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Posted: 4/12/2024 2:07:17 AM EDT
Do you have a loop antenna? If not, why not? Is there a single person that’s had one and didn’t think it was the best wire antenna they could put up?
I have an 80m horizontal delta loop up at about 40’ at the corners. It’s coax fed with a balun. It’s better than at least half a dozen end fends I’ve had, way better than the DX-DD, better on 20m than a resonant dipole. Better than my DX Commander, better than an elevated 40m vertical I tried. I like it so much I’m going to put up a 40m vertical delta loop this summer. I’m even toying with the idea of an array of delta loops. If you can have a delta loop, you should have a delta loop. |
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Posted: 4/12/2024 8:34:22 AM EDT
[#1]
I have one if you can count a Chameleon Antennas Tactical Delta Loop (CHA TDL) portable antenna. It works pretty good for it's size and on the ground.
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TN, USA
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Posted: 4/12/2024 1:24:05 PM EDT
[#2]
Is it a triangle? Square? How close are the ends together? Is it fed from the end?
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Posted: 4/12/2024 1:58:53 PM EDT
[#3]
I know someone running a loop, 535 feet of wire up 40', fed with a 4:1. It covers 1.8-30 mHz SWR below 2:1 on all bands, mostly 1.5:1 or less except the upper end of 80M & 160M. One like it is next on my antenna project list.
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Posted: 4/12/2024 2:03:02 PM EDT
[#4]
Quote HistoryOriginally Posted By taliv: Is it a triangle? Square? How close are the ends together? Is it fed from the end? Delta = triangle. Mine is fed from a corner. Fairly equilateral triangle. |
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Posted: 4/12/2024 2:39:06 PM EDT
[#5]
Quote HistoryOriginally Posted By taliv: Is it a triangle? Square? How close are the ends together? Is it fed from the end? @taliv Any of those shapes will do; however, what's wanted is the most area inside the loop. In this case, the circle wins. One side of the loop is connected to each side of the feed line. (meaning, it's DC grounded) At it's fundamental frequency the loop fires broad side, perpendicular to the plane of the loop. If horizontal, that's straight up. On the higher frequencies the lobes begin to flatten out towards the horizon. I'd have one today except for the expense, I'd need a bucket truck to get the wire up high. They load very well on most HF bands when fed with ladder line. HTH 73, Rob |
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Posted: 4/12/2024 3:56:40 PM EDT
[#6]
Quote HistoryOriginally Posted By robmkivseries70: @taliv Any of those shapes will do; however, what's wanted is the most area inside the loop. In this case, the circle wins. One side of the loop is connected to each side of the feed line. (meaning, it's DC grounded) At it's fundamental frequency the loop fires broad side, perpendicular to the plane of the loop. If horizontal, that's straight up. On the higher frequencies the lobes begin to flatten out towards the horizon. I'd have one today except for the expense, I'd need a bucket truck to get the wire up high. They load very well on most HF bands when fed with ladder line. HTH 73, Rob I threw mine into tree limbs with an arborist throw bag and line. The only extra expense is 272’ of wire vs. 133’ for an end fed. |
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TN, USA
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Posted: 4/12/2024 6:09:42 PM EDT
[#7]
Ok so about my only chance for an 80m horizontal delta loop is going to be a triangle with legs that are 210’ 210’ and 90’.
Obviously very narrow and not much area compared to equilateral triangle much less a circle. Also I’d have a 40’ cabin in the center and it would be fed in the middle of one of the 210’ legs. Think that would work better than efhw or dipole? |
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Posted: 4/12/2024 9:20:41 PM EDT
[#8]
Quote HistoryOriginally Posted By taliv: Ok so about my only chance for an 80m horizontal delta loop is going to be a triangle with legs that are 210’ 210’ and 90’. Obviously very narrow and not much area compared to equilateral triangle much less a circle. Also I’d have a 40’ cabin in the center and it would be fed in the middle of one of the 210’ legs. Think that would work better than efhw or dipole? You are talking more about a 160m loop. My loop is 274' of wire total. Basically 91' x 3. I'd rather have a more correctly shaped 80m delta than a pie shaped 160m. If that's how far apart your trees are then I'd just use a lot of 3/16" or so Dacron and have your corner pulleys floating way out in the open. I use the clothes line pulleys from Home Depot. They're like 8 bucks and all plastic. My experience was that going from an EF/dipole to a horizontal 80m loop was about the same level of station improvement on both RX and TX as was going from 100w to 500w. |
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TN, USA
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Posted: 4/12/2024 10:03:18 PM EDT
[#9]
@robmkivseries70
When you say dc grounded does that mean I shouldn’t attempt to run the antenna through lightning arrestor / ground rod? |
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Posted: 4/12/2024 10:26:18 PM EDT
