G5RV verses Superloop 80
Many operators with small lots, a G5RV is what can fit for the 80 and 40 meter bands. The G5RV is 102 feet long and has a 34 foot
section of twinlead followed by coax into the shack, possibly with some sort of RF choke on the coax. The ends are typically supported by ropes up in
the trees. An 80 meter dipole would be about 134 feet long.
A tiny lot is limited in antenna potential and zoning laws prevent real towers.
RadioWorks “Superloop III” designed by Jim, W4FTU, and refined over the years, is a good alternative
PHYSICAL VARIATIONS
The standard arrangement is shown in Fig. 1. It looks like an inverted delta loop and is 112 feet across the top. It fit on the same ropes as my G5RV used and the coax even started at about the same point in space. The wire is heavy 14 gauge copper. If your space doesn’t quite allow this, the top corner insulators can be moved to shorten the 112 foot dimension; also additional insulators can be added to the diagonal wires to make a rectangular
shape and raise the bottom balun up in the air more. I also added 6 feet of wire to move the resonant freq closer to the band bottoms for digital work.
The loop can also be mounted upside down and slanted if you only have a single support available. As with all loops, the area enclosed is important and so is the average height; the standard inverted delta shape is a very good compromise.
ELECTRICAL CHARACTERISTICS
The “trick” to the Superloop is the 30′ length of ladder line hanging down from the center insulator. This length has been tuned so that appears to be a open-circuit stub on 40 meters; thus the antenna becomes two full-wave wires (at 40 meters) and is commonly referred to as the Bi-Square antenna. On 80 meters, it appears to be a short and the antenna becomes a single wave vertical loop. This happens automatically and no switching is involved.
A special balun is provided which gives a match between the 50 ohm coax lead-in and the higher resistance of the loop. For best matching, a 1/2 wavelength coax is recommended (e.g. 99′ of RG-8X); however mine is about 70 feet into my diff-T tuner and the SWR < 2 points are 3495 to 3787 but the short coax gives a minimum on 40 of 2.05 at 7090 KHz. If you need to run without a tuner, close attention to the coax length will help. The balun is the typical ferrite rod in a PVC pipe with foaming urethane inside. This has the effect of heat insulating; mine works fine on 500 RTTY watts contesting, but real high power may be a problem on RTTY; but those guys all have beams, right?
OPERATING RESULTS
The diagonal wires make it partially a vertical antenna with a nice reduction in polarization QSB. You can possibly double contacts on 80/40 over the G5RV. RITTY can help on the reception. The Superloop tunes up fine on the 20,15,10 bands Antenna, ropes, and coax will run you about $US 135. RadioWorks advertises in CQ and QST and have an interesting catalog.
Copyright and originally hosted at http://larc.hamgate.net/SuperLoop.htm
I’d like to try this antenna but I want to build it. Any more details on the balun or can it be purchased separately?
Thanks for the antenna info.
73 de Jeff
I believe you can build you own balun with some standard ferrite cores.
You can find some interesting baluns projects at dxzone.com
The balun is 4:1
I have built 2 of those antennas and they are working greate, also tried with 1:1 balun and did the best result on 80.
Good luck..
Any questions regarding the superloop please send a e-mail
BR/Goran sm5wgm at ssa.se
I tried it. Wors great with the exception of 20m. It won’t load there……..suggestions??
Hi,
Would anyone give me the measurements of the super loop antenna, and is the ladder
line 450 ohm van gordan with a .95 VF?
And what bands have you been successful on?
73,John,ko6ef
Can anyone give me the dimensions of the superloop antenna I see it’s 112′ across the top how long are the 2 wires that come down from the 112 foot flatop part.Or is it 112′ on 3 sides.Thank You
Use c^2 = a^2 + b^2 to find the dimensions: a = 30, b = (112/2), c is the line descending at an acute angle (the hypotenuse); c = (aprox.) 63.53.
