New CRT working!
 

I put the 20CP4 in the Wilcox-Gay set tonight, it had a 21" tube in it from 1977, it was the wrong tube and it didn't fit the mask right and the chassis wouldn't slide in enough to get the knobs on, also it was an Electrostatically focused tube where the 20CP4 is Electromagnetically focused, this fixed all those problems.

I was a little surprised that this Aluminized tube needed an Ion trap but it does, no biggie.

It looks great, all the labels are missing on the back so I don't know which adjustment is the focus, it needs touching up but looks pretty good for right out of the box!

Found the Focus control and adjusted it, nice sharp scan lines now.

I made a quickie video.

http://youtu.be/LxQiuY4FInw

Very sharp-Like new again!

Awesome! I'm surprised at how many aluminized CRTs use ion trap's too. Maybe the main intent was a brighter picture and they didn't quite trust the aluminum to prevent ion burn ?

It really looks great. Makes me want a NOS CRT to put in something.

Hey, is that one of the Silver Glo tubes? My 17BP4 just arrived today. I wasn't expecting it to be aluminized; what a pleasant surprise. Super bright with no ion trap -- so bright that I had to turn the brightness & contrast way down to get a photo where the screen wasn't all washed out.

Now I can really enjoy watching my RA-113. I was so eager to take a photo that I didn't even notice the vertical centering still needs adjustment.

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

P.S. Anybody in the market for a weak 17BP4? My old one was watchable with a brightener, just not as zippy as I wanted for this favorite set.

Phil, yes, it's one of the SG tubes, really nice, I think these are new, not rebuilt or just regunned.
This one took the B&K meter to about 98 out of 100 on the scale.
Mine had the warranty card in the box, dated Feb 21 1966, does yours have a date?
I would expect them to be similar.

Should we send in the warranty cards? :scratch2:
They'll wind up here at 437 S. Illinois St Indianapolis: http://g.co/maps/xyyxn Now a "Gentlemans Club"

Yes, mine tested very strong, indeed -- as high as I've seen anything read on my Sencore CR70. I'm no CRT expert, but it looks like a new tube to me, not rebuilt.

The warranty card on mine is dated September 20, 1965, serial no. 33038.

Phil Nelson

That's a great picture for having the room lights on. :yes:

Equally impressive is that at least 3 of these have been delivered now without any damage. I wish there was a 21AMP4B in that bunch.

http://videokarma.org/attachment.php...0&d=1325829181

Hoffman Silver Glo
 

Here's the third Silver Glo crt (23CP4) installed and running strong. Although mine is definitely a rebuilt tube, it's still a great rebuild job and looks terrific. I have a warranty card dated Sept. 1971. Now if I could only locate a cover plate for the tuning mechanism............................

http://i642.photobucket.com/albums/u...d/DSC_0016.jpg

"I'm ready for my close up Mr Demille"

Is that the set you picked up in apple valley a few months ago? Sounds like you saved it.

What's the telltale sign? Wavy girdle on the neck indicating a weld in the glass?

Phil Nelson

Yep, that's the one.

Yes..to me the telltale sign would be some pretty heavy duty ripples in the glass neck. I've seen some new tubes with mild rippling, but this tube looks like rough seas........Bob

The neck of my CRT looks smooth, but I happened to open the Silver Glo warranty card and read this:

Notice: All materials and parts used in the manufacture of this tube are new except for the envelope and coatings which prior to re-use were carefully inspected to meet our high quality standards.

Which means all of their tubes were rebuilds, presumably. It's all the same to me -- my tube looks great.

Phil Nelson