[Last Edit: robmkivseries70]
[#10]
Quote HistoryOriginally Posted By taliv: @robmkivseries70 When you say dc grounded does that mean I shouldn’t attempt to run the antenna through lightning arrestor / ground rod? @taliv Here is what I intended to convey, If you feed the loop with coax, the shield side of the cable will be connected to ground somewhere back along the coax path from the radio to the antenna. Thus one side of the loop is actually connect to ground at all times. (It works!) Feed with ladder line will involve a balun somewhere along the path, 1:1 is recommended BTW . The shield side of the balun fed with coax can be grounded at it's connection back to the tuner. In each case a tuner will be needed, and the chassis of the tuner should be grounded. With this ground connection it will be harder for charges to "build up" on a loop antenna. I still recommend disconnecting antennas in case of lightning. Way way back, I had a 40M delta loop (triangle, point down) fed at the top corner, mounted in the vertical plane. It did some wonderful things on 40M. I didn't keep it too long as I wanted 80M coverage as well. I later put up an 80M loop, it was mounted on an angle with one side only about 8 feet above the ground. Somehow, at barefoot power I QRMed a QSO in Europe. LOL hth 73, Rob ETA, I just saw your post about what would appear to be a isosceles triangle. Until some better supports can be put up I'd recommend a dipole or doublet. ETA2: I like tyrex13s solution. An 80M loop is 1005/ 3.5 mHz = 287.1429 feet around. It's not real critical, see what you can accomplish and experiment. |
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TN, USA
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Posted: 4/12/2024 10:51:02 PM EDT
[#11]
Thanks!
Ok good. I wanted to feed with co ax that goes through the ground doohickey so that’s perfect. However I really don’t want to use a tuner. Can this be tuned to be resonate? Can’t you just lengthen or shorten the wires? A 91’ equilateral triangle would be pretty easy. Was just trying to see if I could get 160m too. I’ll stick with 80m for now. How crazy would trying to hang a reflector under it be? |
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Posted: 4/12/2024 11:06:09 PM EDT
[#12]
Quote HistoryOriginally Posted By taliv: Thanks! Ok good. I wanted to feed with co ax that goes through the ground doohickey so that’s perfect. However I really don’t want to use a tuner. Can this be tuned to be resonate? Can’t you just lengthen or shorten the wires? A 91’ equilateral triangle would be pretty easy. Was just trying to see if I could get 160m too. I’ll stick with 80m for now. How crazy would trying to hang a reflector under it be? I'll disconnect my loop and post the SWR screen shots. I'm using the MyAntennas MyLoop balun. I'm listening to a local guy on 80m right now that has a tuned reflector laying on the ground underneath his horizontal loop and he has one of the best stations on 80m in the state. |
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Posted: 4/12/2024 11:23:47 PM EDT
[#13]
I could put one up, but it would cost a lot of money for the supports (towers), so that's why I don't have one.
I could do a 24' high version for under a thousand using telescoping flapoles for supports. But I am happy with my 6BTV and EFHW for now. |
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Posted: 4/13/2024 12:15:54 AM EDT
[Last Edit: tyrex13]
[#14]
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Posted: 4/13/2024 12:26:33 AM EDT
[#15]
Quote HistoryOriginally Posted By Jambalaya: I could put one up, but it would cost a lot of money for the supports (towers), so that's why I don't have one. I could do a 24' high version for under a thousand using telescoping flapoles for supports. But I am happy with my 6BTV and EFHW for now. What if I told you it will improve your S/N ratio on receive by 2-4 S units and your TX by 1 S unit most of the time? |
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Posted: 4/13/2024 1:49:59 AM EDT
[#16]
It's finally getting nice, so I will be putting together a couple of loops. The first will be a 20m vertical with the apex pointed down and terminated there with a 4:1 balun. It will be plumbing parts and cheap 7m fiberglass fishing poles. I have everything, just need to figure out how to make it all work.
Second will be a copy of the tactical delta loop. I am getting the stuff together for that one, it will be more challenging. |
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Posted: 4/13/2024 11:53:37 AM EDT
[#17]
@tyrex13 @taliv
The curves for the MyAntennas MyLoop balun look pretty good. IIRC, loops are pretty consistent SWR wise when going from band to band. I'd want a short run of coax of course, but this looks like a tuner in the rig would do the trick. I have to confess, I didn't know they made a loop balun. 73, Rob |
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Posted: 4/13/2024 12:01:19 PM EDT
[#18]
I use the tuner in the rig. 60m and 30m are above 5 SWR so I didn’t include them.
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TN, USA
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Posted: 4/13/2024 1:00:12 PM EDT
[#19]
I don’t have a tuner in rig. I have a qrp rig (and a couple more on the way) and qrp tuner and an amplifier. So can’t use tuner and amp at same time.
