[Milsurplus] Question ( RBS; submarine )

[Nick England]

"It has been reported", .... but I don't know where -

>From http://www.tubedevices.net/Lorenz.php
"It has been reported that a German raider during WWII indeed managed to
locate merchant ships sailing on their own, not in convoy, by direction
finding on the signal radiated by their receivers. Presumably, these ships
had rather old-fashioned equipment, perhaps with an oscillating detector
directly coupled to the antenna."

Certainly NRL and USN training documents say that the purpose of shielding
and RF and stages was to prevent LO radiation that could be tracked by
enemy ships. The NRL history states this rationale for the RAA, RAK, RAL,
etc. designs, well before it could have been invented as a "cover story"
for Ultra, etc. So it seems there was certainly the belief that it was
possible.

I'm not so hot to dismiss this as myth or misdirection - The middle of the
Atlantic in 1942 must have been pretty damn quiet RF-wise. (Unimaginably
quiet compared to my house.)  And an oscillator connected to a nice long
wire high above a steel ship in a salt water ocean is not to be sneezed at.

Current QRP efforts have shown 500+ mile reception on 80m with a 40
microwatt transmitter.
Here's some 100mw 500kc results - http://www.w4dex.com/medfer.htm

Nick England K4NYW
www.navy-radio.com

On Thu, Aug 25, 2016 at 10:31 AM, Ray Fantini <RAFANTINI at salisbury.edu>
wrote:

> Can anyone anywhere document just one example of active LO direction
> finding in use by any Navy in WW2? , I am not talking about DF operations
> in fixing locations of submarines or surface craft by receiving low to
> medium powered CW or AM transmissions, or the practice of receiving radar
> emissions to identify frequencies and pulse rates but the alleged practice
> of attempting to receive the LO of a receiver at any distance beyond a
> hundred feet.
>
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