Tube identification time

[Proschuno]

So I've had these tubes for a while now and can't identify them, googling every nook and cranny. These seem like beam power tubes given their size, and they do glow, but I can't get them to operate normally with the supply I have now; I'm sure they operate at almost 1,000v, while my supply will only pump 450ish.

http://twitpic.com/photos/Proschuno

[Geek]

My guess is an 845:
http://tdsl.duncanamps.com/show.php?des=845

[kheper]

Is the base brass or bakelite?

203-A GOOD FILAMENT HIGH GRADE 211

http://www.ebay.com/itm/1-EARLY-BRASS-B ... 7675.l2557

[Geek]

*looks at structure at top*

203, of course

[EWBrown]

http://frank.pocnet.net/sheets/049/2/203A.pdf

Looks like a brass base, hopefully these 203As are not gassy, like the pair of WE276As that I had.

They'd flash over at 450-500 VDC on the plate .

/ed B

[kheper]

Proschuno: These tubes are run at 900-1100Vdc. This level of voltage is dare-devil/insano territory. If you don't want to build an amp with these tubes and they test good, you should be able to make some dough on ebay.

You can run them at normal voltages, but they will get no more output wattage than any other triode run at the same voltage, plus they are rumored to sound thin at lower voltage.

[Proschuno]

So to answer some questions, they do have brass bases, and I was able to crank more volts out of my supply, and got a faint bluish glow. Is this a 'gassy' tube?

[EWBrown]

If the blue glow is on the inside of the glass envelope, then that is OK, if it is inside the plate, then it is gassy.

Sometimes, the gas can be reduced or burned off just by running the filament for a few hours, at normal voltage.

My gassy 276As had a greenish glow starting at about 450V, then they would flash over, above 500VDC.

/ed B