I just want it to be resonate on 80m and 40m and willing to spend some time to tune it. |
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Posted: 4/13/2024 1:53:05 PM EDT
[#20]
@taliv
How big is your amplifier? A used 100 watt tuner won't be very expensive. hth 73, Rob |
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TN, USA
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Posted: 4/13/2024 2:14:36 PM EDT
[#21]
https://www.dxengineering.com/parts/rmy-hla-305v?seid=dxese1&gclid=EAIaIQobChMIuLPUreW_hQMVOjfUAR1nugRKEAQYAyABEgLdxPD_BwE
Not exactly sure but it says 250w max output on the advertisement but the manual gets a lot closer to 300w for 40m |
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TN, USA
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Posted: 4/13/2024 2:29:24 PM EDT
[#22]
Ok so if I get something like a 2” pvc pipe to connect the ends of the loop and provide strain relief from the electrical connection, how long should the pipe be?
Say I run heavy coax up from the ground rod and then split the shield from core and connect core to one end of wire and shield to other end of the wire held together by the pvc pipe. And this is roughly center of one leg of a pretty close to 91’ equilateral triangle. And hoist the whole thing prob 34-40’ in the air with some droop where the coax hangs. How long should the pvc pipe be that separates the ends? Or does it not matter since they come together in the coax? Would a balun help if I’m not using a tuner? |
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Posted: 4/13/2024 2:48:53 PM EDT
[#23]
Quote HistoryOriginally Posted By taliv: Ok so if I get something like a 2” pvc pipe to connect the ends of the loop and provide strain relief from the electrical connection, how long should the pipe be? Say I run heavy coax up from the ground rod and then split the shield from core and connect core to one end of wire and shield to other end of the wire held together by the pvc pipe. And this is roughly center of one leg of a pretty close to 91’ equilateral triangle. And hoist the whole thing prob 34-40’ in the air with some droop where the coax hangs. How long should the pvc pipe be that separates the ends? Or does it not matter since they come together in the coax? Would a balun help if I’m not using a tuner? A current balun will always help reduce common mode current when feeding a balanced antenna with an unbalanced feed line ( coax ) I don't think it matters how long the PVC pipe is. All you need is strain relief. In fact I think the shorter it is the better otherwise because the longer the PVC pipe is the further apart the wires are and the longer the connection wires coming out of the coax and that spacing of the coax wire to the loop wires and the length of that connection is going to introduce capacitance in the antenna which may or may not require added inductance in the tuner to match it based on freq and length of the loop. |
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Posted: 4/13/2024 2:51:19 PM EDT
[Last Edit: robmkivseries70]
[#24]
OK, thanks for the info, I expected a 100w amplifier. LOL First a technical notion, are you OK running the amplifier at 200W or less? To gain 1/2 an "S" unit over 200W you'd have to run 400W. i.e. There isn't much difference between 200W and 300W.
The My Antennas Loop box by itself might be made to work on the two bands with out a tuner but I'd sure call and talk to them about what you want to do. To some extent, any antenna install and how it reacts (tunes) is location specific due to ground conductivity , height above ground etc. There are some used MFJ 969 tuners, at dealers. I used an MFJ 969 until I got into running bigger tuners, just for the efficiency. The nature of the loop makes it easy to tune as the impedance doesn't change a lot from band to band. There is a way of matching a coax fed loop by inserting a length of 75 Ohm coax in the feed line, I don't know how well this matching carries over from band to band. I'd sure consider a tuner for the next piece of shack equipment. For now, you might fall back to a fan dipole for 40M and 80M and tune each antenna for your favorite frequency. At power, you'll want to monitor the antenna system for the sake of the amplifier. hth 73, Rob ETA: I just saw Mach's comment. I like the idea of the delta loop, that's good height too. The only thing I'd add is to be sure to tape/ seal the coax so it doesn't get any water inside. There used to be a picture in the hand book of wrapping the coax over the top of a feed point insulator to prevent water from being pulled down the inside of the coax by gravity. As Mach said, solder, tape and strain relieve the connection. |
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Posted: 4/13/2024 9:34:55 PM EDT
[#25]
Quote HistoryOriginally Posted By tyrex13: What if I told you it will improve your S/N ratio on receive by 2-4 S units and your TX by 1 S unit most of the time? That's compelling. I usually have a good low noise floor 20m and up. I'm in a very small rural town so not a whole lot of noise, even with a power plant only a mile away. 40m is always noisy but I guess a lot of it is just naturally occurring. |
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Posted: 4/13/2024 10:04:14 PM EDT
[#26]
Quote HistoryOriginally Posted By Jambalaya: That's compelling. I usually have a good low noise floor 20m and up. I'm in a very small rural town so not a whole lot of noise, even with a power plant only a mile away. 40m is always noisy but I guess a lot of it is just naturally occurring. If you have the real estate I can't recommend it enough. the 80m delta loop is a banger on 40m. Really al the bands. |
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Posted: 4/13/2024 10:09:03 PM EDT
[#27]
Quote HistoryOriginally Posted By tyrex13: If you have the real estate I can't recommend it enough. the 80m delta loop is a banger on 40m. Really al the bands. I have one on my list to do. I was also thinking of doing a 160m loop but its low on my list. I made an 80m vertical wire one time, and it was cool but did not do much better than my Doublet. in fact is had a lot of noise. |
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Posted: 4/14/2024 12:02:27 AM EDT
[#28]
Quote HistoryOriginally Posted By stanprophet09: I have one on my list to do. I was also thinking of doing a 160m loop but its low on my list. I made an 80m vertical wire one time, and it was cool but did not do much better than my Doublet. in fact is had a lot of noise. Long Doublets can perform really well, but I've never had one up. There is one guy here with a long and high doublet and he's really the only guy that sounds as strong as some of the other big 80m stations in AK. |
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Posted: 4/14/2024 4:29:36 PM EDT
[#29]
I am just tuning the wire away from having 20m "portable" delta loop. I got all the plumbing fittings glued, and have everything fitted including the wire. It's just a bit windy to try and get it tuned.
