In my recent post, More from Dayton 2012, I reported on the horse fence antennas made by KF4BWG, mentioning that every time I see them, I get the idea to try and make my own. Well, yesterday, I went down to Tractor Supply and bought 500-ft. of 2-in. PolyTape fencing material and some clamps. I even got lucky and got the tape on sale. Instead of $64.99, it was on sale for $54.99.
This evening, I started playing around with it. The first thing I did was to clamp the tape with the clamps I bought. What I discovered is that the clamps really don’t make contact with all the conductors. They tend to bow, and some of the conductors in the center of the tape were open.
To get around that, I used an X-Acto knife to separate the conductors from the tape and bend them back so that they lay on top of the tape. Now, when I tighten down the clamp, I get a good connection on all conductors.
The problem I’m having now is how to connect the Hy-Q dipole center insulator that I have to the tape. What I need is some kind of clamp that will connect the solid copper wire coming out of the center insulator to the tape clamp. Anyone have any ideas? I can see drilling a hole in the tape clamp to secure the copper wire. Not only would that connect the tape to the center insulator, it would take out the bow in that clamp and make an even better connection to the conductors in the polytape.
Chris KQ2RP says
I would get a wire ring connector
http://media.digikey.com/photos/Molex/19070-0040.jpg
that accepts the diameter of the wire from the center insulator and both crimp and solder it onto the wire. Then remove a bolt from the tape clamp, place the ring connector hole in place on the tape clamp and re-insert the bolt through it and tighten.
KB9YFR says
What about a small flat piece of metal between those two bolts. If it ran right on top of the clap it should hold that wire nice and tight. You might have to put a washer under each side to get the right height for the wire thickness.
I am not sure how long those bolts are but you might need slightly longer bolts as well.
Jeff, KE9V says
I think you may be discovering why the gentleman who sells these “ready-made” has a viable business. :-)
Good luck in the endeavor!
73, Jeff KE9V
Dan KB6NU says
Actually, what I’m discovering is that, with a little tinkering, I’m going to have an antenna that cost me less than 25% of what I would have spent on a KF4BWG antenna (not that I’m begrudging him that). And, I’m having a lot of fun doing it.
I’m also glad that I got a couple of my readers to flex their mental muscles a bit. Thanks for the tips, guys!
Jonny says
This may sound crazy, but hear me out. What about using two latches from seat belt assemblies? I’m talking the “old school” domestic auto ones, that had a friction cam in there to fix the buckle on the belt at a specific location.
If you got two of those buckles and ran your dipole sides through them, then bolted each buckle to one side of your insulator, you’d be able to tune it even, assuming that you could get good continuity through the buckle. It would be a tight friction fit so I bet it would actually make fine contact with the conductors.
Dan KB6NU says
That’s not a totally crazy idea. In fact, one of the “accessories” they sell for the polytape fence is a “splicer.” You can use this to adjust the length of the polytape. You can then tie your rope to the end with the “V.”
Jon KF5QHQ says
One recommendation would be to wrap the fencing material around the plate a few times, then clamp it down with the other plate and bolts. I’d probably throw a split ring washer between the plates too.
Being a total newbie to ham (just got my technicians license), I’m not sure how wrapping the material would affect the usability of the setup.
Dan KB6NU says
Good points. In fact, the KF4BWG design does just that. Thanks!
Don Robertson says
Norris lives in the wide open spaces; lots of room for any antenna he desires. City lots – most limited to perhaps a 66 foot long wire-type antenna might be at a disadvantage???
Wanting to operate 4o meters / 80 meters with a dedicated antenna could mean an unconventional layout, yes?? Center pole — four outer poles spaced say 50 foot to 65 apart in a rectangle around the center pole?? So if the center is used for the apex of the “V” then outer poles might be utilized to support the remaining wire?? A “V” with the excess forming a horizontal plane — a’zig-zag’ so to speak?? The pattern might skewed yet very effective for both local and DX?? I dunno — just wonderin’.
Alan says
The centre connector on the KF4BWG version looks as if there may be something inside it a balum perhaps??
Dale Parfitt says
I don’t see that anyone has commented on why this antenna is broadbanded. The wire spacing is not nearly wide enough to accouint for the bandwidth. What does account for it is the extremely lossy, thin, steel wires. If someone wants to send me an accurate SWR plot, I can dsetermine what sized resistor one could place across the center of their dclassic dipole to achieve the same bandwidth.
Dale W4OP
Dan KB6NU says
Hmmmm. I didn’t think about that. I thought it got its broadband characteristics from the width of the conductor. If I recall, the horse fence wire I purchased had 14 separate conductors, so connecting them all in parallel would yield a lower effective resistance.
To be honest, after my unsuccessful attempt to build a 2m dipole with the horse fence wire I purchased, I kind of put this project on the back burner. Maybe I need to resurrect it.
Dale Parfitt says
If you model the horse fence antenna in any of the popular NEC engine based programs, one can readily see the efficiency difference simply by replacing the stainless wires with copper in the model.
The width of the spaced wires is way too narrow to result in any measurable increase in bandwidth that we see with wide spaced cage style antennas.
Dale W4OP
Dan KB6NU says
I keep telling myself that I need to learn more about antenna modelling.
David Ryeburn, VE7EZM and AF7BZ says
For a related point, see the article in Owen Duffy’s blog. Not only can efficiency drop drastically when there is iron or steel around, propagation velocity can change. The 91% loss he cites would account for a lot of bandwidth improvement. But what a price! Makes me all the more appreciative of copper (not copperweld, but real copper) wires for antennas and for open wire feedlines. There are better things to do with one’s QRP rig’s power than heat up iron.
DAVE BEHEE says
Just recently built a horse tape dipole. Mine is 7/8″ wide 8 ALUIMUM conductors. Originally was using 14 ga copper. Band width about 60 khz@ 1.5:1 swr max. Horse tape 105khz @ 1.5:1 max. Here’s the kicker, when wet with rain, the SWR went to 2.6:1 SWR. yes the BW was much better, i was going to buy some 2″ wide aluminum conductor tape for even better BW but not now. These test were all on 40 mtrs.
Will construct a cage type dipole with air spacing…
Bill Miller - K5EAG, Bowie, Texas says
I just heard about the Horse Fence Wire Antenna tonight while talking with some guys on 80 Meters. I am curious about your connection to the feed point. I am going to Tractor Supply tomorrow and see if they carry the wire and look at options on connecting the 2 legs to the center conductor. Since it has been several years since you posted on this site, wondering if you have any new ideas or suggestions.
Dan KB6NU says
I’m afraid that I wasn’t successful at my first attempt at making a 2m dipole and abandoned the project. I still have the big spool of horse-fence wire. I was just looking at it this morning as I was lifting weights.
I just took a look at the link in that old post. It now forwards to a porn site, so I’ve removed that link. I’m guessing that KF4BWG is not selling these antennas anymore.
Kevin KD6LYG says
This got my attention. I just saw a post on social media that had me searching out the horse fence antenna. Then I got to thinking, why not use the flat copper wire for an antenna? I did a search on “flat copper wire antenna” and didn’t see anything on it. I would think that building an antenna out of flat copper wire would be very broad-banded.
Dan KB6NU says
If you mean flat strap, I think it would, too, but it would be kind of expensive.