From Cecil_A_Moore@ccm.ch.intel.com Mon Oct 28 16:21:59 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34924-42440>; Mon, 28 Oct 1996 11:21:58 -0500 Received: from marceau.fm.intel.com (marceau.fm.intel.com [132.233.247.8]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id LAA62026 for ; Mon, 28 Oct 1996 11:21:49 -0500 Received: from fmmail.fm.intel.com by marceau.fm.intel.com (8.7.6/10.0i); Mon, 28 Oct 1996 16:01:07 GMT Received: (from ccmgate@localhost) by fmmail.fm.intel.com (8.7.4/8.7.3) id HAA20795 for qrp-l@lehigh.edu; Mon, 28 Oct 1996 07:59:30 -0800 (PST) Received: by ccm.fm.intel.com (ccmgate 3.2 #2) Mon, 28 Oct 96 07:59:30 PST Date: Mon, 28 Oct 96 07:52:00 PST From: Cecil A Moore Illegal-Object: Syntax error in Message-ID: value found on fidoii.cc.lehigh.edu: Message-ID: Now for the question - The lowest SWR I get is 1.9:1 reading which is >also at my desired Freq. (7.000 MHz) the Z is 33. This is also the >lowest Z reading. Why isn't the Z = 50 and the SWR closer to 1.1 if >this is my closest match to my antenna? I can find a Z of 50 and a SWR >of 1.9 at 7.100 MHz again with Z = 50 why isn't SWR 1:1. >Brad Mugleston - KB0ROL Hi Brad, A delta loop is supposed to have 100 ohms feedpoint resistance at resonance. Sounds like you hit it pretty close. SWR = 100/50 = 2 I just went through the same thing and wound up with a triangular loop. You can get 50 ohms feedpoint resistance from a delta by changing the lengths of the sides. 59ft +------------------------+ \ | \ | \ | 20ft \ | 62ft \ | \ | \ | choke + <==[][][]==== 50 ohms It started out as a delta and you can see how I changed it to a triangle. It has about 3dBi gain and works on 20m, 15m, 12m, and 10m with an antenna tuner. 73, Cecil, W6RCA, OOTC From wb2vuo@juno.com Wed Oct 30 05:19:40 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34838-20230>; Wed, 30 Oct 1996 00:19:30 -0500 Received: from x3.boston.juno.com (x3.boston.juno.com [205.231.100.22]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id AAA218940 for ; Wed, 30 Oct 1996 00:19:28 -0500 Received: (from wb2vuo@juno.com) by x3.boston.juno.com (queuemail) id WAA18280; Tue, 29 Oct 1996 22:35:19 EST To: qrp-l@Lehigh.EDU Date: Tue, 29 Oct 1996 18:16:55 PST Subject: W6RCA Triangular Loop on Other Bands Message-ID: <19961029.181701.4727.0.wb2vuo@juno.com> X-Mailer: Juno 1.00 X-Juno-Line-Breaks: 1-2,8-9,19-20,26-27,30-34,36-47,50-51,53-57 From: wb2vuo@juno.com (William K Hibbert) After reading Cecil, W6RCA's post on the triangular loop for 40 Meters, I decided to play with the design on other bands. First off, the design, fed at a bottom corner, should look more vertical than horizontal, so I scaled one for the 2 Meter band to check out this premise. The vertical side came out to 11.75", the flat top to 34.75" and the diagonal to 36.5 ", total length of 83". Resonance showed up at about 144.5 MHz, within reason allowing for the relatively `large' conductor size (#12 solid wire). Now for the checks. I tie-wrapped the flat top to a 3/8" fiberglass electric fence post, which was forced into a hole in a 60" length of 1" CPVC pipe. The feedpoint was attached to a small rectangle of perfboard, held off the PVC with a 6" length of the 3/8" fiberglass. First off, I rotated the CPVC mast for a pattern check, utilizing the local repeater (K2SA/R), and found a clean bi-directional pattern, but with asymmetrical nulls in the plane of the loop. I then put the mast horizontal, with the flat top now vertical, and swung the mast through 360-degrees. I saw no real change in the pattern, but the nulls were more symmetrical. The signals were, for all practical purposes, the same. It seems, from this rough test, that the actual polarization is oblique, between vertical and horizontal. This may be an anomaly caused by coupling to objects in the near field, and I really don't have the means