[Elecraft] K3 receive on .474.2 kHz

[Edward R Cole]

Emory,

First off receiving a station at 597km  (370mi) is not a bad distance 
on 474 KHz.  Most propagation is ground wave which does not extend as 
far as HF.  Best propagation is in winter and at night when a little 
sky wave is seen.

Where have you searched for antenna info?  Try this:
http://www.500kc.com/

Most on 160m and 600m know that vertical antennas work best.  Your 
double length G5RV probably is something like 30 or 40 feet 
high.  That is equivalent to hanging a 10-foot long dipole 1-foot off 
the ground for 20m.  Short horizontal antennas do not work well on 600m.

True that a full size 1/4 wave is a little high (492-feet) so you are 
stuck with very short antennas which have very low impedance until 
you use a top hat and loading coil.  Short antennas are capacitive so 
a big loading coil at the ground end connected to a ground rod is a 
common solution.  Top hats also make the antenna appear 
longer.  Inverted-L and Marconi-T are two typed of loaded vertical 
antennas.  Typical antenna for non-directional beacons running 
300-500 KHz are about 300-foot long and 60-foot above ground with a 
single vertical wire from the mid-point down the beacon transmitter 
sitting on ground.  My inverted-L is only 43-foot high and 122-foot 
long on top.  I have a large base coil at the ground end 10-inch 
diameter 11-inches long with 1/4 inch winding spacing.  I tap the 
coil two turns above the ground end to feed coax to the shack.  My 
antenna efficiency is less than 1% because of its size.

For receiving there are magnetic loops, pendants (triangular loops), 
and beverage antennas (if you have some acreage).
The farthest I have copied signals is Buffalo, NY which is over 4000 
mi.  But that is the exception.  Normal day-to-day range is out to 
300mi using ground wave.

I can't really tell you much in a paragraph or two.  You can join a 
600m e-mail list at the above website if you are really interested in 600m.

73, Ed - KL7UW, WD2XSH/45

Date: Sun, 22 Feb 2015 18:37:13 -0500
From: <ejkkjh at gmail.com>
To: <elecraft at mailman.qth.net>
Subject: [Elecraft] K3 receive on .474.2 kHz
Message-ID: <DB8C4DBB35F44F3BB99C3E532D258663 at ejhPC>
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After the install of the new KSYN3A synthesizer board, I tried WSPR 
on 474.2 KHz, using double size G5RV for receive.
I am able to copy WG2XKA using WSPR, at 597 km.
I did some web searching for antennas, only thing I found were 160 ft 
verticals, not an option for me.
Anyone know of a wire antenna or something easier to put up?  thanks and 73
Emory WM3M


73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
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