The Mega-Loop: Exploring the Fascinating World of Large Triangle Loop Antennas
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- Опубліковано 4 сер 2022
- Incredible characteristics on this one. Particularly on 20m and up. But still outstanding on 80m and 40m too. If you have the space, please build one! Callum, M0MCX.
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My first antenna was a 40 meter delta loop at ~45 feet using a balanced line and an external tuner. I was able to work 100 countries on just 10 meters. It also did well on 20 meters but started getting a tad NVIS on 40 meters. If I presently had the facility I'd have another one. I also used old window weights attached to a separate paracord running across a nautical pulley to act as a stress relief in windy weather.
I just wanted to thank you sir. With the inspiration from this video I decided to build a 10 meter delta loop. I am only a technician so 28.3 to 28.5 is all the access I have to HF. On Christmas eve at 10am I made my first HF contact from the state of Georgia in the US to KD70BAD in Germany (4651 miles). Thank you for everything you do us.
Moe KO4GBB
Top banana!
Thank you nice antenna Callum
You are welcome!
When I lived in Upstate NY (Clifton Park) I had a fullwave loop for 160. It was a flat top for 160, up about 70 feet. I fed it with 450 ohm ladderline. I used it for many years until we had a Hurricane come up the coast and thrashed it. I loved it. I could run any band and hear everything. By the time DX called i had already pounced on them before everybody could swing their beams. It waa so sensitive and quiet you could hear a mouse fart in Mongolia.
Im on a small city lot now and run a vertical. I can pretty much hit anywhere except India. Its driving me crazy. Thinking about a half-square. Wondering if I can get 40/30/20 from it
Mongolia have mice? OK!
Hi Calum, I have used this 160m mega loop for 24 yrs with open wire feeder, only way to go. Wayne VK2DWP Wagga Wagga
Fabulous!
Always something fun. Thank you.
Glad you enjoyed it!
Thanks again Calum.....Excellent info. I need to get off my butt and get building mine. 👍
Do it :)
I am so jealous of all the wide open space you have to experiment!
Many thanks for another interesting and informative video, Cal!
73 from America (but not the wide-open part)
Not the wide open part! Yes OK! :)
Love my 80m loop. Not quite a triangle, has 5 corners. Works great!
That'll do!
love it!
Wished I've seen this way back when I put up my Full Wave Delta loop up, 10 thru 80, 270 ft (82m) but also tunes on 160 (4.5 swr )on 160, tunable!!! Just drew it on paper and a bunch of math, I went with some homemade ladder line instead of coax, #14 solid conductor, because it was just laying around, spaced out to 1.5 inches at around 460 ohms of impedance. Wired to a 9:1 unun, flat swr all across the spectrum. Only place I use a tuner is on 160 , swr is 4.5, I think I said that already, 👍 I wonder what 100 watts looks like for me, at least 1kw, maybe??? Awesome loop, and thanks for the info!!! I have to download that program for my future builds!!! 👍 73's N3WUB
Have fun!
Love to see a 160m square loop. One of these days I will live somewhere with big trees and would love to put one up.
Square. Copied. In the video log. Hang on.
Great video Cal! Never tried a triangle mounted horizontally like that, although I had a good results with the regular delta loop
Yes OK Rafael!
Cal, you da man! Last year You did a video on delta loops that really got my attention, and this just reinforces my enthusiasm. I'm still on an 80M EFHW and it's, I think, an underappreciated antenna, but I've been able to tune it from 160- 6 M. That being said I have an 80M FW Delta loop I've not been able to hang (hurricane, procrastination, need tree work) but I have renewed determination to get it done, then start planning my Mega Loop! Keep them coming, my friend! I still hope to have a QSO with you sometime. Tim KG6G, formerly K3LSU
Procrastination rules!
