Hi,
I have been digging through my forgotten tubes. Testing everything I find. Weeding out the good from bad. I found a couple i would like to know better! I have this small ST type 8 prong RCA 2051. Also, a early type brass based 3 prong small global with TB1. Looks like it was sand blasted into the glass with a stencil. Will anyone please educate me on these tubes? Can I test the 2051 on my PACO T-60 tester?


Thanks, Andy

The 2051 is a gas thyratron and the TB-1 us a diode tube dating from 1918. First used by the Air Service division of the Army.
Curt

Hi Curt,
The TB1 would make a good display. This has no marking on the base. In excellent condition! The 2051 might be good? Wish I could test it. Anybody still use it today?



Thanks, Andy

I might be able to use the TB-1. I would have to check.

I have an ESCO wing generator (less prop) and a spare clutch sitting in my shed. I have kind of ignored it since I (thought) the nameplate said 8 volts. I guess it was for two VT-1's in series...

Should drag it out and and see if it is useful for rig filament lighting.

Love the whir of machinery. Have a great Century motor to spin it with too.

I surmise the TB-1 gets plugged into the rear somewhere. I haven't looked that thing in over 30 years.

Chas

Hi Chas,
I hhas no idea if the TB1 is good? It is in excellent physical condition. I see you are in Mass. I am in Brimfield,Ma. Let me know. We will work something out.



Andy

Andy, do you have an ohm-meter near you? You should have continuity between two of the three prongs of the TB-1.

Wasn't the TB 1 used in a wind generator WWI era.

I have a few NIB ones...

Hi Tubenutt,
I sure do! I will try it. Its really something how all this evolved from Edison's light bulb! The discovery of the "Edison Effect"!




Andy

Now, yer gonna make me dig my copy of Gerry Tyne's Saga of the Vacuum Tube out!

EDIT: The TB-1 was called a Kenotron, used as said, in wind generators in aircraft, so was EXCEPTIONALLY RUGGED, Tyne says. So that's why the darn thing STILL had a good filament! There were only about 4500 of them made! If yours has a Shaw base, it is of the early (pun intended) variety.

Ok,
The TB-1 is a Kenotron and used as a regulator in a wind driven generator. If you have Gerald Tyne's "SAGA" book, its covered on pg 147.

Yes, the TB-1 was used as a regulator tube for wind driven generator sets that were installed on aircraft. I believe it mainly worked as a shunt regulator, but I would have to dig out some old books to make sure.

But when the war ended, the Army Air Service, they found themselves vastly overstocked with these tubes and they were released as surplus.

They are actually a General Electric development and were called Kenotrons. They were advertized in QST Magazine for must of the 1920's and especially around the 1921 to 1924 time frame.

Since high voltage rectifier tubes had not been released yet, they were a way for a ham to obtain DC for his transmitter plate supply and a lot of hams did use them. I personally knew two hams from that time frame who are now silent keys, but they told me that the Kenotrons were very popular in the early CW days and that is what they used for plate power to their UV202 tubes.

I have never seen a socket for them, however. That would be very difficult to locate in my opinion. Give me a couple of days and I will see if I can find any of my early 1920's QST Magazines and let you know what the ratings on them were.
Curt

I doubled with the last two posters!
Curt

sure did! lol

Curt, Probably could re-index the slot in a metal shell UV socket.

If only 4500 of them were made, then the Army must not have used very many of them. Like I said, they were very popular with hams back then. But again, what was the number of hams in 1923-1924? Most hams back then were lucky to own a tube, and that usually wound up in their receiver while their transmitter was a spark rig that was rapidly being phased out.
Curt

I agree with Curt, there were SWEEPING changes going on in the field of communication right after WWI. I would love to see the pinout of that tube! And aren't we glad that they didn't just throw them out in 1919??

Wow,
This burst of information was very interesting to me!! Thank so much. I wonder how many of these still survive? Mine has a brass base with no markings. The glass bead that holds the filements is marked in black pen or something. One side says TB1,and the other side has a 4 digit number. Maybe, a serial number? The bulb is crystal clear.



Andy

Andy,
Lots of early tubes manufactured by GE lamp works had the markings on the press. I have a few UV-200's and UV-201's with the same. I have a VT-14 that also has the markings.

Hi,
I am kind of amazed that the tube number (TB1) looks to be etched,or sand blasted on the glass!



Andy

GE used "Kenotron" name for its line of high voltage low current rectifiers at least thru the 50s. Mostly in X-ray related equipment.