Is this too good to be true?

http://www.wmicronics.com/index.html

I see mine on the list.

They've been checked out before - looks to be bunk.

It was bunk in 2006. Now its moldy bunk.

http://www.wmicronics.com/rebuilttubes.htm

I don't know if its bunk, or not, but I have a couple 5BP4's. Yep, white phosphor. Always considered them scope tubes. Did they actually use these on early TVs ? I've heard that early ones used electrostatically deflected tubes. I didn't think they went as small as 5".

I used to work in a TV service shop in Chicago when I was a youth.

We frequently had b/w CRTs rebuilt. There were a few re-builders in Chicago in the late 60s. As I recall, we paid about $15 a tube and got 2-day turn-around. The re-builder busted the sealing tip, cut off the neck, put in a new gun structure and welded a new neck on to the tube, then pulled vacuum and re-sealed.

The phosphor wasn't always in the best shape after a re-build. I guess exposing it to air, even briefly, degraded the chemistry.

Rich

I believe it was how careful the air was let back into the tube which determines how good the phosphor coating is after the rebuild.

Often, if air is let in too quickly, it will blow the phosphor coating right off the face.

-Steve

These are just a few of the 5" sets offered for sale by several manufacturers in 1939. With the exception of Andrea's sets, all used the 5BP4.

Rich: The Early Television Museum had a 15GP22 rebuilt in France a couple years ago that literally had had the neck open to the elements for years. With the exception of a couple spotted-looking areas, the phosphor plate was none the worse for its exposure and the tube is still in use.

Western Micronics never gave any of the collectors who called a straight answer about rebuilds and would only say they'd get back to you after they got their gun shipment or somesuch BS. That was on the rare occasion when somebody actually answered the phone--when it wasn't disconnected.

I remember reading about a company called Hawk-Eye that rebuilt CRT's. I haven't looked into their services in a long time so I was surprised to read they closed up shop. I know this is probably old news to a lot of you:

http://www.tvtechnology.com/article/las ... ing/206279

Looks like there is a group that inherited the equipment but they are a long ways from getting an operation up and running:

http://www.earlytelevision.org/crt_project.html

- Geoff

Steve's right. With the exhaust tip clean off some CRT types will lose all of it's phosphor coating off the panel, rather than a nice round clearing a few inches in diameter in the centre which is quite common. Even when the air is let in initially, you have to be careful because the phosphor coating receives knicks as it is removed at a molecular level, as the air molecules collide with the phosphor. Evidenced by shining a light in there and you'll see little tiny specks of light on the other side, with most of the specks in the middle. Quite often "violent" air-in's pull in glass chunks and other debris and if it is a color tube, this debris impacts the shadow mask and then it's junk. That's what I'm afraid is going to be wrong with mine, once I cut the gun off and peek inside I'm not going to be surprised to find any damage to the shadow mask as evidence of the kinds of debris that I'll find in there later. I can hear something shifting along the inside of the shadow mask frame when I have the tube on it's side and turn it.

Getting back on topic, if these people don't rebuild tubes, what on Earth is keeping the page up?

Some web hosting is quite cheap. Maybe they prepaid for 10-years, and went belly-up in the mean time. There was a guy that has my same last name, and owned the .com address. He died 5 years ago, and only now the name is becoming available. The vultures are contacting me hoping I want it bad enough to pay big money for it. I already own the .org . They can stuff it up their excretory orifice.

The web site was last updated in 2006.

With domains able to be purchased for 10 years and this website was designed by a company tat went out o f business in 2007 I suspect the site is just a remnant

The web is full of them.

This domain was purchased in 2004 and expires in 2013.

Thank's for that info, btw.

Maybe I should dig up an appropriate schematic, and try to replicate one of those TVs.

I visited a picture tube rebuilder somewhere in the Chicago area when I was a teenager. The firm helped to sustain itself with a contract with O'Hare Airport to rebuild the many 27" B&W CRTs that were used there for flight information displays. When a tube was rebuilt, it was completely cleaned out; phosphors, internal 2nd anode conductive trail and external conductive coating. The P4 phosphor was water borne in a slurry and poured into the envelope to a depth of about one inch. Then, after a long delay, the phosphor would settle onto the inside of the envelope's faceplate.
After the phosphor had settled to the faceplate, the water was very slowly poured out. I remember if this wasn't done properly the phosphor screen would be imperfect and what was called a "watermark" would spoil the resulting screen.
The aluminized internal coating was flashed electronically onto the inside of the envelope. It seems to me that the inside of the phosphor screen was spray coated with something that was later heat baked to ash, a process that also removed the aluminized flash from the backside of the phosphor screen.
The neck and gun assembly were welded onto the envelope, a vacuum and oven process was followed by sealing and the installation of the base and appropriate labels.
This was about 50 years ago, so some details have been made sketchy by the passage of time and a fondness for beer.

There was a rebuilder in the Montreal Area, which, I believe was called "Bill Still Electronics".
This was in the 50's. I do remember grumbling about longevity though.

Also old TV techs would buy indicator chassis from surplus shops that housed a 5BP4.
They got it powered up and then used alligator clip leads from the deflection plates
to the yoke socket, with the yoke plugged in, when the chassis was pulled w/o kinescope.
This and Z gave them a raster of sorts.

This was before those little test crts were available.

I suppose Video Display Corp. in White Mills, PA is no longer rebuilding CRTs?

That was where most of the CRTs came from while working at both TV shops.
Can't say how many A68ACT00X tubes I replaced in Zeniths.

-Steve

Loosely on topic...

If I am thinking right Hawkeye was in Des Moines Iowa and I beleive they shut the doors a year or 2 ago.


Todd

Last I heard Video Display was still running but they are only rebuilding certain late model crts, nothing vintage. I think they are kept running by various industrial and military equipment that can't be readily converted to flatscreen. They are becoming famous for listing picture tubes as being in stock on their website but actually being sold out. It would seem like they could make a tidy profit doing some vintage work given they are now the only game in town.

I hope the museum can get the equipment in place and up and running. Otherwise I feel we're back to sending duds to the landfill again.