The AM Forum

I found some 7 pin tube sockets in the pile. Two larger holes and five smaller holes, arranged just like a 1625 socket, but the holes are too far apart for a 1625 tube and too close together for an 813. Anybody know what fits in these sockets??

Thanks, Ron

Not sure what you have, but I am aware of two standard size 7-pin sockets smaller than the 813 socket.  The smaller size fits receiving tubes like the 6A7 and 6B7. The larger size fits the type 59 receiving tube, as well as the 802 and 837 transmitting tube.  I'm almost positive that the 1625 also uses the same larger size socket.  But if your socket is too large for a 1625, it must be for still another size 7-pin tube, larger than the 1625 but smaller than the 813, unless I am mistaken and the 1625 uses the same size socket as the 6A7, etc. receiving tubes but I don't think that is the case.

There are a lot more tube bases out there than I ever expected.

Here is a link to a bunch of them:

http://www.tubedata.info/bases.html

The 59 and 1625 both use what is termed a Medium 7 pin base.
The ones you have may be foreign?

Carl

Flat porcelain job?

Maybe the Septar, like on the 829B.

73DG

He said 2 big pins which leaves out the 829B family, 4D32, 4-65, 8877, etc.

Oh yeah, I forgot those only have one big pin, kinda like me ;)

73DG