[Milsurplus] SRR-11 GI users, info please?

[Richard Brunner]

Re:
">> Think most or all subs had these to receive VLF attention-getters fm 
Jim Creek then.  While undersea.  .....    My question relates to background 
noise arising from rf-input.  Did it drop materially when the sub 
submerged?"

Somewhat germaine to the question, I remember a letter to the editor, in the 
Lowdown I think, from a guy who was in the Kriegsmarine.  He reported good 
reception sitting on the bottom of the Atlantic off New England, off New 
York City, and in the Gulf of Mexico, in about 100 feet of water. (From 
memory - can't find it now.  Their official records show 8 to 26 M. deep for 
reception at New York.)  The antenna was a small loop insulated with rubber 
so the salt water wouldn't short it.  German transmissions were 15 to 60 Kc. 
from Goliath at 900 Kilowatts maximum.  Extrapolating, that means that the 
ulf signals at 40-70 cycles used now are probably detectable at depths of 
thousands of feet.  We know that signals attenuate with depth, so logically 
ambient noise would go down too.

Richard Brunner, AA1P