MERC Meeting 20201113 - VK5SFA Magnetic Loop Presentation
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- Опубліковано 18 лис 2020
- Our third remote presenter, Steve VK55SFA, on his famous 160m double magnetic loop antenna.
Further information on Steve's antenna can be found at members.iinet.net.au/~sadler@n...
Still figuring out Zoom's idiosyncracies - we have Steve's talking head to the right of most of this, and a rogue's gallery in the first couple of minutes. We're getting there, and hope to do better next time.
Hi, I'm in my 70's & in a wheelchair, I'm a disabled Vietnam combat Vet.
I got my Novice license at age 10
I built my first station from Old TV chassis' given to me from a TV shop as payment for sweeping their parking lot & cleaning out the mess that was under their bench. I hand wound all my coils, later went in Army & was a radio repairman for about 4 years doing component level repairs, then switched to Bio-medical
Thank you sir for YOUR SERVICES
"Death by PowerPoint" 🤣🤣🤣
I am getting ready to start building 2 of them. I hope to get them done over the winter! We have been collecting parts for 6 months now thanks for the design and all the documentation.
Wonderful presentation! Thanks! "The concrete that was holding in the supporting post was drying four hours later..." 😃
Interesting presentation thanks for your efforts.
Hi Steve,
Just wondering if you have information on calculating the overall length of coax loop, the spacing between each turn of the loop and also the size of the small feed loop?
.thanks
Hi, Is it possible you could explain to me your point at 17 minutes 15 seconds. All I can see is a plastic support at the end. Can you explain what you’re referring to as regard to the commutator
I'm very impressed with your results! this is a very motivational project. Good Job! 73's from Brasil
Hi, thank you for the wonderful explanation and the presentation of the loop Antenna. Can you tell me if there is a way of calculating what size the small loop has to be in relation to the size of the main loop.? Is it a percentage or a calculation, I also noticed on the six meter loop there was no small second loop and I would really like the measurements you have for that too.
Best regards 73 M0UHF
Спасибо! Ваша информация на 100%.
У мена магнитная антенна с 2019 года. Периметр 260 см, медная трубка диаметр 20мм, самодельный конденсатор, бабочка, 7-120пф. Согласующая петля по схеме DK5CZ. Диапазон 14-30мгц. Стоит на балконе, есть QSO со всеми континентами, мощность использую 100 Вт. Доволен.
73! de TOLY UN9PI tnx.
Is there any reason why the variable tuning capacitor cannot be located at *ANY* point around the loop? I don't see why it must always be located diametrically opposite the feed point. Perhaps the tuning capacitor could be located even right next to the feed point?
If the tuning capacitor is located diametrically opposite the feed point, *both* sides of the capacitor are "hot" to RF. But if it is located close to the feed point then only *one* side of the capacitor is "hot" to RF. Perhaps this might make tuning easier?
Does the diameter of the pipe matter / what is the smallest dia
Hi. Would you be able to help me with calculations of some measurements? I have 25feet of heliax for the build. Is it enough, or should I shorten it to make it work like yours. Thanks.
His used a bit over 75 feet, so you don't have any where near enough for a 160m loop. 25 feet will make you a very efficient loop on 30m, and still work well on 40m, and even get you on 60m.
I would think these antennas are a nightmare for the ARRL's new RF exposure guidelines.
Super info - great stuff. 73 de GI8WFA,
Hi Steve today I just build one for 80 meters wow my 5 watts I was a s9 20 kilometres from my qth again wow. I to do same more testing 😃👍👍👍👍
Very impressed with your loop. My homebrew loops are quite small compared to yours. Would love for you to check out diy bike wheel loop I made. Love your video lots of info. M6yik fran
Instead of a double loop, what about a triple or quadruple loop ? 73
If that antenna works, in reality anything works as an antenna, even the elastic of the bed, what is different in all antennas is its performance, for a magnetic ring antenna to be efficient it must cover area, that is, the fact of That it has to have two turns or more and make up for its lack of perimeter with capacity makes it an efficient antenna, and even more so in the 160 meter band, the experiment is laudable but it will not go very far. si esa antena funciona, en realidad cualquier cosa funciona como antena, hasta el elastico de la cama, lo que es distinta en todas las antenas es su rendimiento, para que una antena de aro magnetico sea eficiente debe cubrir area, o sea el echo de que tenga que tener dos espiras o mas y suplir su falta de perimetro con capacidad ya la hace una antena ineficiente, y mas en la banda de 160 metros, loable el experimento pero no va a llegar muy lejos