Topband: Balun or no balun

[W7RF Dan]

Kirk,

I put up a large horizontal loop and can use it just about everywhere but since I have a Yagi for 20-6M, the loop gets used primarily on 160-30M.
The loop I put up is about 1100 feet of wire in a square up 65 feet (supported by four 70 foot utility poles I planted in my field) fed with about 220 feet of 450 ohm window line. The 1100 feet amount of wire was chosen more based on what I could fit but I wanted about 2 wavelengths on 160M. It works VERY well for DX on 80-40-30M and depending on wave angles, can work very well for DX on 160M. Stateside signals on 160-30M are very good as well. I worked FT5ZM on Amsterdam on 160M and I had a time window of about 20 minutes in my morning with signals up to 4 S units out of the noise, no headphones needed!
There are many mechanical considerations when using a feedpoint that is not supported but floating (I use a pulley system to raise and lower each corner).
I bring it back to the shack horizontally supported by PVC topped 10 foot TV mast. Then right where it enters my shack through a board pinched by the sliding window, I use RG-213 for about 5 feet to get through the wood and not to worry about unbalancing the parallel conductors as it is near metals in the window frame, etc.
To do this, I use the center conductors of the coax as each leg of the feedline and ground the shields at the tuner but leave the shields open where it meets the 450 ohm feedline. I use simple banana plugs/jacks at that outside junction to quickly disconnect for lightning.
I tune it with a Palstar BT-1500A true balanced line tuner.

I hope this gives you some food for thought showing how one Ham did it. On 80M results are sometimes better, sometimes worse than my full size 80M vertical, depending on what DX I'm working.
It has been said by many "once you put up a loop, you never take it down".

If you are feeding it with 30 feet of 450 ohm window line that means it will not be up very high so I would expect your DX results would be limited on 160 and 80M.

Undoubtedly there will be opinions but I can tell you that this configuration works incredibly well for me.

73, Dan W7RF
www.radiodan.com
Fort Collins, CO


Message: 6
Date: Tue, 11 Nov 2014 04:46:56 GMT
From: W3AW via Topband<topband at contesting.com>
To:topband at contesting.com  <topband at contesting.com>
Subject: Topband: Balun or no balun
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I have put up a 160 meter horizontal loop fed with 30 feet of 450 ohm feed line to my tuner.  I have a Radioworks 4 to 1 balun. I am considering splicing into the feed line at 10 feet so I can run 20 feet of  coax into the shack.  Thoughts?  I run a qrp plus on 160.

Kirk
W3AW
Illinois

-- 
73, Dan W7RF
www.radiodan.com