of eliminating this possibility. However, regardless of the "true" polarization, the signals were equal to my Copper-Tube J-Pole with both at an equal height (a back porch roof, up 15 feet...) I will next try this design on 6 and 10 Meter FM. If you want to try out a resonant, single-band version, here's the lengths, scaled from the original design... FREQUENCY VERTICAL FLAT TOP DIAGONAL 1.85 MHz 77 ft 226 ft 238 ft 3.70 MHz 38 ft 113 ft 119 ft 7.10 MHz 20 ft 59 ft 62 ft 10.10 MHz 14 ft 41.5 ft 43.5 ft 14.10 MHz 10 ft 29.7 ft 31.2 ft 18.10 MHz 7.8 ft 23.1 ft 24.3 ft 21.20 MHz 6.7 ft 19.8 ft 20.8 ft 24.90 MHz 5.7 ft 16.8 ft 17.7 ft 28.40 MHz 5 ft 14.8 ft 15.5 ft 29.40 MHz 4.8 ft 14.2 ft 14.9 ft 52.50 MHz 32.4 in 95.5 in 100.5 in 146.0 MHz 11.7 in 34.5 in 36 in I used a couple of snap-on ferrites from the local computer shop for the "Sorta-balun" on the outside of the RG-8X. I don't know if it did anything, but they were there, so I used them... It would be nice if someone could model this loop and see what the polarization actually "is"... 72/73, Keith, WB2VUO, QRP-L #582 Trustee, KB2YTW/B 10 Mtr Milliwatting Beacon (250 mW @ 28.2870 MHz) "In the Depths of the Great Bergen Swamp...FN13ac" From cebik@utkux.utcc.utk.edu Wed Oct 30 14:20:37 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34893-5896>; Wed, 30 Oct 1996 09:20:35 -0500 Received: from utkux4.utcc.utk.edu (UTKUX4.UTCC.UTK.EDU [128.169.76.11]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with SMTP id JAA125391 for ; Wed, 30 Oct 1996 09:20:31 -0500 Received: from localhost by utkux4.utcc.utk.edu with SMTP (SMI-8.6/2.7c-UTK) id OAA26095; Wed, 30 Oct 1996 14:10:27 GMT Date: Wed, 30 Oct 1996 09:10:26 -0500 (EST) From: "L. B. Cebik" X-Sender: cebik@utkux4.utcc.utk.edu To: William K Hibbert cc: Low Power Amateur Radio Discussion Subject: Re: W6RCA Triangular Loop Models (very long--sorry) In-Reply-To: <19961029.181701.4727.0.wb2vuo@juno.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Modeling the W6RCA Triangle for 40 Although I did some initial modeling on the W6RCA triangle for 40 and reported on it to this list, KB2YTW's 2-meter experiments renewed my interest in the antenna. So I went back to the modeling machine--and tried to make some comparison's that will permit builders to evaluate the design as it pertains to their own situations. One of the difficulties that crops up when folks ask for models is that very often, the materials are not completely specified. Hence, I am not certain whether W6RCA used bare or insulated wire for his design, what his ground clutter situation is, etc. Therefore, the models may not yield exactly his dimensions. All models used #12 bare copper wire above medium ground conditions. NEC-2 is limited to modeling over presumed clear flat ground. One can create wire models of structures, but one would go through that process only for special purpose analyses of specific, unique sites. The antenna I modeled is the W6RCA triangle, a right triangle with a vertical leg, a top horizontal leg and a sloping hypotenuse, fed at the bottom. For comparison, I modeled a half square, which amounts to a horizontal half wavelength wire (a phasing line) with two vertical quarter wavelength wires dangling, one from each end, fed at an upper corner. I chose the half square for comparison because it is the best of a class of antennas that includes the equilateral and right angle delta loops, all of which show considerable vertical polarization without use of radials, counterpoises, etc., being closed loops or near relatives. (How the half square fits in here is a matter for a theoretical discussion of some length, but it does fit.) Both antennas were modeled with a minimum height of 30' with the topmost point a matter of the final modeled dimension. Both antennas were also modeled for 40 meters (7.1 MHz) and for a good