Callum, some years ago this Brit chap was on UA-cam talking about the Meg-O-Loop (yes, "OH"; that's what it sounded like coming from his / your lips). Anyway... sporting a mohawk haircut, I believe, it was of great interest to me as I have 100 ft tall doug fir trees surrounding my house. So I constructed an air cannon and shot lines over the very highest branches. All evidence says that this was the Spring of 2013. Made with stranded and insulated #12 electrical house wire, one leg at the North end is about 60 feet long with the other two just over 100 feet, forming an 80m loop fed at the South apex just above my home office/shack. I found a VGE HiQ 4:1 balun, stashed away from my youth (1980's vintage), and about 100 ft of LMR-400 coax to feed it with as the elevation of said loop is about 90 feet above the ground (!bonus!). And I live literally a stones through above the salt waters of Puget Sound (25 feet above sea level?) so that can't hurt, eh.
This was a "temporary" antenna... only it turned out to be permanent and it's still really my only permanent antenna installation at home still. A couple years ago I paid an arborist to install stainless pulleys in the trees and free up the lines that had cut in to the limbs causing the tree to heal over them. Periodically I get tempted to put up a hex beam on the 32 ft tower that sits in pieces behind my garage but usually think "WHY"?? The Meg-O-Loop is working gangbustahs.
Performance is spectacular. If I can hear them then I can work them, and it hears a LOT. It's quiet on receive and I can have as many Chinese wall wart switching power supplies in the house, below, with no detection of noise at all from them. Not true though when I did what others kept telling me and got rid of the balun and coax for balanced line and a tuner instead. I believe that the vertical section of balanced feed picks up stuff from inside the house and I have to turn off certain lights and such in that case. I wound a new balun on a pair of FT240-43 cores which will be an upgrade from the aged balun that has been of service for so long.
I work DX on 20m, 17m, 15m, 10m and the 40m nets and stations in the Western part of the USA with ease running 100W. The only "wish" is that on the full wave resonant 80m band the impedance wasn't asking for a 2:1 transformation. I end up using the rig's tuner which is of course tuning up the coax. It works but I'm sure it's inefficient and who knows what the radiation pattern is as well as radiation in the shack. My hope is to add a relay to the new balun that can tap it such that when energized it will be a 2:1 transformer. Perhaps using a d.c. blocking capacitor so I can energize it by pushing d.c. up the coax when I am on 80m.
The loop has been tried by me on 6m here but only briefly one day to satisfy curiosity. I wonder if your thoughts on 2m and 70cm might neglect to consider the core material suitability up at those higher frequencies? It would be interesting to make a balun just for up there that could be switched in to see, perhaps during a VHF DX contest?
Long story, I'd like to thank you for reading my mind and revisiting this antenna. The other day I went looking for the original video that you had posted and I had shared with fellow hams over the years but I could not find it. So I was thinking hard about contacting you to learn what happened to the mohawk / Meg-O-Loop video (archived or ???). We all know about the success of your UA-cam channel as we enjoy the content so please keep it up (yes, "Subscribed", long ago)!
Wishing you all the best. Cheers.
I'm sure the 80m mis-match would have been fine.
Thanks for yhe video. I use a efhw for all dx, but wanted to build a flat delta for close in stuff!
I have an 80m full wave skyloop (roughly 275ft long) fed direct with rg6 75 ohm cable (yes, 75 ohm), no balun, set up in an uneven triangle. One corner is roughly 60ft up, one corner 35, one corner 25. It is a pileup buster. I don't have an amp, just 100w barefoot and I don't run an external tuner, my ft450 tunes it fine with very few exceptions. I absolutely love this antenna. I hope to raise the lower corners soon and expand it for 160m. Btw, keep the videos coming, learning a lot from them. Hope to hear u on the band's, stay safe! 73. N2SCD
Ah. There you go. Nothing wrong with 75 ohm coax.
@DXCommanderHQ what wire type did you end up using kind sir , and any advice rigging it in the tree with out climbing a 90 ft pine tree. I have an arborist sling shot in my E cart, haven't worked out how the tie off the line to the antenna ring.
THANKS Again !
I used jacketed wire (12awg i think) I found in the electrical section of one of the big box stores. It may be southwire but I'm not sure. Bought a 500ft spool of it.
