Thursday, December 30, 2010

An inverted V dipole for 30 metres

Signal strengths on the 30 metres band using my Butternut multi-band antenna don't seem to be as good as those on, say, 20 metres and 40 metres. So I took it into my head that I should construct a dipole for 30 metres. And, with my limited space, I immediately knew it would have to be a so-called "inverted V" variety. For the uninitiated, that's basically a wire antenna in the shape of an upside-down V!! Simple eh?

When I rang Tony EI4DIB, my "rigger" as Pat EI2HX likes to call him, and explained what I'd like to do, I could tell Tony was instantly fascinated and excited by the whole plan. While Tony doesn't do much HF himself, he loves setting up antennas for other operators, and does so with great enthusiasm and energy. He gets great joy out of seeing other operators get on the air, or get better radiation than before!

And so the plan was hatched. But there was one catch. Tony asked the question: "What materials do you have for this dipole?"

"Erm," came the hesitant reply. There followed a lot of head scratching on the part of EI2KC and soon I said with excitement, "I have wire!!!"

"Do you have coax?" he asked. "No," came the reply. "Do you have plugs?" he asked. "No," I said again, solemnly. The whole plan was beginning to look decidedly dodgy. "Do you have a dipole centre?" he asked. "Erm, no, sorry," says I.

Thinking the whole dipole idea was "out the window" as they say, I was surprised when Tony interjected, "Not to worry. I have a dipole centre, some coax and some plugs that you can 'borrow'."

He's good like that. So good, in fact, that Pat also calls him my "sponsor". Too right Pat, but Tony likes to be paid with plentiful coffee and sticky buns. Next time I'm in the home bakery I'm going to buy a whole tray of sticky buns for my rigger, Tony.

We got to work yesterday, Wednesday, and soon had the makings of a decent dipole. I used reconstituted wire from my old half-size G5RV. Glad to be putting RF through that wire again, I can tell you. It was my first proper HF antenna. We took the pole supporting my longwire down and attached the dipole and soon we were getting the leg lengths right. It's not perfectly flat on 10.115 where I wanted it to be resonant but it's a decent job and nothing the tuner won't flatten in a jiffy.

A test over the last 24 hours has proved that it is better than the Butternut, although only marginally. In most cases signals are about an S point or maybe two stronger than the vertical. Last night I could hear Australia VK on the inverted V although he was very weak. I couldn't hear him on the Butternut. I wasn't able to work him, however, because he had a big EU pile-up calling him. But nonetheless it proved that the antenna installation was a success and it did what it was supposed to do - to improve my RX on that band. And this morning, just to prove it's really working, I had a QSO with JL1QOC on the new V. And to top it all off I worked a SV9 (Crete) on 30 metres which was a new country on that band, bringing my total countries worked on 30 to 93. Just seven off the big century now. Hopefully Tony's latest installation at my QTH will help me get over the line.

Hopefully I will grab a photo or two tomorrow and put them on here to show you our excellent work. Thanks again Tony. I'm sorry to say I've lost count of how many sticky buns I owe you . . . !!

3 comments:

  1. Hi Anthony, that sounds like a true homebrew sucess story. Just goes to show how both building stuff and friends in amateur radio are truely alive in 2010! 73 DE Mike M0SAZ (amiga600.net)

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  2. Where would you be without Tony EI4DIB and his expertise?
    Indeed where would a lot of us be without his help and his skills, indeed there would be quite a few without the antennas erected that they have now.
    I think you owe him a lot of sticky buns and coffee!!!!

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  3. Hmmmmm......Sticky Buns...Nice!!!

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