Minimum height for a full wave loop

[KJ6AJL]

I'm thinking about taking on the challenge of putting up a full wave loop for 160M and I'm curious what the minimum height should be. Is it worth the time and money to put one up if I can only get it 20-30 feet off the ground? I know I won't work much DX on 160 at that height, but it will be feed with ladder line, so I will be using it on other bands as well. Also, this loop would encircle my other antennas and I need to know how they will interact. How far away from the loop do they need to be? I'd like to be able to share supports to keep the cost down.

Thanks.

[WB2WIK]

That's so low the wire sag will make it a lot lower in between supports...may not be worth the effort.

However where there's a will...

I work Don KG9OM quite often. He uses loops about 50' above ground as shown here: http://www.k4qky.com/antennas/multi-band-loop.html

...and they work well for him. But those are at 50' above ground. I know Don experimented a lot with this, back at his old QTH in KY and also at his current one. His discussion on the website link provided above provides some insight about what he found.

[W5DXP]

I'm thinking about taking on the challenge of putting up a full wave loop for 160M and I'm curious what the minimum height should be.

A full-wave loop radiates broadside to the loop. If the loop is horizontal, most of the radiation will be almost straight up. At any reasonable height on 160m, that makes it an NVIS antenna. Or are you talking about a vertical loop?

[KB4QAA]

Worthwhile? Compared to what?
,
What are your objectives? If you are happy working regionally this would be good. If you want to work Europe from California, then you need it a lot higher.

Nobody can accurately answer all your questions. Put the antenna up. Do what you can. You won't learn anything if you don't try it!

[N0AZZ]

I will tell you how mine worked it had varying heights using existing supports @ 50/40/25/18' and a very ragged rectangle. Ladder Line is a PITA to use and not necessary at all. I used coax all the way and it was fed from a corner at my tower close to the house to a tuner it worked from 6-160m. It was the best antenna that I have used and I have a lot of antennas for North and Central America on the low bands 30-160m. In fact in the first 160m SSB Contest I worked 43 states and 19 enties under poor conditions it was excellent on 80/160m.

I had yagis and beams for all bands 432-40m and verticals for 440-160m as well and dipoles covering the same so I did a few to compare to. It is known as a quiet antenna the jury is out here on that, granted it's not a great DX antenna but did work a little a few times mostly EU's. If you want a good low band antenna for NA,CA it's well worth putting up and 30' will surprise you I think all you need is wire and a balun, coax.

[KJ6AJL]

Thanks for the info, I'll check out that web site. My goal is to experiment and have fun. I'd like to have something that can work DX on 80M though. My understanding was that a loop cut for 160 would beam the majority of the energy straight up, but on 80M it would radiate at a much lower angle. Is that accurate?

[WB2WIK]

Thanks for the info, I'll check out that web site. My goal is to experiment and have fun. I'd like to have something that can work DX on 80M though. My understanding was that a loop cut for 160 would beam the majority of the energy straight up, but on 80M it would radiate at a much lower angle. Is that accurate?

Not at 20-30 feet, it won't. Still, even if it has substantially less than 0 dBd gain at lower angles, you'll make contacts!

I've worked VKs on 80m from my van using a 7' tall mobile whip; it's all in "timing" and being there.

As Don Wallace W6AM told me 35 years ago when I asked him his secret for working so much DX: "Be there when the DX is."

[VE3FMC]

I'm thinking about taking on the challenge of putting up a full wave loop for 160M and I'm curious what the minimum height should be. Is it worth the time and money to put one up if I can only get it 20-30 feet off the ground? I know I won't work much DX on 160 at that height, but it will be feed with ladder line, so I will be using it on other bands as well. Also, this loop would encircle my other antennas and I need to know how they will interact. How far away from the loop do they need to be? I'd like to be able to share supports to keep the cost down.

Thanks.

When I upgraded to HF privileges in 1994 I put up a full wave horizontal loop for 80 M, coax fed. Feed point was right above my shack at 29 feet. Then the loop sloped down to about 15 feet at one corner, 15 feet at another corner. Came up to about 20 feet to a support on the other end of the house. Over to some trees, so it was only about 10-12 feet off the ground there. Then back to the tower at the feed point.

I managed to get WAS with 100 watts on 75 M phone with that antenna. Also worked some DX. Mind you my signal wasn't strong to the DX stations but I managed to work them. However I had a killer signal within a 300 mile radius. One guy in Ohio near Dayton always thought I was running big power here because I was always 30-40 over when I talked to him.

Not sure what your results would be like on 160 but I had fun with that low loop I had up. Didn't know how crappy or how well it worked because I had nothing to compare it too