Thursday, December 3, 2009

A small measure of success on my delta loop

I had some measure of success with my improvised Delta Loop for 80 metres last night, although only after a significant modification. I had a brainwave yesterday while reading a webpage about unusual items used as antennas. Someone had, apparently successfully, used the bed springs from a mattress to radiate RF on the HF bands. Someone else mentioned that using a chicken wire fence or a large metallic object as a ground plane can be quite effective.

Bing! - the light came on in my head.

Up to now my triangular-shaped delta loop consists of a total of about 50 metres of wire, strung around the garden not as far enough off the ground as I'd like. One end of the antenna is connected to the coax inner, while the other end is connected to the braid. There is a coil at the far end made of about 50 turns around 2" uPVC piping.

So I figured I would earth the "far end" of the loop, and run a separate wire from the braid of the coax onto the roof of my garden shed, which is made of metal. I was delighted to find it tuned up on 80m, right up to the top and right down to the bottom of the band. I was unable to test it until very late last night because I was at the Dundalk club meeting.

After midnight I worked two Echo India stations, one in Laois and the other in Cork, and both gave me good reports. They were both 59 with me. Later I got a contact in Germany, although with QSB he was having trouble hearing me at times.

Then this morning I was delighted to work Lima Alpha, a station inside the Arctic Circle in Norway. I'm delighted to be up and running on 80m, although without the proper height off the ground that I really need I can't expect to be doing too much DX. However, it is good to be up and running on 80m because the action on 40m has been quite limited in the past week or so. And 20m is only active while I am at work!!

I will post one or two photos of my Delta Loop when I get the chance.

Yesterday I also carried out an experiment using an abandoned clothes horse from the house. Yes, you read it right. I'm talking about those things you put clothes on to try. This one is made of aluminium and coated in plastic. I stripped back some of the plastic, and connected the coax inner to it, and the braid to the shed roof. I was able to tune on 80m and radiate RF. Tony EI4DIB gave me 59+20, but that was no true test of the "Clothes Horse Antenna" because he only lives a mile from me. I might do further testing in coming nights!!

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