Hello to All,
I have just acquired a box of tubes from a cousin who got them from his work, they were going to be thrown out.
I use radio and amplifier tubes and have never seen these tube types. I'm guessing they are transmitting tubes?
If anyone can enlighten me to the use or type of these tubes it would help satisfy my curiosity, I don't have a use for them but thought they would make a cool display.
Thanks for any info,
Mauro

You have it right. They are transmitting tubes. Often used in the RF output stage of an amateur transmitter.

Here is information on 5D22, the number seen in your photo:

https://frank.pocnet.net/sheets/140/5/5D22.pdf

Greetings to Mauro and the Forum:

Yes, those are all transmitting tubes. The one on the far left looks like a 304TL. That is a high power triode for MF or HF work. The next one could be a 4-400 or something similar. A high power tetrode for HF work; if it is a 4-400, the plate dissipation rating is given by the last part of the number. The four means four elements; the four hundred is 400 watts plate dissipation. The Penta Labs tube is their version of a 4-250 (4 elements meaning tetrode; 250 watts plate dissipation). The last tube is an older tube; I'm sure someone will recognize it, but I do not off the top of my head.

Regards,

the last tube looks a bit like a VT-4 / 211.

Greetings to Mike and the Forum:

The last tube does indeed look like a 211 (envelope shape and brass base) but I am pretty sure that a 211 does not have a plate cap.

Regards,

The 5D22 is missing the ground ring. It may still work fine
without it, however. It should look like the 2nd tube from
the left, which looks like a 4-400A type. It's also been
robbed of its plate cap- again, it should look like the
2nd tube. It would not be difficult to get hold of one- just
scavenge one from a known bad 'dud' tube. The 3rd tube
is also known as a 4-250A BTW.

David

In the instance of the high power tubes, lacking a transmitter to test them in, I wonder if the manufacturers offered any sort of testing service for their high power tubes back in the day? I guess some of the very high power tubes could be rebuilt back then. For commercial users. Big transmitting tubes from unknown sources are pretty much display items for most people. Unless they are new old stock or known good, and you have a project in mind.... You will need a pretty hefty power supply just to light the filaments, on most of them.

The tube at the right end is a Type 805. Base is marked as such.

Norman

They did not. Transmitter tubes are tested by seeing how they operate in a transmitter.

The transmitter tubes that can be rebuilt have metal-ceramic envelopes, not glass envelopes.

Dale H. Cook, Radio Contract Engineer, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcityeng/index.html

Thank you for all the information.
I guess I have some new display items.
A great weekend to all,
Mauro

The 5D22 may have gone to air, or hopefully it is just dusty. The 304TL tube may have a bad filament. You can check the specs and ohm it out with a meter.

If the white deposit is inside the tube, it's a dud.

That style tube was usually not flash gettered, the plate was impregnated with a gettering agent.