[Boatanchors] Old active image intensifier tube

[J. Forster]

Steve Uhrig wrote:

> I guess not all boat anchors are radios.
>
> A friend sent this:
>
> > Steve, in going through my collection of "stuff too good to throw away
> > just yet" I came across a Farnsworth 1P25 vacuum tube (the main
> > element in one of the WW II night vision devices) -- in original
> > packing, plus a data sheet I got from GE in the mid-1950s.  Its serial
> > number (written in pencil on the box) is H 53 72.
>
> > If this sort of thing is of any interest to you at all, or if you know
> > of some museum or collector who has an interest in early surveilance
> > hardware, I would be happy to send it to you..
>
> =========
>
> If anyone might have an interest in this, please strobe me and I'll get
> you in touch with him. I imagine from the part number it's a small CRT.
>
> Steve WA3SWS

It's NOT a CRT. It has a photocathode, electron lens, and phosphor screen. In
the 70s Meshna and Edmund were getting about $10 for them. The input and output
faces are not flat, so special optics are needed. It takes about 5 KV DC plus a
focus voltage at very minimal current. It converts visible 800 to 900 nm IR to
green light.
-John