As for getting it up in the tree, the best way I have found was with a sling shot/wrist rocket, a lead weight and a cheap open reel fishing pole. If you have a drone, you wouldn't need the slingshot/wrist rocket. I hold the fishing pole with my feet (tip of the pole pointed in the general idea the weight and string will go), put the weight with the string tied to it in the pouch of the slingshot and send it. Experiment with the weight size, I can't remember how heavy a weight works best for me but I think I started with a 1/2oz.) since the fishing line will produce drag through the air, one to light won't go as far as a heavier one. To heavy and the weight is hindered by gravity. I got the stuff at Walmart and the daisy slingshots seem to work really well. The pole was a short uglystick with an open reel in the pack (the cheapest pole they had) and the lead sinkers were in a round pack with several sizes. Until you find the sweet spot of the sinker size, it will probably take several tries to get the fishing line up there. Once the line drops, I cut the weight off, tie Paracord to the fishing line, electrical tape the knot and reel the line back in. Easy as pie. One more thing, I can't remember what size fishing line I use, but that can make the difference to the weight breaking from the line when shot from the sling shot. That's a lot of force put on the line by the weight being launched. I have done several antennas for myself and a neighbor's this way. Good luck!
@psychodadsn well I have a couple 1000ft spools of that in the shed 😄 I have the arorborists sling shot in my amazon Cart the use them to shoot throw lines in trees. Figure I would tie the first branch with a paranoid and slip knot, then float the rest because the 80+ foot trees move in mountain storms a lot. Making sure to have 8 or 10 feet of shock cord at the other end. Not sure how much sag that will create. I plan on feeding it with a 4:1 like the video did and using LMR400 to get as many of my 10w into the wire as I can. Did you start with 160m of wire and tune it a bit . I'm using a little LDG tuner not sure how big of a mis match she will clean up.
Thanks for your help.
You may not get much sag. Mine is an odd shaped triangle and I don't get much sag. I used a black bungee cord at one end for when the wind blows the trees. I started with about 270ft of wire (80m skyloop) because I didn't think I could fit in a 160m skyloop. I later added roughly 5 feet to bring in the swr a bit. I first used a yaesu ft450 with a built in tuner, then upgraded to a ftdx10. I don't use a balun. My jumpers to my tube amp, power meter and switches (1 for an antenna switch, another to a Kenwood ts511s tube transceiver) are 50 ohm premade jumpers, the main feed line to the loop is southwire rg6 with proper compression fittings made up with proper prep tools. My ftdx10 internal tuner can tune 80-6, as could the ft450, without issue. If I wanted to, I could probably fine tune the loop more, but it seems to work fine so I'm going to leave it be. I can bust through many pile ups within the first couple tries. I absolutely love it. I'm mostly on SSB on those bands, but will sometimes do js8, mostly on 20m. I find 80m to be more nvis while it's really good for dx on 20 to 10, 40 doesn't seem as good as 20, but is still really good. I haven't caught a good opening on 6 yet to try it there. I've tried other end feds, a nested Marconi and a monoband raised vertical. The loop blows the others away, except the raised vertical which comes close and occasionally is slightly better for certain dx stations.
Great antenna video de W2CSI
Thank you!
I've been toying with the idea of a loop where one corner is near the peak of my roof so that two sides slope down to opposite corners of my fence (~1.5m above the ground) and the feed point is in the middle of the side where the corners join. I guess I need to see how that looks in the software! Thanks Callum!
OK, I remember modelling that years ago for a field-day. Still works, not quite as agressive on the lobes.
Very cool! Will you have a video of you putting up this antenna? I would thoroughly enjoy that video. Thanks for sharing Callum!
I am thinking sometime in September..
Love to see the comparison between coax feeding and balance feeding these loop does for power ? Great vid Cal we always preached about full wave loops and doublets on our freq esp when we can pass on the knowledge, it’s kinda needed when on low band. compromised antenna on low band in summer static can be very hard on the ears ☺️
Me too Cal
Balanced or coax, apart from some tiny losses on the coax (and possibly some small losses in the outboard tuner for balanced) I would say basically the same BUT balanced line would mean that dimensions are not critical at all.
I run a similar triangular loop, about 270m all round and use balanced 150mm open line from a Palstar BT1500A feeding half way on one leg.
Balanced line almost lossless and VSWR on the line than is largely immaterial.
It works. . . . . . . . . . . .
