View Full Version : 21FKP22 Sylvania safety glass question


DavGoodlin
03-03-2017, 02:00 PM
After breaking the safety glass on an RCA 21FJP22 (65-39 date) doing my first REAL cataract removal, I needed to make a corneal transplant from a much more tired RCA FJ, which was fully delaminated and has since been installed in a set with external safety glass:D..

After doing so, I realized there was a half-inch abrasion near the center top of the intended transplant safety glass. I tried buffing it with the Dremel and polishing compound without much improvement. Luckily, I have a 21FKP22 donor but its not the same type glass RCA used. Apparently, Zenith and Sylvania used clear and non-tinted glass, which let more light through at the expense of more defined reflection from room lights, windows, etc.

Before I go any further to remove the glass from the OEM Sylvania tube, I want to see if there is any knowledge of this difference. I have only time and effort to lose because the 21FK is stone-dead.

The Sylvania is the same age as the RCA its transplanting onto, and the slight cataract hints at RCA-style PVA rather than the yellowing gel of most Sylvania and Zenith CRTs. Does this sound right?

miniman82
03-03-2017, 07:23 PM
You're only 150 miles from me, and I have a lens I don't need. If you can make here it's yours.

Electronic M
03-03-2017, 07:35 PM
Is there a way to position the scratch to hide it behind where the mask dips in at the top or bottom?...If so that would be what I'd do.

bgadow
03-07-2017, 10:06 PM
On that Zenith I got from you, I transplanted the lens that was on the OEM crt (it had the type that wasn't bonded) to another 21FBP22 and just taped it into place.

I have a couple NOS lenses, as memory serves they're the frosted type but I can't remember 100%. You'd have to wait for my next trip north, though!

DavGoodlin
03-08-2017, 04:12 PM
The scuff mark is pretty small now but its only 4 inches from the center, so no way to hide it. The scuff could show up as a screen bug but I haven't had the CRT lit up.

The chassis is a GE CB21, and Im about halfway through a recap. Once I can light it up and see if its visible, I may take you up on a spare glass. The only reason I considered the Sylvania is that its clear and free of scratches, etc.

DavGoodlin
03-08-2017, 04:16 PM
On that Zenith I got from you, I transplanted the lens that was on the OEM crt (it had the type that wasn't bonded) to another 21FBP22 and just taped it into place.

I have a couple NOS lenses, as memory serves they're the frosted type but I can't remember 100%. You'd have to wait for my next trip north, though!

Maybe if you have that set open, take some measurements from the 6BK4 regulator tube shield so Bob Anderson can replicate one for his "new" Zenith of the same chassis.