# "SEMI-LOOP" -- FOUR OR SIX Supports? Configuration Query -- Layout Included

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by WD5JOY, Apr 8, 2012.

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1. ### WD5JOYHam MemberQRZ Page

I have SEVEN POLES in the ground and hopefully my little diagram is clear enough to show their relationship and distances from one another. I have labeled them as: "'A' --- 'B' --- 'C' and 'X' and shown nominal distances from each pole (+/-).

POLE 'A' in the CENTER is approximately 35 FEET IN HEIGHT and closer in distance to one end versus the other by approximately 10 feet due to placing it in the ground to avoid concrete already in place. I believe POLE "A" is close enough to "center" however - it will likely NOT BE part of the "LOOP WIRE" layout.

DISTANCES from the FOUR POLES marked as 'X' are 60 FEET and 52 FEET times two sides each respectively - yielding a TOTAL PERIMETER LENGTH of 224 FEET WITHOUT USING THE TWO ADDITIONAL POLES AT EACH END..

DISTANCES from poles marked as 'B' and 'X' & 'C' and 'X' are right at 25 feet in EACH DIRECTION (DIAGONALLY) and total 100 feet.

(Double checking MY 'math' )

60' x 2 = 120' + 52' x 2 = 104' resulting in a total length of approximately 224 feet if ONLY FOUR POLES are utilized.

Using the additional pole at ONLY ONE END would ADD approximately 50 FEET to the above total -- for approximately 274 FEET TOTAL OR if using the additional pole at BOTH ENDS a TOTAL LENGTH OF APPROXIMATELY 324 FEET. .

These 'lengths' are rounded down - however, IF USING ALL SIX POLES (excluding the center telescoping mast) - I should have a MINIMUM of 324 FEET in TOTAL LENGTH IF I USE ALL THE SUPPORT POLES (6 TOTAL) which I would seem to have to do IF I want to cover 80 meters with a bit to spare.

Now that I have all these "numbers" running amok in my head ............... "WHATCHA THINK folks"? Did I include enough info to gather input "pro and con"? I can "see" the wire in the air ........... but, it's been so long I'm not certain if my vision is clear! ALL INPUT APPRECIATED.

I would "like to" FEED IT WITH COAX it in one of the FOUR CORNERS using a BALUN (1:1???) at the TOP where the wires come back together. I would like to use LADDER LINE for approximately 25 feet to the rooftop and THEN use COAX at approximately 25 FEET LENGTH TO THE RIG/TUNER. Not ideal to use COAX --- but it may be a necessity due to the LADDER LINE not being an option.

HEIGHT ---- also NOT IDEAL ---- will "be what it will be" ---- anywhere from 15 feet to 25 feet high depending on a multitude of things out of my control.

THANK YOU ONE AND ALL ---- hopefully my feeble old brain has allowed me to make this somewhat "clear" on this 'Easter Sunday'!! A MIRACLE INDEED!

Don

2. ### KB4QAAXML SubscriberQRZ Page

I can't even begin to understand that with my fozzled brain this morning.

A 'loop' is one piece of wire connected at both ends to the radio.

What shape you have it arranged in is not critical. Try not to get it too 'long' with opposite sides too close together.

Regarding height....the old ham nemesis.....Do what you can, higher is better up to 1/2L.

'Nuff said.

3. ### WD5JOYHam MemberQRZ Page

"Fozzled Brains" ...... I know the feeling!

IF I made it a 'rectangle' of sorts - using only the four "X" posts - the 'sides" would be 52 feet apart on two ends and 60 feet apart of the others with the resultant extra EIGHT FEET in length on two sides . Acceptable I believe ..... UNLESS I try and add more "wire" using poles "B and C" making it look like an "arrow-head" on each end. I don't believe this would be an issue -- but then again --- I still look for "Snata Clauz" in December. I saw one example with SEVEN SIDES and the author swore it "worked like a charm"; but, what else could he say after all the work of putting it 'up'!

I know the "coax and balun" versus "ladder line" will be a big point of discussion IF this takes off and am curious as what folks say. As noted in the OP --- I would love to use 'ladder line' - but it IS an issue I don't think I can get around - COAX will probably be the only way to go. ALSO --- some say, "NO BALUN" while other says a "1:1" and still others says a "4:1" ..... adding to my corn-fusion! I squashed two Easter eggs while staring out at the poles in the back lot this morning! Held my mouth really funny too; AND squinted one eyeball!

4. ### WA6TXUHam MemberQRZ Page

I have a 500 foot horizontal loop.It is 500 feet versus the 272 necessary for an 80 mtr full wave loop. But, as you say, it is what it is. The distance between my trees dictate the wire length. I could use a lot of dacron line instead of the wire and make it a smaller loop. But what a waste of expensive dacron line. I'll take the longer wire any day. Like you, my loop is only 15 to 25 feet high. That is where the problem lies. It needs to be higher, since at the current height it is a cloud burner on most of the bands. To get any desireable angles for DX, it just has to be higher. I am going to raise it to 40 feet at all corners, by shooting for higher branches in my trees. Since you have poles, can you not just add a ten foot 2X4 at each pole? The modeling programs and my knowledgeable ham friends all say that that extra 15 feet in height will make all the difference in the world. I am feeding it with 450 ohm ladderline all the way (no coax). I have a 4:1 balun built into my antenna tuner (MFJ). At the height I have, it does work fairly well and is quiet on receive (no ambient noise), but I am shooting for the extra height. Dave. WA6TXU.

5. ### KB4QAAXML SubscriberQRZ Page

Do what you can.

If your tuner will load it, then fine. Ladder line is great. Coax is fine; with A balun is ideal, but not critical.

Again, shape is fairly unimportant.

