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[TowerTalk] Question for loop users

To: <>
Subject: [TowerTalk] Question for loop users
From: "Jerry Connelly" <>
Reply-to: Jerry Connelly <>
Date: Sun, 9 Nov 2003 13:16:16 -0500
List-post: <>
Hello all
I finally got my 80m loop up yesterday.  I used the ARRL antenna handbook's
"loop skywire" design.  Wire is 272' for resonance at 3.7 mhz and fed with 450
ohm ladderline about 1' off a corner.  Height is low (30') but that was the 
I could go with the trees available.  Its a start anyway.  Maby I can improve 
that later.
I'm using a Yaesu ft920, 3' coaxial jumper to manual tuner, 6 or 12' coaxial 
jumper to
a 4-1 current type remote balun (Radio Works),  then ladderline to loop.  I am 
a balanced tuner to replace the manual tuner and the remote balun and allow me 
to run
amp occasionally when I can afford the rest of the components I need.

I'm very pleased with most aspects of it.   Its much quiter than my old dipole 
seems to have considerable gain on 40m and up.  75m is even to a some better 
the old dipole except for the quiet noise level.  I really like the quiet.  It 
will tune 160m
and the old dipole wouldn't.  My first three contacts were on 160m and I got 
fairly good
signal reports ranging from s9 to 10 over.  That me smile.  

Here are the questions.
I cut the wire for 3.7 thinking that the loop would be closer to resonance on 
40m and up 
rather than cutting it for my real area of interest (3.85 to 3.95).  I did it 
this way on advice
of another loop user but he feeds his with a very short length of coax and 
lives for cw. 
Is this correct or should I trim for my area of interest on the lowest band 
(3.9 mhz) and let
the tuner take care of the higher bands???  

My ft920's auto internal tuner handles the 40m and up with a push of the button 
but balks some
on 75m or 160m.  The internal tuner will find a match but not using the on 
touch memory tune (says
high swr).  I understand that on 160m but 75m should be in range of the tuner 
unless the wire length
or feedline length is a problem.  
My feedline (ladderline) is somewhere between 118 and 125' long and thats close 
to a half wave length on 75m.
I can remove a little or add more by routing the feedline.  Any suggestions 
about how much I need
to trim/add to get the tuner working properly.  It does tune fine on the manual 
mfj tuner but I think it has more
mismatch range.  

Thanks in advance


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