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Topband: Waller Loop

To: TopBand List <topband@contesting.com>
Subject: Topband: Waller Loop
From: David Cole <g3rcq@yahoo.co.uk>
Reply-to: David Cole <g3rcq@yahoo.co.uk>
Date: Thu, 3 Sep 2015 19:33:33 +0000 (UTC)
List-post: <topband@contesting.com">mailto:topband@contesting.com>
I have built a Waller Loop to the dimension from information on the internet, 
the loop is vertical and mounted on a tower at 30 foot. My problem is I cannot 
get any front to back. I have rewound the transformers and made two phasing 
lines - all show now difference, I checked the 180 degree phase shift with my 
scope by feeding the AIM 2180 constant signal. All looks good.
I then decided to build a second Waller Loop using all non metallic tubing - 
excellent all works fine and very acceptable front to back. On the second 
working loop I replaced the support pole with aluminum - no change and still 
excellent front to back.My only conclusion now is that the two loops are 
coupled by the 26 foot aluminum boom. I have sufficient size and strength glass 
fiber pole which I intend fitting in the center of the current boom, this will 
put a distance of 7 feet between the boom ends and hopefully reduce any 
coupling. Has anyone had any experience similar to my self and if so what is 
the answer?My test to prove the front to back was to beam both loops at 300 
degrees, the forward gain in the receive path was equal - however the 
difference when looking at stations of the back was from S7/8 on the no F/B 
loop to in the noise on the working loop. I am sure, as I am so involved, I am 
missing something help!! Dave g3rcq 

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