Hi Cal. I have had a 160 m loop up for some time and have changed it to a 6 sided and feed it on the southern side. Now I have some big lobes coming of the side and the front and more as i go up in Freq. Not using my Verticals for 40-20m any more just the loop. 400 watts helps. Getting sometime better reports on TX than RX. Hope to catch you one weekend on your DX the propregation drops out once it gets dark here but getting better as it warms up. Cheers VK3DJC
Very interesting David..!
Nice video. I wonder if I should just try a square loop around my property - fence. The only difficult bit would be the drive way - so would have to be high. I am sure the neighbours would hate me ! That is why the DXC is so good !
Really enjoy your videos. You put things in real world terms with real world examples and explore factors that real hans consider! 73s DE ND4A
Tnx Tim!
you have that huge field behind your warehouse and I’m talking outside the fenced in area… that would make a great ground loop! you can be outstanding in your field
Haha yeah.. I know the guys here. I could easily grab more land. I would need to pay for the fencing though!
Loops are great. Whether triangle or square or round - simple cheap robust and they work even squashed into a small garden! 73 Ed.
Indeed. Once hooked, you can't get off them!
I try this a long time ago on 27.550 But not a big deel. Vertical is a vertical no mather what. In my case for sure. Love you Call😉👍🥂Happy new year
Not this one! ua-cam.com/video/V8Qq4-0_TjQ/v-deo.html
You know if you sold a megaloop kit, precut to the best dimensions, maybe different sizes, I'd buy it. And I don't see anyone else selling them.
Pre-cut.. The problem with pre-cut is that if coax fed, the tune will change by a small amount depending on height.
Hey Cal, one little note you over looked. GAIN works in both directions so if you have +9dBi on TX you have it as well on RX so your 100w becomes 3200watts EIRP but not only that your contact on the moon's 100w beams in like they are doing the same for the same power....less front end gain lowers the noise floor....people forget the simple stuff. Passive gain works way better than active gain as passive is generally less noisy. Great video. Been catching up whilst working in Vanuatu beats the local TV. Cheers.
Indeed! I have so much stuff in my head that if I regurgitated it all - I would fill up UA-cam! :)
@@DXCommanderHQ oh go on. I am sure all of us would watch it...the thirst for knowledge is great for everyone on here i am sure. Keep up the great work.
Triangle delta loop designed by SP7LA (SK) as great performance, with original dimensions works on 80-6m bands without ATU. Those are great antennas, but requires lots of space (huge gardens)
Cool, thanks
@@DXCommanderHQ triangle się dimensions are 23.87 - 35.10 - 23.87m, balun 1:4, high of triangle should be 16.18m. and as I remember this antenna is not working only on 30m band (at least without atu). Link to desing picture obrazki.elektroda.pl/7937942000_1514824008.jpg
Hey Callum.......you know I have a v-quad that I use on 11 meters and I love it.......So my love affair with triangles is well founded......they do have some unque characteristics.......
In theory, a circular loop will give the best performance because it encloses the biggest area. Next would be a hexagon, pentagon, square then triangle. dB gain wise the difference is small, but it shows that any shape will still perform well. I used, not quite, horizontal loops for sevaral years culminating in a 160 metre triangle fed with 450 Ohm balanced line. In combination with a vertical to fill in the nulls, it was a very effective multiband antenna.
Well, there is no more gain. We can make any more energy. It MIGHT be more omnidirectional, but then we would lose the lobes and the nulls. Good thinking though. Remember, dipole is about the best you can get in two directions.
GI0UTE, des here. I run a triangle loop, not quite equal sided, but 240m long, 15m ish high. I feed it with window line and a balanced tuner on all bands, 160 to 6m. What you didn't mention Cal is how quiet loops are. My loop has a 10 lower noise floor on 20m, 5db on 40m compared to dipole type antennas in the same location at the same height. It allows you to hear weak signals very well. On 2 out of 3 QSO's it's better on my loop Vs my 80m off center fed dipole, must be the lobes and nulls. Mine too has a big lobe into south America. Works really well there on 20m. On 80 and 160m it's great for NVIS/ local stuff. When qro on 80m it can crack most all local pileups. I like it.
