Interesting part

From: Tom Jennings <tomj_at_wps.com>
Date: Mon Jun 14 13:56:02 2004

On Sat, 2004-06-12 at 12:08, Patrick Finnegan wrote:
> It was a Delay Line, part number
> > ADL-CN037. I forgot who the manufacturer was, but it was someone big
> > and established (GE maybe)?
> >
> > Anyone know what this is?
>
> Probably just a "standard" mercury delay line.

They are only "lumped constant" delay lines, generally inductors and
capacitors, that delay a pulse, usually no more than a few microseconds.
They contain no mercury, just coils and capacitors. They're usually
small, like .5" x .5" x 4" plus or minus a factor of 4.

They're pretty common in older surplus, and have little value (unless
you need one :-)

> Some early machines used large versions as their primary storage, they
> functioned somewhat like a (more) solid-state drum memory.

Columns of mercury were used as computer memory for a short time, but
they were ACOUSTIC, not electrical, data storage. They are large,
cumbersome, expensive, toxic and valuable, there's a relatively small
(few hundred lbs) of Hg related junk and a rack or two of support logic.
The chances of finding a computer mercury delay line memory are slim
these days.

They originated in WWII radar, where they were used to remember the last
received signal pass, so they could detect differences with the current
signal pass, and cancel out stuff that didn't change.
Received on Mon Jun 14 2004 - 13:56:02 BST