coax match. This last strategy does not yield the absolute max possible performance, but the difference is not operationally significant, especially in light of the losses that might be experienced using a special matching method. Using W6RCA's dimensions, I found a low R (25 ohms) with considerable X. So I adjusted the dimensions for a good resonant match on the model. The vertical went to 30 feet long and the flat top went to 55 feet. In this antenna, increasing the vertical dimension increases feedpoint Z, while shortening it does the opposite. Feedpoint Z of the final model was 43 ohms resistive. The half square dimensions are also optimized for coax match, with a horizontal wire 69.9' long and end verticals of 34' for a feedpoint impedance of 47 ohms resistive. With a 30' minimum height for this comparison, the triangle topped out at 60', the half square at 64'. Both antennas radiate essentially broadside to their horizontal wires. The triangle's maximum gain is 2.4 dBi, which is better by a half dB than the right angle delta, which is a bit better than the equilateral delta. However, because the triangle is not a balanced configuration relative to currents or fields, there is considerably more higher angle horizontal radiation than with the deltas. Models demonstrate this by showing the horizontally polarized component of the pattern as a typical dipole figure 8 pattern. The angle of maximum radiation is 20 degrees, and the radiation at 10 degrees is about 3 dB down from that figure. Interestingly, the vertically polarized portion of the pattern is almost identical to that of the deltas. The front-to-side ratio of the oval azimuth pattern is about 5 dB. Compared to horizontal dipoles and loops, the triangle has a much lower angle of maximum radiation, but it also has enough higher angle radiation for shorter path QSOs. The half square's maximum gain is about 2.6 dBi. However, its horizontally polarized radiation takes the form of a cloverleaf of lobes so that in the directions of maximum radiation, the antenna shows strongly vertically polarized radiation. High angle radiation is considerably less than with the triangle, and the angle of maximum radiation is 15 degrees, with about 2 dB less at 10 degrees above the horizon. Note that the take-off angle comparison is only possible by setting certain parameters equal, such as minimum height. These angles will get lower as either antenna is elevated and higher if the antennas are lowered. The half-square is likely to have less QRM and QRN from shorter high angle paths and hence slightly quieter long paths. However, it may also miss some shorter skip QSOs. Note that I neither recommend nor disrecommend either antenna. Both are comparable, and the decision to build either may depend on factors well outside of the modeling exercise, such as terrain, available supports, etc. Keith's 2-meter experiments are part of what whetted my appetite to return to the triangle. My 2-meter 146 MHz bare #12 copper wire in free air with no PVC, etc. around model ended with dimension of 14" vertically and 36.5" horizontally, and that netted a feedpoint Z of 26 ohms. The pattern is dominated by vertical polarization, with horizontal polarization about 10 dB down. (Remember that a 2 meter antenna over 2 wavelengths up (13' or so) will begin acting like an antenna in free space with respect to stability of the feedpoint impedance and pattern components.) Gain is similar to models I have made of deltas in the same position. The pattern is a large oval, with the sides down about 7 dB. Perhaps a superior antenna for vertical polarization in a bidirectional mode is the half-square with the ends pointed up or down as one prefers. Pointing them up makes that antenna easier to feed, since the coax is not directly in the antenna field as a competing element. About 40" horizontally