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.
5 comments:
Wow! You’re a proper experimenter Bas! Looks like lots of fun.
73, Tom, M7MCQ
Hoi Bas. Mooi gedaan hoor. Maar wat is er met je hand die op de eerste foto zichtbaar is? Beetje rare kleur...
Hallo Jan, tja....dat is niet mijn hand. Dat is een handschoen! 73, Bas
You never know until you try - like that time with my 160m ground loop antenna and a confirmed JA QSO on fairly low power! I hope the winds aren't too strong this year! Propagation, for sure, is considerably improved at higher HF now.
Hello John, this antenna is an experiment and not build to last. It probabely breaks at the first big storm. But is doesn't matter. I already have other projects in mind ;-) ;-). 73, Bas
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