Search the web for Pythagorean theorem. There are some calculators that will give a more exact answer.
I have had the Homebrew SuperLoop up for 9 months now and without doubt far superior to any wire antenna I have had up previous for 80m, 40m, and quite useful for 20m. 15m & 10m. It was only put up as an experimental antenna and will be replaced with a much heavier and stronger one when the warmer weather gets here. Previous antennas were WINDOM, DOUBLE BAZOOKA, DIPOLE. Cheers, 73 – Greg VK2MTC
Do a search on yahoo for Dr.Ace and you will find a site for all the instructions for building this great antenna
Does anyone know if the Super Loop can be modified to work on 160 meters? I am interested in getting mine to work on 160, and don’t really care if I lose the other bands in the process.
As a total newbie to the hobby, I sure would like it if someone could provide a closeup of the ladder line connections/solder points and as well as the design and connections of the balun. I am not so good at interpreting stick figure diagrams yet. Picturres please!
Try this website for aditional specs. http://www.bloomington.in.us/~wh2t/Super%20Loop%20Antenna.htm
Well, I thought I would do a follow up on the 80m SuperLoop – It has been a couple of years now since I first got interested in this antenna design. The first one I made and used was up for 15 months and I decided to build a stronger version to leave up permanantly as I was very happy with its performance (as temporary under test antenna experiment).
The new version I made was using a plastic coated multi strand copper wire – the wire used was classed here in Australia as a 30 amp cable – it has 52 strands and the copper section is 2mm dia – quite heavy wire for antennas, but worthwhile for longevity …. The ladder line section is homebrew of the same wire, with a 50mm spacing. I also run it through a homebrew 4:1 Air Balun that I found plans for on the net – made using twin core wire (figure8) wound on to a 50mm PVC section. Very easy and functional.
The SuperLoop now resides permanantly by way of a 8mm Silver Nylon rope strung up between 2 very tall Pine trees – the loop is attached to the rope with cable ties every meter and the corners of the loop are helped make the transition to the apex by using 2 small (50mm) lengths of PVC 50mm dia, cable tied as well (stops making to sharp a corner for the wire) …
I constantly get unbiased signal reports on 80m + 40m, and am exceptionally pleased with this antenna – I have set up the antenna to be resonant at 3.585MHz and use no tuner for operation here in Australia. I do use a tuner on 40m, 20m, 15m, 10m + 6m bands, with good results on ALL bands.
Talk about Bang for your Buck, this antenna is a brilliant design and have worked many stations all over Europe on 40m 20m etc …. using 100w. I can’t speak to highly of this antenna – Many thanks to Dr. Ace for his website where I found the design. I have told many operators of the design and a few have built them and are getting good results as well.
Not convinced – well all I can say is, BUILD one and try it for yourself – you won’t be dissapointed.
Cheers to ALL – 73
Greg – VK2MTC
How to build a super loop for 80 meters, using a preferred feed, utilizing a “Q-sectionâ€.
Every antenna is compromised to be able to be used as a multi-band antenna with the exception of normal harmonics. With that said let’s make our antenna resonant at 7.30 MHz (40 meters) and this will also be an 80 meter antenna resonant at 3.65 MHz As you can see, we are at one end of the 40 meter band and the other end of the 80 meter band (a compromise), but will play very well on both bands.
The 450 ohm ladder-line stub is going to be ¼ wavelength of the 80 meter band. Which is also going to shorten a normal 80 meter loop by the same length so that we end up with a full wavelength.
Stub – 234/3.65 = 64.1 feet (64 feet is close enough) so we cut the 450 ohm ladder-line to a length of 32 feet… (32 feet X 2 wires = 64 feet). Solder both wires of one end together.
80 meter loop is 1005/3.65 = 275.34 feet less the ¼ wave-length of 64 feet gives us 211.34 feet (211 feet is close enough).
