Question about vacuum tubes

[EmuGamer]

Hello everyone! I am hoping somone can help me determine the value / functionality of a tube I got today.

It's a Eimac electronics 2-450A (13 in tall, 5 in wide) It has never been used, and the glass is 100% clear.

Brand: Eimac electronics 2-450A { usa }13 inches tall
Here is my problem, when I removed the packaging the vacuum tube appeared to be in perfect condition, however I could hear something making a slight rattling noise when I turned the tube from right side up to upside down, and vice versa (similar to when a light bulb burns out).

Upon closer examination I could see two very thin wires approximately one inch long and a few nanometers wide that have broke loose inside the vacuum tube.


I have no way to test the tube yet, and I was planning on building either a HAM radio or stereo amp out of it in the near future as a project.


Anyway if anyone could give me an idea if this indicates that it is broken or possibly has a shortend life span I would greatly appreciate any ideas.

[yajnaS]

a few nanometers wide ?

they're probably from the grid.

[Alastair E]

Prob pieces of heater....

Check continuity, prob find its O/C....

At the high volts those tubes run at, there should be nothing floating round loose inside!

[HollowState]

Originally Posted by EmuGamer

Hello everyone! I am hoping somone can help me determine the value / functionality of a tube I got today.

It's a Eimac electronics 2-450A (13 in tall, 5 in wide) It has never been used, and the glass is 100% clear.

Upon closer examination I could see two very thin wires approximately one inch long and a few nanometers wide that have broke loose inside the vacuum tube.

Your Eimac 2-450A is a high voltage, high vacuum rectifier. It was designed to replace two parallel 2-240A's in three phase power supplies. There is no grid, so the loose wires you see rolling around inside are from the filament which is broken. They are somewhat rare since they're long out of production. Unfortunately it has no commercial value anymore and now makes only an interesting collectable. (I have one in my collection)

PIV: 30KV
DCI: 1A
Peak I: 8A
Plate Diss: 450W
Fil V: 7.5V
Fil I: 25-28A
Socket: Johnson#124-214

[Richard Ellis]

A few nanometers wide? WOW! Do you have Superman vision or what! Please, if you dont know your measurement values dont be throwing them out willy nilly......kinda looks like you dont know what your talking about. OK?

__________________________________________________ ____Rick........

[Gilgy]

Originally Posted by Richard Ellis

A few nanometers wide? WOW! Do you have Superman vision or what! Please, if you dont know your measurement values dont be throwing them out willy nilly......kinda looks like you dont know what your talking about. OK?

__________________________________________________ ____Rick........

Well that was harsh.

I just assumed that he was more accustomed to the imperial rather than metric system. Nanometres, millimetres, easy mistake to make.

[Frank Berry]

It was a very thin wire.
Not sure why such a wire would be in a tube that handles so much power.
Certainly not a part of the 200+ watt filament.

[v4lve lover]

no **** but for something running at 7.5 volts 28 amps your heater isnt going to be thicker than say 0.7 mill as any thicker and it would require a welding transformer to heat it

[HollowState]

Originally Posted by Frank Berry

Certainly not a part of the 200+ watt filament.

Without digging mine out to look at it, my memory says that the filament is multiple strands of fine wire. Thoriated tungsten actually. This was pretty common design back in the day. (still is) There's nothing else inside that it could be except for the supporting structure which is much thicker.

[EmuGamer]

So it's probobly in a non-functionl state now with the broken pieces I take it? From the sounds of it I guess it could have never really been made into anything besides a display piece correct?

Thanks alot for the information everyone!