and about 21-22" vertically, pruned to resonance, will yield something so close to 50 ohms that the SWR will be almost imperceptible at 146 MHz. The 2:1 SWR bandwidth will be the 2-meter band. The pattern of this antenna is a pure figure 8, with side nulls at least 3-4 S-units down (models show them at 30+ dB, but I cannot build that precisely). If you have adjacent channel interference, this antenna will null it out and even make strong repeaters noisy in the null. It may also be useful for VHF fox hunting. Its gain is about a dB higher than the deltas and triangles, but that is less important than the side nulls. The reason I have this data on hand is that I just sent an article off to VHF magazine (CQ's new mag) on the half-square for 2-meters, and my working model is hanging in my shop. It uses a thin wall PVC support frame, but in such a way as to interfere least with the antenna wire, all of which is in the clear except where it passes through holes in the ends of the PVC. The antenna is pure house wire and scrap from other antenna projects. Sorry to be so long, but a number of folks have 2-meter interests--and modeling comparisons requires that one set up all the relevant parameters so that the comparisons are meaningful. It is easy to say that "I got good results," but always one has to ask "Compared to what?" whether that is a standard or another antenna. Only if one specifies all the relevant details of a comparison can others evaluate the evaluation. Take nothing on faith with antennas--always get more details until you are sure you understand why things work the way they do. Then you can better predict your own success in putting up the next antenna. -73- LB, W4RNL L. B. Cebik, W4RNL /\ /\ * / / / (Off)(423) 974-7215 1434 High Mesa Drive / \/ \/\ ----/\--- (Hm) (423) 938-6335 Knoxville, Tennessee /\ \ \ \ / / || / (FAX)(423) 974-3509 37938-4443 USA / \ \ \ \ || cebik@utk.edu QRPARCI 2572 G-QRP 7203 CQC 125 NEQRP 347 NORCAL 1111 MIQRP 1432 NWQRP 401 ARRL Life: Educational Advisor QCWA 13211 10-10 41159 CW Ops QRP Club (VK) 476 FISTS 2600 From Cecil_A_Moore@ccm.ch.intel.com Thu Oct 31 17:38:49 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35080-50107>; Thu, 31 Oct 1996 12:38:42 -0500 Received: from marceau.fm.intel.com (marceau.fm.intel.com [132.233.247.8]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id MAA94624 for ; Thu, 31 Oct 1996 12:38:20 -0500 Received: from fmmail.fm.intel.com by marceau.fm.intel.com (8.7.6/10.0i); Thu, 31 Oct 1996 17:38:17 GMT Received: (from ccmgate@localhost) by fmmail.fm.intel.com (8.7.4/8.7.3) id JAA17653 for qrp-l@lehigh.edu; Thu, 31 Oct 1996 09:36:41 -0800 (PST) Received: by ccm.fm.intel.com (ccmgate 3.2 #2) Thu, 31 Oct 96 09:36:41 PST Date: Thu, 31 Oct 96 09:17:00 PST From: Cecil A Moore Illegal-Object: Syntax error in Message-ID: value found on fidoii.cc.lehigh.edu: Message-ID: It seems, from this rough test, that the actual polarization >is oblique, between vertical and horizontal. LB wrote: >Compared to horizontal dipoles and loops, the triangle has >a much lower angle of maximum radiation, but it also has >enough higher angle radiation for shorter path QSOs. Hi Guys, I designed this triangle to have close to equal vertical low-angle and horizontal medium-angle radiation. That would imply that it is not a good vhf/uhf antenna. It was designed for HF shortwave operation. The vertical radiation is maximum at 18 degrees take-off-angle. The horizontal radiation is maximum at 60 degrees take-off-angle. Vertical and horizontal radiation are equal at 27 degrees. I wanted an antenna that would have a big footprint. This one covers close in to far out with a horizontal beamwidth of 2x100 degrees. If one wants only low-angle radiation, good for dx, a vertical rectangular loop is a good antenna. 