[Lowfer] Medfer TX loop findings so far

Sun, 17 Feb 2002 21:40:12 -0600

Just have Dex give you field readings. It probably is better having him in a
fixed location so far away. I guess you would call these far field readings.
Thanks for sharing your findings on the cable. Now I won't repeat that
experiment. I was thinking of trying that before you told us it doesn't work
worth a darn. Let us know how the multi #14 works out. I have been thinking
of that since the big Litz wire is hard to find in surplus and a joke to buy
new.

Mike>WE0H
http://www.geocities.com/we0h/index.html

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Brian Helms
Sent: Sunday, February 17, 2002 9:07 PM
To: [email protected]
Subject: [Lowfer] Medfer TX loop findings so far

I put up a Tx loop measuring 3 meters per side this weekend and I tried to
use some shielded cable that I had scrounged.  The cable was 8 conductor and
was about .5 to .75 inches in diameter and I thought it would work great due
to surface area of the wire.  After getting the loop resonated I called Dex
to give me a signal report since he is only about 6 miles from the house.
The signal was so weak he could barely make it out in argo.  Last year when
I had a vertical up for Medfer frequencies Dex could copy me at 0dbm into
the antenna.  I replaced the shielded cable with a single run of #14 copper
wire and it improved the signal by at least 10 db and brought my signal well
above the noise at Dex's house.  This was kind of surprising to me but it
did teach me a lesson about using different kind of wire for the loop and
that just because it may have a large surface area doesn't mean that it will
work well for a loop.  Bill had it right on when he said that the shield may
or may not be a good conductor.  Anyway I will be adding more wires in
parallel with the single #14 conductor that I have on the loop now so I will
keep you posted.  The loop is around 5 feet off of the ground as rjeloop
program shows no appreciable gain above this but I am going to try to raise
the loop in the future to see what kind of improvement it makes.  I have no
current measurements or field stregnth readings as of yet because I do not
have an rf ammeter or capability of measuring field stregnth but I am
working on it.

73's

Brian Helms
KD4RLD
www.qsl.net/kd4rld

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