{"id":32482,"date":"2018-05-30T08:40:13","date_gmt":"2018-05-30T12:40:13","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=32482"},"modified":"2018-05-30T08:40:13","modified_gmt":"2018-05-30T12:40:13","slug":"how-to-build-sm0vpos-20-meter-magnetic-loop-antenna","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2018\/05\/how-to-build-sm0vpos-20-meter-magnetic-loop-antenna\/","title":{"rendered":"How to build SM0VPO’s 20 meter magnetic loop antenna"},"content":{"rendered":"
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The completed 20 meter loop antenna.<\/p><\/div>\n

A few days ago, SWLing Post contributor, Robert Gulley (AK3Q)<\/a>, pointed me to an excellent website by Harry Lythall (SM0VPO<\/a>) which is chock-full of various homebrew radio projects. In particular, we both were impressed with Harry’s 20 Meter Loop Antenna–it’s such a simple project and requires no special order components. In fact, all of the components (save, perhaps, the antenna connector) can be purchased at a DIY store.<\/em><\/p>\n

I reached out to Harry and he has kindly allowed me to republish this project as a guest post:<\/em><\/p>\n

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20m Loop Antenna<\/h1>\n

by Harry Lythall – SM0VPO<\/strong><\/p>\n

Introduction<\/h2>\n

I recently saw that my 80m (3.5MHz)\u00a0loop (or frame) antenna<\/a>\u00a0has been really popular, and that there are loads of other radio amateurs who have taken my design and\u00a0“ran with it”<\/i>\u00a0to produce variations that all have some great improvement. There have been many in-depth tests and simulations, all with exceedingly good results and reports. This is exactly what I am aiming for with my homepages – free information for all and my designs being improved upon. That way we all win \ud83d\ude42<\/p>\n

One small point all variations have in common is the need for an expensive tuning capacitor and a very restricted RF power level. Of course, you can throw money at the problem, but for me this hurts. I got to thinking that there must be a way of adjusting the design a little and finding another technique to tune the antenna, and to make the best use of the little radio transceiver I have in Sweden, given the limited space.<\/p>\n

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My limited space apartment.<\/p><\/div>\n

As you can see there is not much opportunity for grand antennas. And to add to this, the equipment I have in Sweden is also limited to a single 5-Watt unit.<\/p>\n

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My limited equipment – only 5-Watts.<\/p><\/div>\n

The Design Thoughts<\/h2>\n

Today I have no area of land to use for antennas. I have a glassed-in balcony on the 4th floor of an apartment block. I really like the 20m (14MHz) band so I will concentrate on that. I am not really interested in the CW end of the band, except perhaps 14.070MHz for the digimodes. So my requirements are:<\/p>\n