73, Cecil, W6RCA, OOTC (not speaking for my employer) From cebik@utkux.utcc.utk.edu Thu Oct 31 22:26:10 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35035-28857>; Thu, 31 Oct 1996 17:26:07 -0500 Received: from utkux4.utcc.utk.edu (UTKUX4.UTCC.UTK.EDU [128.169.76.11]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with SMTP id RAA192935 for ; Thu, 31 Oct 1996 17:26:04 -0500 Received: from localhost by utkux4.utcc.utk.edu with SMTP (SMI-8.6/2.7c-UTK) id WAA05470; Thu, 31 Oct 1996 22:22:00 GMT Date: Thu, 31 Oct 1996 17:21:59 -0500 (EST) From: "L. B. Cebik" X-Sender: cebik@utkux4.utcc.utk.edu To: Cecil A Moore cc: Low Power Amateur Radio Discussion Subject: Re: W6RCA Triangular Loop In-Reply-To: <96Oct31.124003est.35091-28857+56@fidoii.cc.lehigh.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Thu, 31 Oct 1996, Cecil A Moore wrote: > Hi Guys, I designed this triangle to have close to equal > vertical low-angle and horizontal medium-angle radiation. > That would imply that it is not a good vhf/uhf antenna. It was > designed for HF shortwave operation. The vertical radiation is > maximum at 18 degrees take-off-angle. The horizontal radiation > is maximum at 60 degrees take-off-angle. Vertical and > horizontal radiation are equal at 27 degrees. I wanted an > antenna that would have a big footprint. This one covers > close in to far out with a horizontal beamwidth of 2x100 degrees. Cecil, and all, The HF properties of an antenna that is up only a fraction of a wavelength would only be transferrable to a VHF/UHF antenna up the same fraction of a wavelength. Above about 2 wavelengths (about 12-13' at 2 meters) the antenna approximates its free space properties, with an elevation pattern that shows a low angle of maximum radiation, whether horizontal or vertical. Virtually all the antennas I have transferred from HF to VHF at 30' above ground have an angle of max radiation of about 3 degrees, with aximuth patterns close to free space patterns, but with additional gain due to ground reflections. Hence, the triangle had a gain of about 8.0 dBi at 2 meters and 30' up, while the half square is about another dB up. Although the polarization of the antenna's fields is important in point-to-point communications common on VHF and UHF, the individual polarized fields and their T-O angles are less important than the overall or total far field at HF, where ionospheric refraction tends to scramble polarization. The evidence of unscambled polarization for skip communications suggests that it is far rarer than scrambled. The models I ran showed your main lobe at 20 degrees and a higher angle bulge in the 50-60 degree region, but the depression between the two was really quite minor. Hence, a user can expect relatively continuous coverage within about 3-4 dB from about 15 to 60 degrees, which is sort what I think you were aiming for. By way of contrast, the half square has a much lower level upper angle lobe, down by more than 10 dB relative to the main low level lobe--distinctly oriented to the long haul at the expense of the short haul. Of course, this holds true only if we assume 40 meters to be stable enough to make a test for the duration of a standard QSO, but the difference is likely to hold up statistically over a few months of operating. Actually, the idea of using your triangle at 2 meters has another appeal. I can see someone using one as a combination antenna and frame for a club banner on field day and other events when 2-meter communications is handy and publicity is also useful. Now if I only had a couple of big trees on my once-upon-a-time farm acre to support your triangle, I'd have one up for 30 meters. -73- LB, W4RNL From kjlopez@earthlink.net Fri Nov 1 01:33:19 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35132-50107>; Thu, 31 Oct 1996 20:33:01 -0500 Received: from norway.it.earthlink.net (norway-c.it.earthlink.net [204.119.177.49]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id UAA179959 for ; Thu, 31 Oct 1996 20:32:10 -0500 Received: from 206.250.111.13 (max5-so-ca-12.earthlink.net [206.250.111.13]) by norway.it.earthlink.net (8.7.5/8.7.3) with SMTP id RAA19872; Thu, 31 Oct 1996 17:27:38 -0800 (PST) Message-ID: <3279526B.168F@earthlink.net> Date: Thu, 31 Oct 1996 17:29:15 -0800 From: Ken Lopez Reply-To: kjlopez@earthlink.net X-Mailer: Mozilla 2.0 (Macintosh; U; 68K) MIME-Version: 1.0 To: Cecil_A_Moore@ccm.ch.intel.com CC: Low Power Amateur Radio Discussion Subject: Re: W6RCA Triangular Loop References: <96Oct31.123949est.35089-28857+55@fidoii.cc.lehigh.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Greetings, I have been following your discussion with interest, as this might be a good solution at my new QTH. Does this antenna work on any of the higher bands? Any experience that you might relate would be helpful. 73, Ken, N6TZV, Subject: Re: W6RCA Triangular Loop To: Ken Lopez cc: Low Power Amateur Radio Discussion In-Reply-To: <3279526B.168F@earthlink.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Ken, a triangular loop is generally referred to as a Delta Loop antenna. There is a good article on it in the Antenna Handbook (ARRL). It will work on higher bands as well. The formula for calculating the length of the antenna is 1005 dvided by the frequency in Mhz. 1005 div by 3.651 Mhz will yield the length. Divide it by three if you want a simetrical antenna with equal lengths on three sides of the Delta Loop. Feeding it at the top of the antenna gives it horizontal polarization and at the bottom gives it vertical polorization (depending on where you connect the feed line. Just enough info to maybe confuse you. Good luck and 73 de Kevin WV5Z Kevin Bunin p014455b@pbfreenet.seflin.lib.fl.us From cebik@utkux.utcc.utk.edu Fri Nov 1 13:17:32 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35082-49886>; Fri, 1 Nov 1996 08:17:21 -0500 Received: from utkux4.utcc.utk.edu (UTKUX4.UTCC.UTK.EDU [128.169.76.11]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with SMTP id IAA272998 for ; Fri, 1 Nov 1996 08:17:01 -0500 Received: from localhost by utkux4.utcc.utk.edu with SMTP (SMI-8.6/2.7c-UTK) id NAA14254; Fri, 1 Nov 1996 13:16:04 GMT Date: Fri, 1 Nov 1996 08:16:04 -0500 (EST) From: "L. B. Cebik" X-Sender: cebik@utkux4.utcc.utk.edu To: Kevin Bunin cc: Low Power Amateur Radio Discussion Subject: Re: W6RCA Triangular Loop In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Thu, 31 Oct 1996, Kevin Bunin wrote: > Ken, a triangular loop is generally referred to as a Delta Loop antenna. > There is a good article on it in the Antenna Handbook (ARRL). Unfortunately, most of what was said taken from the ARRL book will not work out. The W6RCA triangle, which he has presented on this net, is a closed triangular loop, but not a strict delta, since a strict delta should have equal angle going up or down from a horizontal wire. Cecil's antenna was designed to get a good combination of horizontal and vertical radiation to combine in a pattern that fits the long and short skip operations he favors. A delat loop can use many angles, but the equilateral and right angle designs are most common. The equilateral design can be fed almost anywhere with about 150 ohms impedance. If fed about 25% up one angular leg, it gives a pattern dominated by vertical polarization (without need for counterpoises or radials, since it is balanced and the horizontal wire plus the 25% up each leg to the feedpoint and it corresponding point across the way constitute a phasing line. The right angle delta goes from the equilateral's 60 degree apex to a 90 degree apex and shows a variable impedance as you move the feedpoint around. However, when fed about 10-15% up one sloping leg, it shows 50 ohms and the pattern is even more vertically polarized