort of heat sink protection, and I would imagine the upper and lower pressure rings are probably machined from copper. You can see the rollers on the clamping levers that are used to apply pressure to squeeze the the two halves of the ultor rings together during the welding process.

This is an outstanding photo Wayne! Where did you discover this and are there any more in this series of photos about the 15G?

Thanks,
Bob

old_tv_nut
03-28-2016, 01:10 AM
I got this from Historic Images:

http://www.historicimages.com/

EDIT: they also sell on ebay.

As their web site explains, they are involved in digitizing newspaper photo archives, which they then sell piecemeal on their site.

There are other similar outfits that I search from time to time, some of which are multiple sites owned by one organization.

Examples:
MMGarchives.com
NewspaperPhotographs.com
JP-TheMint.com

If you get on the email lists, you will find for some of them that they send you links to new sites that they name similarly, but which have content from different times or sources, or may offer images in different price ranges.

I did not see any other photos in this series, but I suggest going to these sites and any others you find and trying more search terms, because you never know what terms the person who wrote the listing will use - it can depend on any terms that happen to appear on the back of the photo as well as the listing writer's thoughts.

old_tv_nut
03-28-2016, 01:15 AM
Looking at the photo again, I wonder if they gave the welder a warning about casually flipping the welding mask down and accidentally hitting the tube.

DavGoodlin
03-28-2016, 02:59 PM
Look at those electron gun wires at all directions:scratch2:

While it was national news, that image could have been from the photo archives of The Lancaster Intelligencer Journal or New Era evening paper.

That building still stands today at 1000 New Holland Avenue, with a variety of tenants.

kvflyer
03-28-2016, 03:06 PM
Looks to me to be a "TIG" welder. Did they have that technology in 1953?

jr_tech
03-28-2016, 04:29 PM
It appears so:

"Russell Meredith of Northrop Aircraft perfected the process in 1941. Meredith named the process Heliarc because it used a tungsten electrode arc and helium as a shielding gas, but it is often referred to as tungsten inert gas welding (TIG). The American Welding Society's official term is gas tungsten arc welding (GTAW). Linde Air Products developed a wide range of air-cooled and water-cooled torches, gas lenses to improve shielding, and other accessories that increased the use of the process. Initially, the electrode overheated quickly and, despite tungsten's high melting temperature, particles of tungsten were transferred to the weld. To address this problem, the polarity of the electrode was changed from positive to negative, but the change made it unsuitable for welding many non-ferrous materials. Finally, the development of alternating current units made it possible to stabilize the arc and produce high quality aluminum and magnesium welds."

from:
https://en.m.wikipedia.org/wiki/Gas_tungsten_arc_welding

jr