Thursday, September 7, 2017

More magnetic loop experiments

Experimenting is the main thing of this hobby I think. So, my goal this time is to make a usable small portable magnetic loop that is reasonable easy to tune. There are several designs that you can find on the internet and some of them claim to be better then others. I choose the coax version for myself as it is light to carry and can be very small. I discussed some possebilities with PE1BVQ Hans and he gave me the measurements of his own loop that does well. I already had the 3x 500pF varco from him and decided to use it again but in a bigger box. The problem of tuning still is very difficult and Hans told me I should build a reduction. Glad the box is big enough.... I first thought of building another varco myself but let that go eventually. I have the luck to have a colleague that happens to be also studing for mechanical engineer and he always has good ideas. He designed a reduction system with isolation (less handeffect) from scrap and some new parts. The idea is simple but effective, this guy has nothing with my radio hobby but though of the exact good solution within 5 minutes. I think that is incredible! And besides that he helped to realize the mechanical part. We finally build this together and tuning is now a lot easier.

But still I would like to have a indicator besides the indication at the tuning knob. It should be no problem, but that is another experiment. Now, I was thinking of were to really use this antenna in case of emergency. And just when I was thinking this video shows up:


Of course you use it inside a shelter. I would use it in the basement as that is the most safe place in the house when disasters like hurricanes will happen. When my loop is ready I will test it for shure and post a video, at least that is the idea...

8 comments:

  1. Hallo Bas, leuk verhaal over de experimenten. De vertraging ziet er goed en simpel uit. Belangrijkste is dat hij vertraagd zodat de afstemming niet zo kritisch is. Ik ben aan het uitpluizen of er een indicator te maken is zodat je op max signaal kunt afstemmen. Een simpele SWR meter, zo klein en simpel mogelijk. Voor een EndFed bestaat al een toroid met spoel en ledje. Wordt vervolgt. 73 Hans, PE1BVQ

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    1. Hallo Hans zoek eens hier: https://rsars.files.wordpress.com/2013/01/qrp-loop-tuner-80-20m-g8ode-iss-1-32.pdf
      Zo een toroid met led geprobeerd maar werkt niet op een magnetic loop. LED gaat wel aan maar op verkeerde moment. Er moet een stroom meter gemaakt worden. 73, Bas

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  2. Hallo Bas, zo'n collega is nooit weg. Goed idee. Loops vind ik wel fijne antennes. Als ik ooit kleiner ga (moet) wonen dan zal ik zeker overstappen op een Mag. loop. Ik ben benieuwd naar je experimenten. 73 Paul

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    1. Hallo Paul, gisteren snel getest in de pauze hier. Maakte onverwacht een QSO met PSK31 naar OK. Had ik niet verwacht, signalen waren best wel goed. 73, Bas

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  3. Excellent! There are lots of ideas on tuning out there, but being western men (mostly), the solutions we come up with are often extraordinarily complex, expensive and impractical. Tuning is easier than people say with magloops, but a simple reduction drive like that is precisely what is needed for most of us!

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    1. The problem is the brain gets lazy with all the gear you can buy on the internet. Sometimes it as easy as this. 73, Bas

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  4. Great video , I've made a mag loop and after this video am hoping it works as well as yours .
    Ian Holdford ( England ) 2e0duu ....club G1RAF .

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  5. I hope the magloop works weel Ian. Tnx for your comment. 73, Bas

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