Big old tube!

[tiktok]

Saw this in a museum this past week. Hard to make out the scale from this picture, but it looked to be about 8-10 inches tall!:

[6942]

Dat nuttin'!

You should have seen the size of the tubes we used in our little (for a radio station) 2000 watt transmitter back in the early 70's.
We used a "dead-mans stick" to ground it before servicing.

Steve

[Tremo]

Transmitting tubes of yesteryear can get pretty big. Glass tubes only get so big then they become too fragile, so they then go to metal/ceramic. Then liquid cooling.

For certain microwave electron beam type tubes, the gun end is submerged in a tank of oil to prevent arcing, and since it's running at 150,000 volts, it has to be run in a 1/2 inch thick lead walled booth to shield people from the hard-ass x-rays it produces. I saw the results of one that lost focus, the beam drilled (melted) a 1/2 inch hole clear through the side of the thing.

A friend of mine built a PFN power supply for one that produced megavolt pulses. Everything was in oil.

[FMA]

All I can add is I can't wait to see what kind of amp Johnny Crash builds with one of those things...

[65flh5326]

This metal cutting lathe uses 2 c16j thyratron tubes about that size. They are still made at $1500 retail each!
They power a 5hp DC motor, unsurpassed performance, the machine will go from 0 to 4000 rpm in under 2 seconds.
http://s170.photobucket.com/albums/u...ent=Don006.jpg

[mojo2001]

That tube ain't nothing.....doesn't even have handles.

Tubes get much much bigger than that little thing.

[telesavant]

Tubes do get large....here's a tube from a Navy destroyer...Radar room I think, with a 6L6 shown for scale.

[Tremo]

I think some of the biggest glass tubes are those with about 1000 watts plate dissipation. Much above that they get too big for glass and run too hot.

Tubes with 20,000 watt plate dissipation usually use liquid cooling.