6. ### WD5JOYHam MemberQRZ Page

The old mind is runnin' wild - obviously too danged much time on old wrinkled hands!

Using the above pretend diagram - with the 'center pole' - 'A' at 35 feet --- start off with an 'Inverted-V' -- each"end" attached to the poles (via insulators) on the "narrow side" of the rectangle (the 'X' POLES) which are 15 feet high.

So ...... 35' HIGH in the center and 15 HIGH on the ends --- each "leg" roughly 45 FEET LONG and using up approximately 90 FEET of wire.

THEN: From each of the two "X" POLES that now form the "V" run LATERALLY (horizontally) to the next "X" POLE across from it adding 22 FEET to the 'leg'; repeat on the second 'leg' on the opposite side (+/-) of the rectangle (making a funny looking "Z" on each side). Each 'leg' would be 67 feet +/- for a TOTAL COMBINED LENGTH OF THE "LEGS" at roughly 134 FEET in a STRANGE CONFIGURATION!

Instead of simply "drooping" the ends of each "leg" of the "Inverted-V" VERTICALLY -- they now run HORIZONTALLY and form that "funny 'Z" looking pattern I see in my tiny mind! .

Forming a "LOOP" would require much more wire while this configuration -- not really a "Inverted-V" --- would require only 134 FEET +/-.

The part that puzzles me is the "end portion" of each "leg" now running 'horizontally' instead of "drooping vertically". Will a 'strange pattern' be the result? Probably - but then again maybe no stranger than that resulting from a "LOOP" that is too close to the "earth" at ONLY 15 FEET HIGH overall.

Yes. I DO seem to have too danged much time on my hands!

Last edited: Apr 8, 2012
7. ### KB4QAAXML SubscriberQRZ Page

Ok, so you put up a dipole with a 'Z' configuration and it has a non-standard pattern.

It's not bothering anyone!

8. ### WD5JOYHam MemberQRZ Page

Gad I hope not! However ............ those two 'legs' that make the horizontal turn ......... won't the "fold back" on itself being somewhere around 45 degrees be somewhat counter-productive? I'm just running different configs for wires on the poles to see what I can come up with; nothing that's never been done before I'm sure ........... but not by 'me'. Heck - it's gotta have a 'bother factor' or a dead-bang negative somewhere me thinks. Some of my ideas ......... ummmmm ........ well, they 'suck' ....... even for an old guy!

I still am leaning towards the one that somewhat resembles a "LOOP" ............ but I've never mastered the whatchmacallit program that analyzes antenna ideas. Wish I had - but not right now. The only "new stuff" I have mastered of late is hooking those little tabs on 'DEPENDS"! Not really - but at times like this I feel that way!

All this wire --- all these poles --- searching for a place to 'hang' ........... even if it isn't 'optimal' by some standards. Maybe after the Easter Happy Holiday the inventive minds will spring into action and I'll have a new and improved project to fill in the free time ---- which nowadays is a LOT!

Someone had an 'idea' .......... but the PM said something about, "hams being serious when asking questions results in real answers"! Imagine THAT ------- I gotta be "stuffy" or no answers per HER standards! A 'lady ham' - bustin' my chops! Sheesh!

9. ### W6OGCHam MemberQRZ Page

Why not run a 6 legged loop, fed it with ladder line to the entrance of your QTH, with a balun at that point, then coax into the "shack" with a tuner?

This would be B-X-X-C-X-X-B, either way. The real trick is getting it higher than 15', as the higher the better.

10. ### WA4FNGHam MemberQRZ Page

I think everyone is getting all wound up over the supports, exact length, etc. No where was it mentioned what bands this antenna should work. Personally, I think feeding a loop like this with coax is just going to give you grief. You most likely will have wild variations in the match, perhaps more than your tuner can handle, as well as the accompanying loss in the coax. The beauty of the "sky wire loop" is feeding it with open wire line. If you could run open wire line from the antenna to the house, then a remote auto-tuner at that point could make this a good setup. You could run coax from the tuner to the rig.

Not trying to persuade you to not put up a loop, but since you want to feed an antenna with coax -- maybe something else might be the better antenna. With all those supports you could put up any combination of single band and fan dipoles to cover your bands of interest.

11. ### WA6TXUHam MemberQRZ Page

I agree with you that open line feed (I use 450 ohm ladderline) is the way to go with a horizontal loop. The advantage of the long loop (270 ft or longer) over the fan dipoles is that the gain is really good on the higher bands (since it is multiple wavelengths long on those bands). I have a 500 ft wire loop up at about 20 feet. It does very well on 10, 15 and 20 (because of the gain producing multiple wavelengths). My one regret is that it is only 20 feet above the ground. I am about to rectify that by trimming some tree branches and getting it up to 40 feet above the ground. With a horizontal loop, especially, it is about height, more than the length of the wire. Of all the wire antennas, the horizontal loop is really great in my book, especially with open wire feed. Granted, with a large loop there are great lobes AND great nulls. I will take the large lobes (great gain), and the large nulls (can't hear em). The ones I can't hear, I really don't worry about them. And the reception overall is pretty noise free on all bands! Dave WA6TXU.

12. ### WD5JOYHam MemberQRZ Page

Dave I wish I could get a LOOP higher than supports allow - but I am only dreaming - it is not possible, so I think I will experiment with other dipole-types and see what happens. Less work in the short term - more work in the long run, but the odds of hitting a good combo seem better considering the height issues AND the coax feed-line limitation I face. An in-between solution that will be better than seeing those poles sitting naked and collecting only sun, rain and the gawd awful winds. If nothing else - it will keep me moving about as opposed to sitting and playing when I strike the magic setup that in reality ........ I don't REALLY need. It's a 'project' and not much more.

Don