I have the wire running inside the fiberglass poles and pvc. It's kind of a bitch to do this way, but looks very clean. I will try to put up some pics. I threw a meter on real quick and having cut the wire long, it shows 2.03:1 at 13.885Mhz. That is encouraging, and I think it will tune up where I want. |
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Posted: 4/14/2024 6:35:13 PM EDT
[#30]
According to my reading. The small vertical delta loops essentially have the same transmit efficiency as a 1/4wl vertical with 32 ground mounted radials and better RX signal to noise.
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Posted: 4/14/2024 8:07:58 PM EDT
[#31]
 Attached File Attached File Attached FileIt tuned about 1.4:1 across the whole band, really flat. I got a true 59 from the maritime net, and two 59 from a a couple of pota contacts. The guy who checked in to the net after me was in TX, and he commented that I was 59 to him as well. I need to figure out wire terminals that will fit through the fishing poles. Overall I am pleased with the build, and just have to finish the details. |
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Posted: 4/14/2024 8:41:29 PM EDT
[#32]
Quote HistoryOriginally Posted By lorazepam: https://www.ar15.com/media/mediaFiles/242375/IMG_20240414_173454959_jpg-3188106.JPG https://www.ar15.com/media/mediaFiles/242375/IMG_20240414_160427151_jpg-3188108.JPGhttps://www.ar15.com/media/mediaFiles/242375/IMG_20240414_161819247_jpg-3188110.JPG It tuned about 1.4:1 across the whole band, really flat. I got a true 59 from the maritime net, and two 59 from a a couple of pota contacts. The guy who checked in to the net after me was in TX, and he commented that I was 59 to him as well. I need to figure out wire terminals that will fit through the fishing poles. Overall I am pleased with the build, and just have to finish the details. Niiiice |
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Posted: 4/14/2024 9:15:12 PM EDT
[#33]
I cut a lot of wire off, and I think I can cut off 6" on each PVC pipe holding the fishing poles. They aren't glued, I wanted to make it somewhat portable. The wires are inside the fiberglass poles and PVC.
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Posted: 4/25/2024 2:19:37 AM EDT
[#34]
I am liking the delta loop. Resonant on 20m, and I can tune it for 17, 15, and 10m. 20 was nuts today, there was zero empty space. I don't think it is directional, I made contacts in TX, MA, NM, SC, BC Canada, Ontario, and Spain. It will be set up for the hootenanny.
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Posted: 4/25/2024 10:31:24 PM EDT
[Last Edit: lorazepam]
[#35]
Another update. This is a great antenna. I tried it on 40, 20, 17, 15, and 10m and had no issues at all. I ran it with the amplifier on ft8 and made contacts on every band tried. I got NZ, AU, JA, spain, albania, canada, several US, cuba, brazil, GB. I want to see how it does with a mast, and getting the apex more than 6' off the ground. I need to figure out how I can make it durable enough to use at home.
Edit:  Attached File |
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Posted: 4/26/2024 1:43:15 AM EDT
[#36]
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Posted: 4/26/2024 12:19:47 PM EDT
[#37]
I’m surprised it will tune 80m! Snow is almost gone, hopefully get my 40m vertical loop up soon.
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Posted: 4/27/2024 4:33:23 PM EDT
[#38]
Quote HistoryOriginally Posted By tyrex13: I’m surprised it will tune 80m! Snow is almost gone, hopefully get my 40m vertical loop up soon. Xiegu tuners rock. There may be other things not quite so top drawer, but their tuners are as good as anyone makes. It's around 9:1 prior to tuning. |
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