CRT Motherload!
 

Got an E-Mail from a local collector who had noticed I needed a 3KP4 for a Pilot, well he thought he had one, (or maybe) three, turned out he had four so he sold me three, along with two 7JP4's, one 8BP4, two 10BP4's and a NOS 5AZP4, which is an Aluminized version of the 5TP4 projection tube.

All of them are good as promised, the two 10BP4's test like new and one of them is the A version with the tinted faceplate, the 3KP4's are bright and sharp as are the 7 & 8 inch electrostatics.

He didn't give them away but I consider the deal to be outstanding for what I got!

I have three Pilots and now they can all be restored to working, I also have many other sets that were in need of good CRTS that I can now fix.

Congrats! Not every day that even a quarter of that happens.

Do you mean a 10BP4A, or a 10AP4? I have a set that needs a 10AP4.

Wow! I think most of us would love to stumble on something like that. A 3KP4 is one of the few things on my want list (so rare that I don't even bother mentioning it).

The 10BP4A.

10AP4 is Pre-War?

10BP4 = Clear Face
10BP4-A = Gray Face
10BP4-C = Clear Face, aluminized
10BP4-D = Gray Face, aluminized

All four will interchange.

I've no information on the "B".

The C and D were special order for use in very bright area use.

James.

Wow! I'll wager you have the only surviving 8BP4 without a brown center!

This tube was the ion burn king!

I tried to find a replacement for mine in about 1958 and although they were still listed in the catalog, neither the regional dealer, nor the home office had one or could get one.

I know that some people have done it, but you better check on the 5TP4 directly interchanging with the 5AZP4.

The "Z" needs a higher anode voltage and more shielding. I think the curve of face plate is slightly different.

James

10AP4 is a prewar Philco tube. No set that used it was ever made in production quantity so the chance of that tube randomly turning up from a repairman's surplus
is close to nil.