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Tuesday, May 16, 2023

Building another YU7EF duoband antenna (3)

  
   Slow progress is made. I wish I had this antenna ready before the ES season. But unfortunately it takes time to build and time is a precious thing. I can't help experimenting with this design as well. I had no angle aluminium to mount on the boom to fit the (6m) dipole elements on. So I thought of angled weather resistant plastic. Side effect is that it probabely prevents disturbance from the boom. I really don't know how much and of course I don't know how this plastic behaves over time. I decided to take the risk. The material is also used for cladding on buildings.












Of course this gave me a mechanical challenge. The plastic looks solid but it isn't. The outside is solid 1mm thick plastic but the inside is a kind of foam. When you mount it on the boom with the bolts and nuts, like I did, the long end will move downward along with the pressure of the nuts. I needed to invent something to push it back to a straight position. I used tiny pieces of angled aluminium for that and bend it up a little. It worked out very well so far. I could nicely tune the plastic parts till they were flat with the boom.

When writing this post I just thought about the plastic foam. I think I need to protect the sides with a rubber like coating. I have some liquid gasket material in stock. I think that would be perfect.


Update 18-5-2023

I abandon this experimental plastic dipole mount. I tried it today but it did not work out like I had thought. Searching for angled aluminium thick enough to use now.

2 comments:

  1. Good morning Bas, very nice and professional looking job on the antenna. When making something from scratch it always seems that with each new idea or plan come a line up of challenges. Very good idea with the brackets for support. We have here liquid rubber tape which I use for many applications around the shack.
    Looks good and waiting to see updates and how in the end it works.
    73,
    Mike
    VE9KK

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  2. Tnx for the comment Mike. This is a antenna build for PB7Z Bernard. He's about 50km south of me. I will not have it in my tower myself. But have made one before and that one is working very well. ES season is already there and I should have my VHF beam into the tower soon. And finish this one for Bernard. See his tower here: https://cdn-bio.qrz.com/z/pb7z/IMG_20220629_114240_727.jpg. He is currently using a 3 element version. 73, Bas

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Thanks for your comment. Bedankt voor je reactie. 73, Bas