Hello, I have an RCA 6T71 with a weak, metal sided CRT. The weak CRT's number is 16GP4. Can I substitute an all glass, 16FP4 crt? Would I have to do much modification?

Here is the schematic for my 6T71

http://www.antiqueradios.com/gallery/v/ ... ewsIndex=1

Not that I know what I'm talking about, here are the problems.
The original fits into the front mask, with clips to hold front in. One of thos clips also is the second anode connection.
The glass tube has a larger, thicker bulb. It will be difficult to fit it in the mask.A new second anode wire with the correct plug can be made. That isn't the problem...
Also, it may have a deeper bell than the 16GP4. That would be another problem.
I saw this tube, and, believe me, if I had any hope to use it, I'd be running to purchase the other.
Perhaps a set that uses that tube will come up. It might be a goood buy for you for that purpose, but, in an RCA, I doubt it.
Good luck. Personally, I think another good 16G will eventually show up.
I was lucky. I have an RCA with a cabinet that is in dubious condition. It had an original RCA tube in it. I thought it was dead. My low grade re built tube in my Admiral started failing with use. I tested RCA tube, and, it checked good. I put it in the Admral, and, it shows a nice picture.
Usually, original RCA tubes have gone to air for me... I feel lucky.
I think you will eventually find a tube for it...
Bill Cahill

Actually, it fits right in no problem. The TC-168 I picked up a while ago had one of those glass tubes in it, though if I recall correctly the glass tube was shorter so there were yoke mods involved. No biggie, it's easy to move.



The 16" metal tubes are scarce, and when you find them they are usually near death- low or no emission. I say use the glass one, mod the set to accommodate it. At least then you can use the set, while waiting for the correct metal one to show up.

Why screw around, when you can buy a new one:

http://www.ebay.com/itm/Vintage-NOS-Sil ... 460297ab85

I bought one of those Silver-Glo tubes for my RA-113 a few months ago and I'm happy with the purchase. The seller was very pleasant to deal with and they shipped instantly. You can read a bit about it at the end of this article:

http://antiqueradio.org/DuMontRA-113Television.htm

The price seemed fair to me, especially given that the last US picture tube rebuilder has closed up shop.

These are rebuilt tubes, by the way. Not a negative, I just mention it in case someone wonders why they never heard of the Silver Glo tube manufacturing company.

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

oops! There's one for a bit cheaper than the one I found on ebay. Good eye. I guess I kinda skimmed over that listing that you gave because the CRT in the picture was rectangular. I'll remember that seller though.

I can't wait until the early television museum starts rebuilding picture tubes.

I can help you with a crt. I have many good used ones.

Do you have good used 16GP4s?