[Milsurplus] Tube ID ?

[Kenneth G. Gordon]

On 15 Jan 2018 at 14:24, Bruce Gentry wrote:

> 
> I wonder if it is an 805.  Amperex  made a fair number of industrial  tubes with their own 
> numbering system.

It is not an 805. 805 is a single-ended tube. Grid connection is in the base.

However, it MAY be an 810, which does have the grid connection on the side.

The filament voltage for either the 805 or the 810 is 10 V. I think the 810's filament current is 
4.5 amps.

Depending on the physical size of that tube (which is not clear from the photo) I am betting 
that it is an 810 or something very similar to it.

In any case, the filament glow at 5 V indicates to me that the correct voltage is 10 V. The 
filament should be a bright white, not that reddish glow. 

If it is an 810 or equivalent, the filament is a thoriated-tungsten type.

Ken W7EKB

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