Curious which vacuum tubes are considered the rarest in Old Tube Radios what years were they made, the type and for what brand and model radios? Bill...Maine

Sonora brand RA-1's and RE-1's come to mind for me,I've only seen 1 RA-1,no RE-1's.
Phil

These are tubes for domestic, household service.

FWIR: It is the WR-21, Gridleak has been searching for this...

It was used for one or two model years of Westinghouse radios. There was a similar ballast tube that was used during that era too. Again FWIR 1921-22.

WE peanut tube, the Meyers tube, Sodion tube again, very rare as the radios that used them did not get wide distribution...

Chas

There was a tiny 6-1/2" square by 10" high cathedral radio sold by Hahne's Department Store, Newark, N.J. in 1932. It featured four special made miniature AC triodes (all the same) and mercury vapor rectifier which were manufactured by the Radio Products Company specifically for that set. The triodes were electrically similar to a type 27 and have a scaled down 5-pin base that is 50% the size of a type 27 base. They are tubular shaped and the one in my collection has no markings. Since it and others seem to have no markings, it has been dubbed "M-27". Apparently replacement tubes were only available at Hahne's. Availability of the tube must have been short lived for the Radio Products Company was out of business by 1934. I have never seen any data reference to this tube in any tube manual nor have I ever seen a tube tester with a socket capable of testing this tube. A picture of the tube and cathedral radio can be seen in the OTB 23-2. The radio set is condidered to be rare.

The 6D5 wasnt very common, seem to be mostly in a few Canadian sets, released as an octal 45 and didnt go over well.

Carl

Wow Alan, The radio pictures are fantastic!! Looks like the variable "condenser" was the biggest component of the radio and sure dwarfs the tubes. That was quite a radio for that period. Thanks for sharing the pictures. It is nice to have the additional history on the M-27

The 50 was used in a few RCA and Sparton sets, as well as some early theatre and PA amplifiers. It's not "rare", but you'll pay quite a bit for one if you need it, and even more if it's the 250 S-bulb version.

Then there is the WD-11, used in the early RCA Radiolas; also on the pricey side, if you can find one.

Thanks for all the knowledge and history lesson on vacuum tubes very interesting! Bill

I have been told that the PENDD61 tube in my British Philco 444 was manufactured specifically for that model.

http://antiqueradio.org/Philco444.htm

I don't know if that makes the tube rare, but at least it's unusual in my book.

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

Now I know why I didn't get any responses to my want ad a few weeks ago......

Well the VF14 tube used in Neumann Microphones comes to mind.