The AM Forum

 In order to replace the leg of my dipole that broke last winter, reaches out to my neighbors yard. Spmehow Ed managed to get away with it but I've already had one run in with them. Don't desire to risk another.

My thought is to shoot a Zepp straight out into the woods, I've got a tree out front that's at least 75-100 feet high. The highest I can get the feed point is where I'm shooting for. The end may slope as the property goes down hill..

Would this perform as well as a dipole? Better than a dipole? A Windom is also an option. I'll feed them with 450 ohm feed line.

I've never experimented with anything other than your average dipole and I'd like to be able to put something up and use it effectively and avoid allot of tinkering and swapping for optimum performance if I don't have to.

I've heard allot about Zepps but I don't know how much is true, how much is hype.

I ran a 300 foot Zepp that worked great off the far end on 20m but you have to live with plenty of RF in the shack. You also need to have a good ground. I was in my second floor bedroom with the tuner in the closet the end of the antenna came in through the attic. How about a Vee at least it is balanced.

My problem is the house sits in the right front corner of an 11 acre lot. 30' to the right from where the feed point would be is the property line. To the front is the road and power lines. I've got all that space behind me that nobody can say squat about. Grounding is not a problem, I'm on the first floor, an 8' ground rod sits right outside the window. If need be I could put the tuner in the shed and run coax from the shack to the shed. The shed also has an 8' ground rod beside it. The house has aluminum siding as well. My goal is to get as much altitude as possible. With a Dipole or Vee I can get the altitude but the angle might be too tight and there are really no decent sized trees to the left to tie off one end. Yet behind me the property goes nearly as far as the eye can see. At least as far as terrain is concerned. The property layout here is strange I know, but oh well. If worse comes to worse I could sneak a wire up in the neighbors tree at night. At least then I can run a near flat 450 fed dipole or G5RV.

I'm running a 60 degree Vee on 160m that works pretty well. I need to drop two more trees in the woods before I can put the dipole back up.
I had the same problem one tree in the front yard looking at the woods in the back yard. A balanced antenna is a happy antenna.

Yes, by all means run the coax out there to set up a center fed, balanced antenna. It's well worth the effort.

Lay the coax on the ground for the Winter and next Spring cut a trench with some PVC pipe for the coax underground.

As Frank said, yes, the end fed/Windom stuff will work, but it becomes more dependant on grounding and creates potential RF in the shack. A balanced horizontal antenna doesn't care about the ground system and just wants to work... ;D

73,
T

11 acres, I wish I had your problems. Get the antenna away from the house
and QRO. With all that land you could put up coax fed BB dipoles for each band
or 2 element beams .

11 acres :o, cheses Christ, I'd have an array of sterba curtains or some other land hog antennas up by now. I tried to put up a mosley 67b and the 40m el's were swinging over the neighbors house. They didn't believe me when I told them it was a clothes line turnstyle.

Yea, sounds like you got it made there... 11 acres... if I had 11 acres, I'd have rhombics and Vee beams up in all directions. Back when I had that rhombic pointed at South America, I'd get in there with the slopbuckets and really rub it in. I'd say, there ain't a slopbucket in North America that can touch me . Heh, heh, no sir, no there wasn't.


http://www.amwindow.org/audio/mov/w8vyz.mov

I agree with Frank. Uee coax (or open wire line) to get to where you need to be, and then put up a dipole or an array or whatever. USE that 11 acres. You could be WHIRL WIDE!

 ;) That sound clip has been played and replayed so many times on the air in So CA that I know it by heart:

I'd say, there ain't a slopbucket in North America can bother me. Heh, heh. Never was!

With 11 acres... hmmmm..

I'd run a coax to the center. Then run 12 beverages out like a spoked wheel. (every 30 degrees, with relays to select the right one to the single coax) You'd hear whirlwide on 160 and 75M in any direction.

Next put some towers on the perimeter away from the beverages and go to town on transmitting ants.

