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Topband: Loop Antenna

To: <topband@contesting.com>
Subject: Topband: Loop Antenna
From: dcbc@ipa.net (Dan)
Date: Sat, 9 Nov 2002 11:11:18 -0600
Hello All
I am trying to finish my 5BDXCC and need better preformance on 80 as well as
chasing DX on 160.
I need some advice.
I put up a loop antenna in the trees on my property.
Loop is about 300 feet of wire.
Top of loop is about 50 feet bottom of loop is about 10 feet in height.
I am feeding the loop at one of the bottom corners close to the ground.
At the feed point I have wound a 30 turn choke coil on a 4 inch diameter pvc
pipe close spaced turns.
It just doesnt seem to be working as good as i thought it would.
This antenna is closer to 80 meters but will it work on 160 meters?
Would it help if I raised the feed point up to the middle of one side ?
I am sure there is some feed line swr loss as i am feeding it with 50 ohm
coax.
Will it preform better if I change to open wire feed line?
If I need to use open wire feed line I need to either build a balanced tuner
or use the tuner i have with the ferrite balun built in.
I cant see how a ferrite balun on the output of a tuner is any good as a
ferrite wants a feed line close to its impedance. I have been told that a
ferrite balun wants to see a low swr or will have lots of losses.
I hope i have givin enough info for some help here is my questions
1 Will this loop work on 160 meters?
2 For better performance on 80 and 160 meters do I need to move the feed
point up to the middle of the vertical section ?
3 For best performance is it best to feed with open wire line. ( I have
never used open wire line )
4 If I need open wire feedline. Is it ok to use the tuner I have with the
ferrite balun or should I build a balanced tuner ? I have an amp with 1500
wats output.
5 If it is not good to use the tuner with the ferrite balun then where can i
purchase a balanced tuner or where can i get the coils prewound. I remember
coils they called mini ductors.
Any help would be most welcome.

Thanks
Dan W0VD
w0vd@arrl.net
www.clevengercreations.com/w0vd.htm


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