NLK[?] at Jim Creek used to transmit on 24.8 KHz with a megawatt or a
little more. I don't know if it is still active. The antenna is [was]
a linear series of vertical elements down a valley, suspended by cables
from the mountains on each side. I believe there were ten total, fed in
two groups of 5 from two transmission lines on the valley floor. The
suspension cables provided capacitive top loading, most of the radiation
came from the vertical elements. Similar to the antenna at SAQ.
Not much to listen to, it was [or still is] extreme QRSS. Just a
handful of characters, often only one or two.
The Omega system operated down in the 10-15 KHz range. The NA station
was in one of the Dakotas, but it's been decommissioned for several
decades. It wasn't much to listen to either. WWVL was on 20 KHz for
awhile, gone now, and not much to listen to when it was on. I've
"heard" WWVB on 60 KHz, pretty dull.
At frequencies below 20 KHz, you don't need tubes or transistors, just a
generator with a lot of poles and high RPM. Before LORAN-C on 100 KHz
died, at least one of the stations was outfitted with an Accufix
transmitter from Megapulse Corp. This was a late 20th Century
re-incarnation of the spark gap TX ... SCR's for the spark gap, huge
capacitor banks, around a megawatt, and precise timing from a room full
of electronics. What goes around sometimes comes around.
73,
Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn
On 3/23/2017 3:45 PM, Ron D'Eau Claire wrote:
The Jim Creek antenna facility is amazing - a series of over mile long wires
(cables) for the radiator strung from mountain to mountain across a valley
being fed with IIRC a megawatt of VLF RF.
73, Ron AC7AC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