T

Randall,

You never did tell us what HF bands you want to be on.

Huz,
I had a 2 wire rhombic 125 feet on a leg facing VK / ZL I worked them like locals on 20 meters.
The old 4-1000A with Heath twins rocked. It was only up 25 feet but still played well.
I agree if I thd that land Vee or rhombic.

Duplicating the tom vu beverage system would be worth trying.

you mean "WHIRL WIDE AUDIO DRIVE IN THE MOEBEEELLLLL!!!"

Tom, what do you mean>>>Hmmm, 11 acres? Don't you have like nine 200 foot towers?

The zepp should be completely isolated from ground using an inductively coupled tuner.  Cut the flat top to exactly a half wave at the frequency where it will be used the most.  At that frequency the radiation cancellation at the feeders will be the most complete.  At frequencies further removed from the resonant point, the system should still tune to resonance, even thouh there will be more feedline  radiation.  In should still not be a problem.

Sometimes the end fed zepp is the best solution when it is not practical to run the feedline to the midpoint of the antenna.

If the system is in resonance and the primary and secondary windings on the tuner are properly isolated from each other, there will be no common mode current on the feeders, and no more rf in the shack than from a properly balanced dipole.

This antenna will not work properly with a pi-network, L-network or T-network type unbalanced tuner with balun.  It needs to be inductively coupled so that the tuned circuit that feeds the transmission line can completely float from ground.

If the feeder is a quarter wavelength, the feedpoint will be low-Z.  One trick with a link-coupled transmitter is to cut the feeder slightly shorter than a quarter wavelength, and put a variable inductor in series with one feeder.  Adjusting the inductor will bring the link coil into resonance with the feeder, and it will load fully with a minimum of coupling between the link and the tank coil.  This allows use of a small variable inductor instead of a full-fledged tank-coil type of antenna tuner.   However, this will work only on one band. 

The end-fed zepp was the only antenna I was able to use when I operated from Cambridge, MA and from Houston, TX.  Never had any rf in the shack at either place.

Well,
Here's the deal on the property, I rent the house which is part of two lots. The first lot being about 1-1/2 acres, the second lot behind it is about 10 acres. The land lord has literally said he doesn't care what I do with the house and or property, providing it's legal of course. But the catch is that the property is for sale. I'm allowed to live here until the property sells. So, basically he's told me not to invest too much in the house because I may loose it if someone buys the property. (It's been on the market for a few years now and hasn't sold so I'm not too worried.) The house itself is literally a shack! It's a small house but suitable for me since I'm single. There's a post here on AMFone about ugly houses, well.. Lets just say this house could be the poster child! The land lord won't sell one lot without the other, because the back lot is land locked. Thus both must be sold together. For quite a large chunk I might add!

As for the back lot. It's untamed woods, there's briar's back there that could swallow a man whole and scattered trees that would make setting up multiple antennas in any uniform pattern hard without zig zagging all over. So I doubt I'll be doing too much by way of stringing rombics and dipole arrays.

I'm just looking for a quick solution to get on 75, maybe 160 in the future. Yet I want a decent signal. Another alternative to a straight shot Zepp might be a lazy L dipole perhaps even an inverted L. I'm just looking at all the options that might be useful to get the most altitude and the best configuration to get a good signal on at least 75. Due to the slope of th back lot, which slopes down to a creek then up again some ways back, There is one tree which would get me the most altitude but that tree happens to be an old Oak in the front yard. It's around 75-100 feet tall so If I can shoot a good line up as high as I can get it that's a great center point.

I'll load whatever I set up with a Johnson Matchbox so it's unbalanced in and balanced out. T/R switching can easily be done here in the shack if I need to mount the tuner remotely. Metering would be another issue, I guess I'll have to put a meter in the shed and the shack to tune and monitor since I can't do both with one.

