Ham Radio: Make Your EFHW Into a DX Machine!

The EFHW is a very adaptable antenna as we can configure it in so many ways. By doing this as a half square we can make the harmonically related bands perform really well for DX!

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[beemcbike]

It‘s my favorite antenna. Use it only on 15 and 10 m. Have fed it both ways, but prefer it lower corner and 49:1.
One thing you didn’t talk about is noise. Where I live I had about a S 4 noise level and with the half square it’s gone. It’s worth trying guys!
Thanks for your work de HB3XBL 👍🇨🇭

[mikebeall]

Hi Tim, I put a cord on the end furthest away from the transformer and pull it out horizontal for 40m as an inverted L, when I want 20m and above, loosen the cord and the sinker returns to the bottom and back to the ½ square.
VK6MB

[abrahamnorthhampton]

This is such an informative video, Tim. Every time I see one of your videos, I come away saying, " Oh, I need to try that this week!" My XYL isn't as enthusiastic as I am, but hasn't yet demanded that I stop. 73 from America!

[garrywalker]

Made one this last week. If works very well and low SWR at all the right places. Also stealth and pivotable to give directionality.

[vumes]

Long back I had an antenna like this which was distroyed in a cyclone. Right now i have an efhw and I am trying this conversion. Sharing to our group. Thanks 🙏 73

[GDDX]

Thanks Tim, built one as described and working really well, especially on 15/10m.

[Davidm-MTPT]

Nice one Tim i use this antenna fed from the corner and 10-15-20-40 and 80 it really is a Machine :)

[oldfartonabmx]

Thanks for your videos! I hope to get my hfkits efhw up over the next few weeks. (Straight line at this stage) Going to use 6 meter, 50mm pvc pipe (guyed) to get it a good height above the metal shed and house roof.

[Coyotes_Locos]

I'm running a 130 ft. 10 in. 80M-10m EFHW as an inverted V with the feed end at 5 ft. above the ground, the center at 25 ft. and the far end at 10 ft. above ground. SWR on 10M is about 1.2, near flat across 12, 15, 17, 20, and 40M. SWR on 80M is about 1.5 at the tuned frequency. From south-central Colorado, in a valley between mountain ranges, with 100 watts, my furthest contacts are to United Arab Emirates, New Zealand, Russia, and to Australia. I also use EFHWs for POTA. Marty, WT0Z.

[billygamer]

The Half Square works very well. I have used the form on the 80 meter Band with good results compared to an 80-10m band ground plane monopole vertical mounted over tuned radials.

You can imagine that the 80m version might be quite high, needing 20 meters of height plus head-height clearance. Having only 15 meters of height available, the lower end of each vertical element was bent inward toward its opposite. The antenna then looked similar to an 'omega' symbol. Since current is greatest at the driven end of a vertical element, this made little difference to radiation.

I used the antenna when serving as net control for a nightly 80m phone net working stations from coast to coast to coast in Canada with me at the centre. According to signal reports from stations more than a couple of hundred miles from me, the antenna was superior to my 80-10 meter vertical except when working northern stations at right angles to the preferred radiation directions. Then the omni-directional monopole was better. Closer in stations saw no difference between my monopole and the Half Square. On receive, there was an improvement in received SNR using the Half Square compared to the monopole since the Half Square is bi-directional.

I also built two Half Squares for the 20m Band with each at right angles to the other allowing me to switch between East-West and North-South patterns. I did not use the pair long enough in order to draw conclusions worth passing on.

Give the Half Square a try!

[joebidet]

Those are awesome
Simple
Vertical polarisation
Low angle
2 1/4 Vertical
4 db gain over one Vertical
No ground radials
12 db broadside to end null
Just use current bslun 1 to 1 at one of top corners
I will put one up for 40m to europe

I avoid radials

Its 1 wave total
1/4 1/2 1/4

I think dipole null is about 8 db depending on height

[portants]

Nice video as usual, but the titles above the azimuth/elevation plots at 3:40 and 6:25 are misleading, you're certainly looking at a 20-odd meter length of wire, but the antenna is a half-wave on 40 meters, so the titles should state that this is for a *40-meter band antenna* . The titles are confusing, giving wire length as opposed to band - it's important to not confuse the viewer. YMMV, of course...

[PostingNotes]

Hi Tim, another great video, a question, would there be any advantage ( in gain) on 20/15/10 meters if a half wave on 80 meters was used?

[junkpuddle]

Brilliant antenna I use one portable now and again on 20m and managed zl on it from the UK. M0cql

[malchaschwatrz]

Well done. Well explained..What about a half wave end fed (for 80 meters)in an L configuration 50 or so feet vertical, 80 or so feet horizotnal, fed with 49:1 unun ? Pattern on various bands please?

[gpen]

I tim the half square fed at the bottom With 49.1 is the other end of the transformer earthed or would a counterpoise be better
Thanks Bob G4PEN

[paulbyrne]

Have you used this antenna in the field? As Peter said earlier, have you used this type of antenna and do you have a video of it in actual use?

[arthurgumbus]

I have a 75-10 M EFHW configured in a flat configuration from 35 feet at the feed one end and 55 feet at the far end (the land slopes away from the feed end) using a hefty 49:1 Balun coax fed with LMR400.. It is a great antenna for DX. However it is a bit more noisy than my 80-10 M Horizontal Loop. Will reconfiguring it with the 1/4 wave vertical sections at both ends even make it more noisy? Usually, you do not GET something without GIVING something up.... the NO FREE LUNCH rule of antennas... I wonder if any of you who have experimented with the 1/4 wave V 1/2 wave H and 1/4 wave V config can share their experiences on 20, 17, 15 and 10 meter bands. Thanks Art W1SWL

[ronaldcphotography]

Would it make a difference if 49:1 was up a meter on pole, the element up 5m. Total pole height 6m. Or does 49:1 need to be right at bottom of pole ? Thanks

[petertompkinson]

Very interesting vlog there Tim! Have you built this or is this just theoretical modelling? Be good to see it as a photo in the flesh.