Posted by: GW7AAV | January 28, 2010

New Yagi designs from G4COM

I see from Southgate ARC news that Derek G4CQM is looking to publicise his antenna designs. He has done an update to his website with several new antenna designs. The designs are fairly simple to construct and all the details are available for free on the website. Lionel VE7BQH has provided performance analysis tables that show how well the antennas should work.

The only issue I have with Derek’s designs are that he insists on using Netlon clips to mount the elements. Netlon clips are designed to hold garden netting for climbing plants or shading. The problem is that the clips are held in place by a single bolt, which means that over time the elements move out of line and eventually spin like helicopter blades in the wind. Still as radio amateurs we tend to adapt other peoples designs rather than follow them to the letter so I don’t see it as too much of a problem, unless of course you buy one of Derek’s kits.

Edit: I was wrong about the Netlon clips. See Derek’s comment bellow

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Responses

  1. Steve,

    You are completely wrong about the Netlon clips. Netlons have TWO holes. One hole in the spine and one under the jaw that holds the element. In our kits we use TWO self-tapping screws to secure the clips to the boom. This STOPS ROTATION period!

    Back in 1994 I purchased a huge quantity of Netlons direct from Netlon Sentinel. Large numbers have been in use since on 2M and 70CM yagis, they have proven to be very effective holding the elements. Users include experts such as Christopher Bartram GW4DGU and Ian White GM3SEK.

    I sincerely hope that you will now correct your statement!

    Regards, Derek Hilleard G4CQM

    • My appologies to Derek, thanks for putting me right on that one. I can only imagine that the clips I bought(years ago)when I first saw them used were either a slightly different design or from another manufacturer. They certainly looked the same but came with a woodscrew that I replaced with a stainless steel bolt.

      Regards Steve GW7AAV


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