I built a loop a few months ago, using flexible plastic pipe strap and 1/2" copper foil tape with conductive adhesive. I used a junkbox air-gap capacitor and a 10x vernier knob to tune it. I ran 100w through it on FT8 and ran an infrared thermometer all around it and it barely warmed past room temperature. From inside my house in the Philly burbs, I got FT8 contacts in northern Wisconsin and Fargo, North Dakota on 30 meters, so I think it was getting out pretty well. I was running 30 watts or so on it at the time, as I recall. Not bad from indoors on the first floor with a steel workbench a foot away and resting on a wire rack. Someday I'll take it on a park run and see how well it works out in the open. I'm considering making a better loop first though, as this one is pretty flimsy and probably won't stand up to any significant wind. I need to redesign it for more rigidity and probably a somewhat larger loop to get at least SOME efficiency on 40 meters and perhaps even a little on 75/80, though that's asking a lot of a small loop.
73, Gwen, NG3P On Thu, Jun 6, 2019 at 12:11 PM Edward R Cole <[email protected]> wrote: > Interesting reviews on some of the loop antennas. I've seen W4OP > adv's for several years. > > I plan to make a receive-only 630m loop (4 to 6 foot diam) out of > some surplus 1/2-inch hardline that is too old for coax use. The > copper shield should do well in a loop. I will use a preamp with it > (pcb in hand waiting for some spare time to build). Plan using a > small TV rotator and tripod mount. Advantage of the loop is being > able to null out noise sources. I transmit using 43x122 foot inverted-L. > > The loop might also work for 160m if I ever try that band. > > 73, Ed - KL7UW > http://www.kl7uw.com > Dubus-NA Business mail: > [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > -- -+-+-+-+- Jenny Everywhere's Infinite: Quark Time http://quarktime.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
