HAM RADIO: Loop Antenna 80 metres to 10 metres

Thanks again to Rick, DJ0IP for publishing details of this antenna which he says provides great gain at higher angles for 80 and 40 metres as well as very good gain 20 metres through 10 metres. Let’s use MMANA-gal modelling to see if this agrees.

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[MrFreddarama]

I had a very large horizontal loop that was made for 500 Khz at my property on the beach of Maui. I could hear shipboard CW operators at night across the Pacific and would tune up this loop for 160, 80, and 40 meters where it had a lot of gain. It was one of the best multiband antennas I ever had. These days I have a 160m horizontal loop at 45 ft fed with 450 ohm line and to a 4-1 balun and short section of coax. It works good but is nothing like the monster loop I had years ago. Great memories.

[NebukedNezzer]

I have been using this antenna for 35 years. works great.

[jerrymoyer]

I have used an 80m loop as my primary HF antenna for about 10 years now using trees as supports, and I agree with everything presented here. I originally started using a loop because of a noise issue originating with an AM broadcast station antenna array on 1300 KHz only 900' away. The 3rd harmonic was broad and nasty until I changed over to the loop. Having a balanced antenna also solved the problem of getting a good RF ground on the 2nd floor of a house. It was no longer required! I moved away from the 1300 KHz station several years ago and now feed it with about 100' of LMR400 coax. While not ideal, the loss is not terrible. I had aesthetic issues with the XYL using 450 ohm. My noise level at the new location is S1 or less. The loop is only 6 t0 10 meters off the ground yet I can still work 40 meters into Canada from Oklahoma with a hundred watts no problem. 30 to 10 meter band performance is superb as well.

[richardwesterman]

Well done (again), Tim. For clarification on the name: there are two kinds of loops, vertical and horizontal. Because this horizontal loop is laying down, I call it a "Lazy Loop".

Due to changes in my employment, I moved around a lot. I introduced this loop to three different clubs. Each club was using a tri-band beam or quad, plus dipoles for 80 and 40 at Field Day.

There are 4 major lobes and by proper orientation (here in Germany), with the strongest lobe pointed at stateside (NW), the SW lobe was pointing long path to VK, the NE was pointing to JA, the SW to the Middle East.

Besides blowing the dipoles out of the water on 40 and 80m, the loop held its own against the beam (or quad) on the high bands, at least in its 4 main direction. As a result, all 3 clubs ceased bringing a tower and beam to field day and just used the Lazy Loop on all bands. This gave us more time for Bratwurst and Beer.

73, de Rick, DJ0IP

[davidc]

It's a good design, but keep in mind loops can be just about any shape, so don't think a square or delta is all one has to choose from. Whatever shape fits in the yard or attic will work.

[geoffreylotz]

I had a 160m horizontal loop back in ZS, fed with homebrewed 450 Ohm feedline from a 4:1 balun and a short length of RG213 to the shack. My experience with that version convinced me to build an 80m version for my new QTH in wire antenna I ever had. I will be supporting it with four 12m Spiderbeam heavy duty telescopic masts and a longer feedline to feed the Northeast corner, hopefully allowing me to contact my mates in ZS with my 100W on a good day. Thanks for the MMANA analysis of this antenna, I have been wanting to see such an analysis. Thanks for the video and for the time and effort to make, edit and upload. Much appreciated. 73 CT7/ZR1XZ.

[davidryeburn]

Here's a way you may be able to get around the high SWR losses on 160 m. Open up the corner opposite the feed corner. Then (a) put a relay there to reconnect the two wires when desired. You'll want it open for 160 m and closed for higher frequencies. On 160 m with the relay open you've got a badly bent up half-wave dipole which should have a very low input impedance. Alternatively (b) at that far corner instead of a relay, connect to an additional length of ladder line 1/4 wave long at about 1750 kHz, shorted at its far end. That will present an open circuit to that corner outside the low end of 160 m at 1750 kHz, and inside the band will put a capacitive reactance across the open end of the loop detuning things to an even lower resonant frequency, but it still should work. On 80 m, 40 m, 20 m, 15 m, and 10 m the shorted ladder line stub will be an integer multiple of 1/2 wave long and will present a short to the corner of the loop causing the loop to behave pretty much the same as the original design on those bands. All bets are off on the non-harmonically related WARC bands with the stub, but with the relay they'll be like they are in your original design.

Now to get this to work correctly you're going to have to set the resonance point of the stub at the low end, 1750 kHz or thereabouts and everything should be fine for CW. Shorten the stub a bit to get it to work nicely on 75 m for 'phone operators and the harmonic resonances are all going to be way off, so good-bye 40 m and higher. Thus this trick is only going to be useful for us CW operators.

