[Milsurplus] LF, VLF, ELF, SLF, and DC

[gl4d21a at juno.com]

----- Original Message ----- 
From: "Bob W7AVK" <rsrolfne at atnet.net>

> Hank - Years ago in the early 1970s I had the opportunity to visit 
"Jim 
> Creek" one of the Navy's million watt ELF stations located north east 
of 
> Seattle between two mountain tops.
=+++++++++++++++++++
Hue adds:

I saw this in a book "Antennas" by  Lamont Blake, re NLK at Jim 
Creek,
Washington state, 24 kHz:  
"This flat top is a conductor suspended between two mountains over a 
mile apart, and the vertical portion is close to 1000 feet in height". 
If you scale that up to say, 2400 kHz, like in the old marine band, it
would be a mast antenna 10 ft. high, with a top hat 25+ feet on each side
of mast top. With 1 000 000 watts into this, you'd probably get some 
signal reports too, altho you couldn't work to underwater.
The Army's BC-611 used a whip about 3 foot long on 80 meters. If we're
right in understanding the German WW2 vehicles "pipe rack" or roof-
antennas, the vertical portion was ONLY about 1 foot tall, and this at
frequencies down to the 1 MHz range. YIPES!   
-Hue Miller
+++++++++++++

OK, now consider the now defunct and removed Omega system.  Operated around 10 to 14 kHz, and also had flat-top antennas strung between mountains.  The only one I ever saw was on Oahu, and it was too large to really get any visual perspective of.  Ran megawatts there also, but disappeared without a whimper.  Big civil engineering task to get those antennas up, equally as challenging to get them down.  I was over there a couple of months after the Hawaii station was removed, and I could not find one Ham or Navy radioman who could tell me about seeing it taken down.  Couldn't turn up any Coast Guard personnel, who were actually in charge of the station.  One person said he *thought* he remembered seeing something about it in the newspaper.  

On the ELF frequency question, I recently reviewed an old EMC Conference document which happened to contain a paper which referred to the (then) proposed Navy ELF system as being in the 40 to 70 Hz range.  Yup, same as power line frequencies.

73,
George
W5VPQ



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