Horizontal Loop Antenna Experiments

Man-made RF noise levels have increased dramatically at my place in the past six months. It has become much harder to hear weaker shortwave signals. Even the stronger stations are getting covered in all types of hash from all manner of electrical appliances.

So, I have been looking at ways to reduce the noise problem. I’m currently researching a few possible solutions, including trying a different antenna.

The HF horizontal loop has been around for many years now, but it’s a new antenna for me. I’ve never had a need to try one…..until now! There is some documentation out there praising this antenna’s low noise capabilities. So, it was time to find out for myself and start building an experimental version. So far, the results have been really quite pleasing!

I have prepared a YouTube video (below) in which I discuss the reasons for looking at this antenna, its design, and its installation. I also do some on-air comparisons of my experimental rectangular (!) version of the horizontal loop against my three regular double bazooka (coax) dipoles and the Par SWL End-Fed antenna.

Have you tried this antenna before? Your thoughts and feedback would be most appreciated.

73 and good DX to you all,

Rob VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

Spread the radio love

5 thoughts on “Horizontal Loop Antenna Experiments

  1. Mark Duncan

    Hi Rob, What type (electrically speaking) is the 4:1 Balun you use here?
    It is a isolation type where primary and secondary are galvanically isolated for example?
    Also, do you use a common mode choke with this antenna too?

    Regards
    Mark

    Reply
  2. Ian Baines

    The horizontal loop is fairly common for 80 m you have the space, as it radiates vertically which is ideal for NVIS. For short distance communications on 80, 60 and 40 the high radiation angle and lower noise really do work. Many hams also use a vertical loop, as it provides a lower angle of radiation. Regardless of orientation, the loop is lower noise as it is much less sensitive to the electrical component of the radio wave, which tends to predominate in the short ranges that typically cause RF interference. Like the noisy power supply, LED light or TV that your neighbour owns.

    From a practical point of view, I have not found that the shape matters that much. I have built deltas, rectangles and squares. Whatever will fit. And a low loop works quite well, if you can’t get it way up in the air. If you have trees, the loop can run between them in any configuration that allows you to keep the wire hidden from those nosey neighbours. The only thing that i would emphasize is that you need to use a balun to prevent pickup on the coax cable feeeding the loop. A 4:1 balun is common, but for listening a 1:1 works well. You can wind your own on a toroid if you search Google for how they work. 73

    Reply
  3. DanH

    I put up a 83 meter horizontal loop earlier this summer for SW listening. The idea was to use as much of the perimeter around my suburban lot as possible. It’s my best antenna so far with improvement in signal to noise over the long wire antennas. The loop isn’t magic when it comes to man-made noise, though. It still picks up plenty of tropical band RFI from one of my neighbor’s electronics. It’s a good antenna for the AM broadcast band, too. Here is nice reception of BBC World Service on the loop.
    https://youtu.be/MKWfFj63GUw

    Reply
  4. Thomas

    You’re using one of my favorite antenna designs, Rob! I love horizontal loops.

    I first discovered them in 2004 when I moved into a neighborhood with decent RFI and nosey neighbors. 🙂 There were no official HOA rules to prevent me putting up an antenna, but my closest neighbor made it clear that ham radio antennas were not welcome.

    Two ham buddies (Eric WD8RIF and Mike K8RAT) visited for a weekend to help erect an antenna and get me back on HF. I wanted one multi-band stealthy antenna. Mike suggested the horizontal loop. With three of us on the job, erecting it was fairly painless.

    We essentially strung the antenna up under the cloak of darkness–in other words, we carefully watched for any nosey neighbors. No one saw us erect the antenna and the side facing the road had no insulators or feedline visible. The feedline (ladderline) was hidden behind my house and fed the loop in a spot not visible by neighbors.

    That antenna was absolutely amazing. It naturally mitigated RFI and no one in the neighborhood ever noticed it! The side of the delta loop facing the road was quite visible, but it turns out no one pays attention to a relatively thin wire with sky blue jacketing 50′ above their heads!

    I worked some serious DX with that antenna.

    When I moved to my new QTH in 2011, a horizontal delta loop was the first antenna I put up. It still serves me quite well!

    Thanks for the post, Rob!

    Reply
    1. Rob Wagner Post author

      Thanks for your comments and the story of your early experiences with the horizontal loop, Thomas. Very interesting. Quite a few people have used H loops, it seems, except me. Which makes me laugh!….I’ve been involved with radio for more than 45 years now and had all sorts of antennas over that time, but I’m only just getting around to H loops NOW! What’s that saying about old dogs and new tricks?

      I might be wrong, but I have a feeling that the shape of the loop is not too critical. So I suspect that many people could probably fit one into their own properties without too much trouble. But, obviously, this is not an antenna for apartment dwellers.

      There’s some more experimentation needed on this. I’ll let everyone know how it goes in future updates. Cheers, Thomas.

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.