David VE7EZM and AF7BZ

[timbacchus]

This is what I have been using for 25 years. Has never required maintenance Feed it with 800 watts and has a four clover leaf pattern on 20 of which I use the most.

[ycnsi]

Thanks for the great Video! For many years I have installed a 165 meters long wire antenna on my property and across my neighbour’s house.. It is also known as a skyloop antenna and the feed line is an old tv antenna twin lead about ten meters long onto a 4:1 home made Balun in the shack.. Then it is connected by a short coax to an mfj tuner.. Works reasonably well on all the band including 160 meters for CW n FT-8 including the WARC bands.. 73 de YB0NSI..

[Dave-VKPL]

I had one of these in the 1980s, but it was only about 4m high. It worked great on 80 to most of Australia (I'm in VK5). With our Novice licence I only had 2 other bands 15m & 10m and I made lots of DX contacts.

[EiiP]

2.5:1 balun is what I've used in the past, with great success 👍

[wmps]

I had an 80 meter full wave loop which I used for years. Best wire antenna I’ve ever built. Was at about 40 feet high, fed with 450 ohm ladder line with a 4:1 balun near my operating position. Internal tuner of my FTdx1200 handled the rest. I had to do some ladder line trimming to get it operating on all bands. Great DX results. I fed it in the middle of one leg (just a convenient spot).

[alzeNL]

thank you so much for this excellent video tim. Whilst I wont do this in the QTH, I will go back to this video for my next field day with my local amateur radio society (G4PRS). Whilst 80m is always awesome, seeing the gain on 17M I was roaring with joy ! Out in the field with an IC705 and this setup for QRP but with the space and setup requirements, this is a lovely project to do on a field day. I cannot wait ! 73 2E0FWE

[OllieVK]

I discussed this with Callum from DX Commander a little while back, he had a better solution:
"You build 2 x wavelengths for 40m and get it tuning.. Then near the tail of one end of the loops, build a loop of wire about 12 feet long (4m) and droop it from the feedpoint and connect it to the loop in a long arc (almost half a circle) then when 80m comes long, it'll try and use that too, forcing the resonant frequency lower (and should wide-band it slightly..)"

[baslev]

Modelling this with MMNANA is nice but everything is pure theory. Everything depends on the surroundings like buildings, trees etc.. I've had this antenna for years built around my garden. I've worked much DX on 80m. It is useless on 160m. It is also useless on 10m (and 12m) if you compare it to a 1/2 wave vertical or a simple 2 element beam (those will do much better). But it is a great antenna from 80-15m especially around the greyline when DX signals can be on high angles as well. Of course it is a excellent NVIS antenna. I had a lot of fun with it for years. Changed it now to a 2x20m doublet since my XYL didn't want the loop around the garden anymore. Personally I think the doublet is doing just as good as the loop. 73, Bas PE4BAS

[joeblow]

Great video, cheers from the other side of the pond

[baikushexet]

Greetings from kyrgyzstan 🇰🇬
I think this is what I'll put up on the building I live
4 6m masts will put it 27m above ground
Building is 24m x 24m
Very noisy here in city
Hopefully a loop will lower qrm qrn
Also will use it for mw dxing as well
Love Building and listening to crystal radios
Thanks for video

[peteride-kostic]

I build the same Antenna but for 40M not 80M. It works very well on all frequencies which are multiples of 7.1 MHz, I feed it with coax cable terminated by a remote MFJ993 BRT antenna tuner and a 1:4 balun. I bypass the remote tuner on 15, 10 and 6m where the 1:4 balun is sufficient to match the Antenna. On 40 and 20 m and even 80m, the swr after tuning with the remote antenna tuner is perfect. On 160m, 60m, 30m, 17m and 12m, swr after tuning is between 2 and 3 and I use a second tuner in the shack to bring it down to less than 1.5. The loop is installed on the flat roof of my building at a height of 25m above the ground. I worked the whole world on FT8 on 60M and all above bands, a little bit harder on ssb but I am still happy of the performance, on 6m it is really spectacular when there is propagation, works decently on 80m but only for Europe no DX. On 160m it is warming the Sky, so no exotic DX FT8 stations are heard, in fact I hear almost nothing. Overall this is an excellent multiband Antenna, it could be also used too on 4m, 2m and even 70cm band as it resonates on these bands (but then only with a proper wideband 1:4 balun and it would also require to bypass completely - with transfer relays - the HF remote Antenna tuner).

[wildbill]

Nice video! I have been pondering putting up a 80m loop, I hear they’re quieter then open end antenna. Thanks for the modeling pattern of each band patterns very similiar to my 80m EFHW at 40ft.

[melvance]

Look into old antenna books. Been around for many decades. Fiirst antenna i used the early 90's. On 80...yeah. cloudburner. Above. The radiation angle comes down and is a very good antenna on higher bands