Hey, Randy, I just had another thought. What about a horizontal loop? Put one corner of it right at your house, since it will actually be a square or rectangle instead of a circular loop. You can feed it with a short run of ladder or open wire line. If you make it a full wave on 160, it will play pretty well on the rest of the higher freq bands. It should be much easier to feed than an end-fed half-wave, and you'll be much less likely to have 'RF in the shack' problems.

I ran a 133 foot End-Fed-Zepp from this house for years.  It worked very well, and I never noticed any unusual feed-line radiation.    I ran 450 ohm line to it.   It was up about 25 feet or so, and  snaked around the perimiter of my property (which is a tiny city lot), out to a tree, thence 90 degrees to a pole, another 90 degrees out to the eaves of the house and finally one last turn out to the chimbley (as my neighbor calls it).

I worked all over the US on it and even worked the UK.  Finally fell down in the ice storm of 1998.

My first linear was an 811 then a pair. I got brave and tried SSB. Burned my lip on the mike if i got too close. I even got a buzz off the key. I did have a poor ground because my Dad wouldn't let me drill a hole through the second floor wall and run a ground wire down the side of the new addition.

hehe A friend of mine who shall remain nameless had his shack in his room upstairs.. He was tuning up a DX-60 with a random wire and tuner.NO GROUND! He keyed up as soon as it peaked power he heard his dad hollering assorted unsavory words.. He went downstairs to see what was going on and his dad told him the TV just blew up! I guess the poor ground and the random wire antenna must have somehow blew up the front end in the tele! From that point on the TV would receive no more! Black screen, and no sound. Of course he made up a few excuses and knew nothing of the reason as to why the TV would take a dump so sudden..

My first antenna was unbalanced, and personally since then, I too have remained essentially unbalanced.

As Johnny Novice, I had my Command set operating into a bamboo pole wound with a couple hundred feet of # 14 wire up on the roof. That was one heavy pole! It was fed by 75 Ohm Coax with the shield going - well nowhere...I was on the roof and did not have a ground. Instead I grounded the chassis of the ARC-5 with the center screw of my AC outlet - a fine business 2nd story ground.

This clever antenna arrangement was inspired by the 1970 ARRL Handbook which was preaching the helically wound continuously loading mantra. As a modern 70's Johnny Novice, I shunned the simplicity and primitiveness of a dipole or Zepp. I figure there was some pretty good radiation going on because I worked a VE2 on first try.

My dad yelled that the lights were going on and off downstairs as I keyed the rig.

Mike WU2D

i have used the end fed Zepp at numerous stations over the years with excellent results. i only had link coupled tuners on them and they were all a half wave or longer. the feedline was usually at least a quarter wave long. attempts at this with short (like 1/4 wave) antennas, or short feedlines still worked but were RF in the shack prone. any of these that were 1/2 wave or longer ever needed much or any of a ground, and as my father taught me (try it it works!) put an RF ammeter in each leg of the feedline and if all is well they two meters read the same. best one i had was about 500 feet long and 50 feet up out over my uncle's cow pasture. i was the Novice DX king of 15 meters in the summer of '70 with it.

As a kid, I ran a 6AU5 phono oscillator on 1250 kHz into 100 feet of bell wire terminated with an aluminum "flying saucer" sled hung in a pine tree. No ground or counterpoise. I got a "Worked All Neighbors TV Sets" award with that one.  :D

My Friend Billy and I did the same thing with the LO of a big old radio to jam all the local AM radios. Man did his sister get ticked off when she figured out that is was us.

Talking about RFI, sometime back when I actually owned a Viking II, every time I keyed on 160M the phone in the shack would ring. I'd pick it up and there was nobody there. I key up again, it would ring again! It was not a real bell phone but one of those electronic cricket sounding phones. A 220 puff cap across the line and a ferrite core fixed it, but come to find out I wasn't the only one. A next door neighbor had the same problem. I wasn't about to admit that I was the cause of it! I guess that's one of th downfalls with today's cheaply designed electronics, and RF in close quarters!