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Receive Antennas (below 30MHz) - For all topics related to receive antennas used on HF, MW, LW, etc. For transmit antennas use the Amateur Radio Antennas forum.

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Old 07-27-2017, 10:53 AM
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Default large aperture mag loop antenna

Those of you living in urban settings with tiny lots, this should be right up your alley (so to speak)

Video: Paul’s large aperture “Volleyball Net” magnetic loop antenna | The SWLing Post

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Last edited by ka3jjz; 07-27-2017 at 10:59 AM..
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Old 07-27-2017, 7:44 PM
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Nice yard and 'home built' antenna. The speaker stands are just like the Pyle stand available at Home Depot.
I wounder what that antenna would with another couple of turns?
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Old 11-21-2017, 10:33 PM
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That's very close to what I use in limited space areas, although mine is a bit different. It *looks* like a loop but is really an inverted-u.

Imagine limited space using the edge of a patio awning only 8 feet tall, but 16 feet wide near the backyard grass. Very similar to the support structure in that video.

Coax feedline on the ground runs over to one edge of the non-conductive awning.

Wire connects to center conductor, run vertically 8 feet, then horizontally 16 feet, and then back down on the other side of the awning, but only 7 feet down since I don't want the far end actually touching ground.

At the feedpoint, add radial(s). If you can, and it is safe from foot traffic, run the radial on the ground underneath the overhead horizontal portion of the antenna, but do not attach it to the far end hanging down. No closed loop. Depending on the area, that might be the only radial you can run.

If you really look at it, the common-mode of the coax feedline is one radial too really. You may want to choke it either at the feedpoint, or actually use the common mode and choke it near the shack. Experiment. More radials, like all verticals, improves efficiency but sometimes one is all you can do.

The first casual glance if you do this makes one think it is a loop, but it really is an inverted-u fed at one end and the other end NOT touching ground or anything else.

Use your choice of matching. Manual or automatic tuner or at the least, a 4:1 or 9:1 UNUN (important, NOT a balun!) and a short run of feedline (or very expensive high quality long one) should be used.

Generally, the 1:2 ratio of vertical to horizontal provides the most usable radiation angles, (in this case 8 feet for both vertical portions, and 16 feet for the total horizontal), but of course actual frequencies in use along with environment can change things. If I had the space, I'd run 16 feet up, 32 feet horizontal, and then 15 feet down (so as not to touch the ground). Small variations in vertical and horizontal runs aren't *that* critical.

The small sized inverted-U has been my favorite limited space choice of HF antenna for a few years now. Keep expectations realistic if you are transmitting on the low hf bands, but this may be just one other option to consider too for rx-only installations.

Last edited by hertzian; 11-21-2017 at 10:45 PM..
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Old 11-21-2017, 11:19 PM
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Here's something of a variation of Hertzian's theme, supposedly good for tropical band work. As we're getting close to winter here in the US, this one might be very interesting...

EWE Antenna review :: DXing.info

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