[Milsurplus] R-720 AN/URH-2 ??

[Nick England]

Here is what I sent the original poster:

Well that is an odd one! The XN-1 indicates it is the first prototype of
the AN/URH-2 but you never know whether they made any more or just the
prototypes. I'll guess it is for recording and mapping out signal strength
of Navy VLF transmitters. It could be the sort of thing they'd take all
over the globe, recording the daytime/nighttime signal levels so they'd
know where they had adequate coverage for transmitting to submarines.
But that is just a guess based on the frequency range and panel markings.

Aha! Some clues.
Pickard and Burns developed a VLF navigation system for Polaris submarines
and this may have been used for testing during that development.
"Draco is a moderately accurate VLF navigation system developed bv Pickard
and Burns which operates at long range. It has the advantage of being a
"secure" navigation system in that it can utilize standard VLF
transmissions to obtain navigation references, and can operate while the
submarine is submerged."
See this page for some info on the Pickard and Burns development and
measurement work.
http://jproc.ca/hyperbolic/omega.html

Pickard & Burns was later involved in the development of the Omega
navigation system and this may have been used in experiments concerning
that.

Nick England K4NYW
www.navy-radio.com

On Tue, May 1, 2018 at 7:30 PM Hubert Miller <Kargo_cult at msn.com> wrote:

> This oddity showed up on Antiqueadio.com forum :
>
> http://antiqueradios.com/forums/viewtopic.php?f=5&t=339838
>
>
>
> So what's this about?
>
> --
Nick England K4NYW
www.navy-radio.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20180501/2cabbd8e/attachment.html>