So our antenna wire is 211 feet and the 450 ohm stub is 32 feet long. Now we cut the 211 feet of wire in half and attach one wire of the 32 foot 450 ohm ladder-line to each ½ of the 211 foot (105.5 foot leg). Then solder the other ends of the 450 ohm ladder-line together – if you have not already done so as mentioned above. Now from one end of the loop to the other end we have a length of 275 feet.
Some say to put a 4:1 balun at the feed point and this is fine however a preferred way to feed any loop is with a “Q-sectionâ€. Without the details of the formula, the length of a “Q-section†for 80 meters is about 41 feet and 20.5 feet for 40 meters. We build our “Q-section†using 75 ohm coax. (You can use the 75 ohm coax that is used for your cable TV or satellite). I have used this with over 600 watts with no failures. So we cut our 75 ohm coax to 41 feet and attach it to our loop (dialect to one leg and shield to the other leg), and add a coax connector to the other end.
Now we just use a barrel connector to connect two PL-259’s and then attach the 50 ohm coax to the 75 ohm coax… By using a “Q-section†we are more confident that while tuning our antenna we are not just tuning the balun…. This is some food for thought for those that use baluns.
You can add an air choke to the feed line by taking a large plastic coffee can and wrapping about 8-12 turns around the can… Or take and wrap about 19 feet of coax around 4†PVC pipe.
Summary – 211 feet for the loop, 32 feet for the stub, 41 feet of 75 ohm coax for the “Q-section .
To tune the antenna you would do either the trimming of the stub or the antenna itself remember if you trim the antenna then you have two sides – so if you add/subtract 4 feet then 2 feet each side of the stub, or 2 feet off of the stub…. etc… Good luck and many contacts…
Hello Jim
Would it be possible to take half of your formula to make a 40/20/10 meter loop?
And Also GREAT!!!! Instructions
Hi,is the Balun a 4 to 1 current balun,and am I right in saying that the sides are 71.5 feet long,also does the end of the open wire feed attach on to the balun or just hang there,Id like to build this antenna and would like comments
Hi Richard – the Balun I used is here – http://combotec.com/projects/balun14/balun14.html – It works quite fine (I only use 100w) for me – no problems at all.
The END/S of the open wire line is/are JOINED at the bottom to form a STUB and NOT CONNECTED to the Balun – But connected to the horizontal TOP section in the Middle (CUT the horizontal mid point and join there) and it makes the loop continious with the feedpoint/balun at the bottom.
The easy way to set up the antenna I found is – to pin the middle of the horizontal section on the ground with tent pegs – stretch out the ladderline 90 deg and pin there – cable tie the balun to the ladderline allow an inch or so for clearance between the ladderline and balun.
Then stretch out the rest of the both sides/arms to form the delta, that way you won’t have the ladderline hanging below the apex and you won’t have to much antenna hanging down below the end of the ladderline …
It is quite simple to set up really … Have a go and if you run into any problems check my QRZ site and contact me and I will endeavour to assist.
Cheers, 73
Greg – VK2MTC
Hi I finally got this antenna up and working,I used a 4:1 homebrew Balun,it is working excellent on 80 and 40 metres,any signal that is 7/7 on a Windom becomes plus 10 to 20 over 9 with the loop,havnt used it on 20 yet,if anyone wants more information please email,cheers Richard
If we add the total stub length to the loop perimeter we get a loop of 312ft. like this 112ft horizontal + twice 63ft (the diagonal sides +the 64ft stub(32+32=64) we get 302ft.I would like to add the length of the stub but not sure if we can I know a 302ft loop will not resonate on 80m but loops are forgiving and a balanced tuner can take care of things no problem, but the resonant length for a loop on 80M is around 265 to 270ft.loops as short as 240ft have worked and still working here at N6DBH with balanced feedline and balanced tuner like the Johnson.
fotografierte Bilder als 2 Element für 40 m verwendet Draht ist LFK Draht von ex DG1SWW Neues Rufzeichen ist DK7VK in qrz.com zu sehen