[Elecraft] K3S ELF 10KHz

[Fred Jensen]

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
>