I tried it with a 4:1 balun and it wasn't quite as good, not as quiet was the biggest difference. Just my experience.
Cheers des.
Yes, loops are quiet!
What do you think would happen if you put a relay at each corner so you could move the feed point around to reorient the nulls when needed? Would the closed relays at the unfed corners cause too much of a reflection?
Haha.. You are as bad as me.. I think up stuff like this too.. Yeah, go with it :)
Very interesting video, I think I have the room to make a Mega Loop antenna, it may not be a perfect Triangle but I might use Electric Fence wire (so I can keep it stealthy from the HOA police) and see what that does. If you haven't already done it can you do a video on how to use MMNA (for us dummies) so we can learn how to predict what our antennas look like.
OK Mike, surf through some of the playlists. The MMANA tutorials are in there.
Nice video thank you, please do the square loop with same assessment :)
Yes I will do..
@@DXCommanderHQ Thanks again Calum for doing this video. I've been trying to duplicate your results and can't get the nice pancake elevation plots you are getting. My results are less inspiring with higher elevations. I must be doing something stupid... 53 meter leg triangle up 50 feet. Any chance you can share a spreadsheet file for your examples in this video? I'm using CocoaNEC 2.0 for the Mac to model these.
Loved this! Understandably, there are lots of videos for small plot antennas, so it's good to see what can be done if you have the space.
Do the sides of the triangle or rectangular loop have to be equal? I'm fortunate to have a long plot but it's narrow, about 400ft x 40ft to play with and my neighbour says I can use his 50ft poplar tree along with my own 30-40ft trees.
This might be a too involved question here but perhaps you could bear it in mind when you do a video on loops. Best 73,.
OK, so as you change the shape, the lobes start wandering off.. But that's OK, you will still have a lot of fun.
@@DXCommanderHQ Thanks Cal, that's what I thought/hoped you would say. The moral of the story is not to get too bogged down with what the ideal theory is give it a go! I might need some DX10 or similar in the Autumn!
More more more ... I need to know the starting point of this sorcery 😉
We have a remote cabin in the remote Serria moutain range surrounded by 100ft trees @ 6700ft elevation, this sounds perfect for my little IC705 😍😍
OK, get one up my friend - and enjoy it! Use heavy 16mm shock-cord between the trees.
I'm new to Ham radio. I've got limited space in my garden 9.4m x 5.7m. I was thinking of building a Delta loop for CB. I've got an Icom AT-130 tunner. Any thoughts on how or where to attach it?
HUGE topic and why you want a delta loop.. Anyway 9.4 x 5.7 is bigger than my original development area. If it's CB you are after, jst buy a CB antenna.. If it's ham radio (like more than one band) then honestly, you need to start with something REALLY easy. SUggest 20m dipole on a wodden pole maybe. Your Icom tuner WILL tune anything but you will learn nothing :)
Hi Callum, I tried to design a Delta Loop for 160 in MMANA with a feedpoint in 1 corner and it shows 13 Ohms impedance instead of the expected 200 ohms. The plan was to hang that up for the next Field day. But that would not allow the 4:1 ballun approach. any Ideas what I did wrong ??
Martin
DK3UW
Martin, known bug in the raw mathematics for models under about 1/4 wavelength above ground means you can show lower than expected impedance. Don't worry about it. It'll work just fine.
just saw your reply in my Spam folder. I will relocate my station in spring into a garden hut and may be allowed to include the neighbors trees so just might squeze a 160 m loop around the property. I will report if that works.
My horizontal loop is at about 80 ft. 530 ft long and it performs as well or better than my 3 element yagi at 40ft. But my 40m delta loop @ 75ft receives better than my 160m loop on 40m 2 to 3 db sometimes. It doesn't make sense sometimes.
Making sense.... Yes!
The lowest dips on the plots are still going out a long way, the plot isn't round so by location signals may not be equal, but it's not like there is no signal there.
I don’t have the room for a 160m loop, but have 3 trees for a perfect triangle 80m loop at 30ft. I shall give it a try for 20-10m bands.
PERFECT!
