• [PE4BAS] Concept antenna concept

    From PE4BAS via rec.radio.amateur.modera@21:1/5 to All on Fri Oct 1 08:08:46 2021
    XPost: rec.radio.amateur.moderated

    PE4BAS Amateur Radio Weblog

    ///////////////////////////////////////////
    Concept antenna concept

    Posted: 28 Sep 2021 12:53 PM PDT https://pe4bas.blogspot.com/2021/09/concept-antenna-concept.html


    Another concept antenna or is it an antenna concept? Previously tried quarter wave wires direct on my antenna with less success. Couldn't get a
    good SWR on 12m and 10m with the ATU. I even tried to attach quarter wave
    wires as counterpoise instead of my tower. Then I did read some articles
    that multiband dipole antenna wires should at least be separate 10cm from
    each other to minimize the interaction. Another challenge is to make
    quarter wave radiators the right length. Measuring is no option since I
    always use an ATU at the feedpoint. So I calculated some wire lengths and
    made a practical experience wild guess. Counterpoise is again my tower. You
    can see this whole thing as a massive OCF vertical dipole with a ATU in the feedpoint. I also keep my wide band 1:1 balun between the antenna and
    tuner, not shure if this helps? A 1:4 balun could be a better choice?
    Since I had to remove the duoband 6m/4m beam for the winter I decided that
    it was time for another antenna experiment.

    Somewhere on the internet I saw a video from someone that had a nice idea
    to separate the quarter wave wires. So I lend the idea to implement on my
    own vertical as experiment. The secret to build this thing is "shockcord"
    to keep the wires straight under all circumstances. I ordered 20m from it
    on the internet. The only wire I could not attach shockcord was the 4,9m
    long wire for 20m since the antenna is basically too short, but I don't see that as a big problem.


    If you think this is a strange contraption....look at our sunflower...

    Last time I counted it had 12 flowers in it. And it grows wildly.
    You can see the results I have with this antenna and 100W RTTY in the
    previous post. Not that it is always the antenna that gives good results
    since we all depend on propagation. But I'm very satisfied with it so far.
    SWR is good on all 5 bands I designed it for. I measured it with the
    IC-7300 and took some pictures. I will publish that in a separate post
    since I found some strange behaviour on my IC-7300 measuring SWR on 10m
    above 28.500 MHz.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)