Sorry, not to drag this on longer.......just one last observation. Back to antenna theory and the use of the k factor -- k = length to diameter ratio....showing the thicker the element (lower the ratio) the more the antenna is shortened to obtain resonance. Also, as per the books, the Radiation Resistance is also varied, lower, depending on this k factor. Read up on the details that Chris had mentioned a few insertions back.
495 x k / f MHz = length in feet Note: BVARC newsletter October 2017 The Radio Hotel column is all about broadbanding and the method presented at Dayton in 2017 from Penn State. So if you are looking to broadband your 80 meter sky hook, have a read of that 2017 TRH and the references presented therein. Link to it here...... http://www.bvarc.org/newsletter/201710.pdf TTFN, 73....Rick On Sun, Jan 19, 2020 at 7:31 AM Nizar Mullani <[email protected]> wrote: > That is what I thought. Thanks for confirming that there is no change. > > Nizar > > On Jan 19, 2020, at 6:52 AM, Rick Hiller <[email protected]> wrote: > > > Modeled 80 meter 1 and 2 wire with .1 foot spacing #14 copper at 60 > feet. Open ends and shorted ends. > No, it does not. Minimal change in resonant freq, feed Z and gain. > RH > > On Sun, Jan 19, 2020 at 3:05 AM Nizar Mullani <[email protected]> wrote: > >> Rick, >> >> Chris bright up an interesting point regarding what may be different in >> the antenna if the ends of the wires are connected or not. He says (my >> understanding) that a Cage antenna has the distal ends connected together. >> If not, it is not a Cage antenna. >> >> My question is, if I had a two wires dipole, exactly same length and >> close together, does the antenna behave differently if the ends are >> connected or not? >> >> Nizar K0NM. >> >> On Jan 18, 2020, at 8:10 PM, orin snook via BVARC <[email protected]> >> wrote: >> >> >> Well Done Rick! Much appreciated! >> >> 73, >> KB5F/mm >> ------------------------------ >> *From:* BVARC <[email protected]> on behalf of Rick Hiller via >> BVARC <[email protected]> >> *Sent:* Saturday, January 18, 2020 8:05 PM >> *To:* BRAZOS VALLEY AMATEUR RADIO CLUB <[email protected]> >> *Cc:* Rick Hiller <[email protected]> >> *Subject:* [BVARC] Conclusions of the antenna technical question. >> >> The antenna is a "horse fence" antenna. Google it. 15+ strands of >> #30 stainless wire, separated from each other and woven into a 1.5" wide >> strip of plastic webbing....like a folding beach chair web. >> >> So I was looking for the magic that was claimed. After all y'alls >> comments, one on one discussions and revisiting the web sites marketing >> material and youtube videos, I certainly did not find it.. >> >> In the end, the multiple wires provide only a wider useable bandwidth on >> 80 meters. Other bands too but 80 is the bandwidth eater. No other normal >> antenna attributes are affected. The you tube video shows the antenna as >> a mutiple band 80, 40, 20, 10 antenna and after listening to the video a >> few times it is only by the use of an in shack ATU (tuner) that you get >> "flat" SWR on 40 and 20. (That is another sore subject with me, but later). >> >> 80 meters, the fundamental band of resonance, requires no matching >> network, just like a normal, single wire 1/2 wl dipole. The useable 3:1 >> SWR bandwidth on 80 is pretty good at about 200 KHz...maybe a bit more >> depending on how high you put it up. A single wire dipole bandwidth is >> around 50 to 75 KHz 3:1 swr if you're lucky. >> >> So, in NEC modeling this antenna I did a bandwidth comparative model for >> a single wire and found that a single, copper wire antenna had to have a >> wire diameter of about 4 inches to have the similar bandwidth result. Of >> course, there is no wire 4" in diameter available at Home Depot, so a >> multi-wire "Cage" dipole, as a few had mentioned, is the way to go for >> equivalence. >> >> I guess the benefit of the Horse Feather antenna is that it is a single >> 1.5" wide material that is easily deployed. No putzing around with 15 >> individual wires, just one interwoven web deployment on each side of the >> dipole. >> >> If this is something you think you can use......go to >> >> http://kf4bwg.com/ Horse Fence Antenna >> >> or if you wish to build it yourself....material etc. can be had at >> >> >> https://www.statelinetack.com/item/safe-fence-1-1-2in-wide-poly-tape-200-ft/SLT700567/ >> Fencing material. They also have the end, wire connection clamps >> >> I appreciate all that chimed in to set me straight. Kurt Sterba in >> World Radio Magazine years ago used to write a column debunking the claims >> of the fly by night antenna manufacturers. I wish he were still around so >> he could comment on this horse feather antenna. Also, e-ham has a few >> differing reviews posted. >> >> TNX ES 73.....Rick -- W5RH >> >> Rick Hiller >> *e-mail: [email protected] <[email protected]>* >> >> ________________________________________________ >> Brazos Valley Amateur Radio Club >> Get on the air - 146.94 Repeater >> Volunteer now for the Houston Hamfest >> >> BVARC mailing list >> [email protected] >> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >> >> > > -- > Rick Hiller > *e-mail: [email protected] <[email protected]>* > *Cell: 832-474-3713* > *Physical: 9031 Troulon Drive* > * Houston, TX 77036* > > -- Rick Hiller *e-mail: [email protected] <[email protected]>* *Cell: 832-474-3713* *Physical: 9031 Troulon Drive* * Houston, TX 77036*
________________________________________________ Brazos Valley Amateur Radio Club Get on the air - 146.94 Repeater Volunteer now for the Houston Hamfest BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