I run a version of the megaloop or skyloop, and I'm very very happy with it. Is it the best antenna? Absolutely NOT. It is the best for me (yes), but it may not be the best for you, so on and so fourth. Do research to find what antenna's will work best for the room you have to work with. However, never stop experimenting! 1/2 the fun is to never leave good enough alone, hence getting yourself into trouble figuring out what you screwed up this time because you just couldn't leave things alone....... Sorry, my ham radio story :) but it is fun and love it.
I agree. Half the fun is building stuff and working out if it works!
what a magnificent lightning protection array...........LOL
Hope the Scouts are getting the Communication badges
Haha. They all did!
Do the square Cal, current best for me is around 19,000km to the Azores @ 40m on 10W.
Square coming!
what modeling sw is used in the vid?
I use MMANA. Free. I did some vids on it. check playlists or search "dx commander mmana".
cheers calum have youever worked david evy from the west midlands on his mobile crane mounted 90m homebrew yagi?@@DXCommanderHQ
Is a delta antenna quiet?
Loops CAN be quiet unless you have genuine real noise locally - then they WILL pick it up. I've proved that with my local 90m loop out the back. Same as the vertical..
So -- in general for shortwave dx you should aim at 3 to 8 degrees above horizontal.
In the main yes. For AM / Shortwave in medium-wave bands though, it could easily be higher sometimes. Up to about 15 degrees.
@@DXCommanderHQ Does the higher angle correspond to a shorter distance?
What, if any, are the RF hazards of bringing ladder line inside the shack to go to a tuner, then your rig? Any RF danger to humans at, say, 200 watts? Any negative effects on equipment? Any solutions? I've not seen this adequately addressed, only casually mentioned. Thanks. mike -- KM5MD
None.. Balanced line won't radiate.
@@DXCommanderHQ Thanks. I'm wondering, and maybe I'm a bit dense, if it doesn't radiate, how does it radiate a signal outside of the shack for transmission?
@@mrcoog3k832 it doesn’t radiate. It’s a balanced feed line. It will only radiate if it becomes unbalanced. The antenna at the end is what does the radiating.
why a triangle may be the optimal shape my kidney shape loop work fantastically! I want to get several thousand feet of wire and make a gigantic colossal loop
Does your research licence restrict you to verticals only? Just wondering.... 😉
Nope. Anything I fancy.
Callum, what is ur QTH now?
Holly Farm Business Park :)
I would have loved to turn down my power to 0% on my rig, operated this antenna. those mW leaking out of the finals would like 40W with all that gain...
Haha yes!
wonderful video would it tune to 11 meters if it did i could use it at moms, she has already said no to the pdl2 i showed her what i was going to put up in her garden without even thinking about she said no lol.
dave
Says no to PDL2 LOL! HAHA :)
yes she did i nearly cried lol so looking for any suggestion's please help me
dave
Hi Callum.. I'm a Huge fan of big horiz loops.. started with a 568' Loop.. years ago.. Wow. It's good to know I could get by with only 3 supports instead of maximizing the area as was the original theory. Finally got a QTH with some space and trees.. Going for a 3 or 4 wavelength on 3.5M with open wire and nice balanced tuner, up about 60 ft. Should tune fairly nicely..
Ever do a transmitting magnetic Loop antenna? Very sharp tuning with a H.V. variable capacitor..
Callum.. one more thing for the big loop.. do low angle DX patterns have any favor of Even or ODD harmonics of the loop wire? say everything optimized for 7.025 CW Would a say a 7 wavelength Loop have a better/worse low angle DX pattern than a 8 wavelength loop?
Now.. Mike M0MSN (check his channel out) loves his magnetic loops..
OK, so larger loops. I can't say for sure but on the modeling, it gets worse over Mega Loop size.
Who climbed those trees?
Don’t need to climb I built a air cannon out of 6” pvc x24” long with end caps and a tire valve with a 2.5”spa valve to a 2.5”x24” long barrel I launch a throw weight (16oz)tied to throw line over the tree then pull my mastrant support rope 3/32” pull up and tie off. If it snags on a limb lower I get out my spider pole and wack and adjust the element n support rope till I get it where I want 😉 no need to climb unless it’s easier then the above ☺️
James, I used a home-brew catapult-cum-fishing rod thing!