than the equilateral--and a wee bit stronger. Both have very low radiation angles and not much high angle radiation, and are favored by those principally interested in DX. Fed elsewhere around the perimeter, the vertically-mounted deltas show predominatly horizontally polarized radiation. The take-off angle increases as horizontally polarized radiation dominates the pattern. Using the old, relatively inaccurate quad/delta formula (1005/f) is not likely to be accurate, but it may be a starting point. The loop dimensions will vary with height (a little), ground clutter (a little to a lot), wire size, and amount and type of wire insulation. Difference may cancel or add, depending on your yard. Erected horizontally (with all three corners about the same height above ground), the antenna becomes a horizontally polarized 3-cormered loop with a high radiation angle. See ON4UN's Low Band DXing book (ARRL) and previous discussions by W6RCA and others for further details on the patterns and performance of the various forms of triangular antennas erected in a vertical plane. -73- LB, W4RNL From kjlopez@earthlink.net Fri Nov 1 16:17:38 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35287-49886>; Fri, 1 Nov 1996 11:17:30 -0500 Received: from cyprus.it.earthlink.net (cyprus-c.it.earthlink.net [204.119.177.65]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id LAA72316 for ; Fri, 1 Nov 1996 11:17:25 -0500 Received: from 206.250.111.25 (max5-so-ca-24.earthlink.net [206.250.111.25]) by cyprus.it.earthlink.net (8.7.5/8.7.3) with SMTP id IAA06938; Fri, 1 Nov 1996 08:17:13 -0800 (PST) Message-ID: <327A22BD.5411@earthlink.net> Date: Fri, 01 Nov 1996 08:18:05 -0800 From: Ken Lopez Reply-To: kjlopez@earthlink.net X-Mailer: Mozilla 2.0 (Macintosh; U; 68K) MIME-Version: 1.0 To: Kevin Bunin CC: Low Power Amateur Radio Discussion Subject: Re: W6RCA Triangular Loop References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Kevin, Thanks for the reply. I guess I should have phrased my question more carefully. I am aware of the various loops, although I have had no practical experience with them. I was interested in the operational characteristics of this particular one in terms of pattern on the higher frequencies, and whether or not open wire feeders would be preferable to coax, etc. I am trying to solve the problem of a smaller lot at the new QTH and am assessing the relative merits of the various antennas. Actually I have been looking closely at the vertical loop, and the halfsquare, so the recent post comparing it with the triangular loop and its pattern was most informative. I was wondering how the triangular loop pattern changed with frequency, as the half square is essentially a one band antenna in this regard. 73, Ken N6TZV From Cecil_A_Moore@ccm.ch.intel.com Tue Nov 5 02:23:00 1996 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35101-30463>; Mon, 4 Nov 1996 21:22:55 -0500 Received: from marceau.fm.intel.com (marceau.fm.intel.com [132.233.247.8]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with ESMTP id VAA133456 for ; Mon, 4 Nov 1996 21:22:44 -0500 Received: from fmmail.fm.intel.com by marceau.fm.intel.com (8.7.6/10.0i); Tue, 5 Nov 1996 02:22:43 GMT Received: (from ccmgate@localhost) by fmmail.fm.intel.com (8.7.4/8.7.3) id SAA13584 for qrp-l@lehigh.edu; Mon, 4 Nov 1996 18:21:01 -0800 (PST) Received: by ccm.fm.intel.com (ccmgate 3.2 #2) Mon, 04 Nov 96 18:21:01 PST Date: Mon, 04 Nov 96 18:05:00 PST From: Cecil A Moore Illegal-Object: Syntax error in Message-ID: value found on fidoii.cc.lehigh.edu: Message-ID: I have been following your discussion with interest, as this might be >a good solution at my new QTH. Does this antenna work on any of the >higher bands? 73, Ken, N6TZV Hi Ken, Here's what EZNEC sez: band gain TOA 50ohmSWR 450ohmSWR 30m 3.6 59 high 36 20m 6.5 28 4.7 3.5 17m 7.7 22 high 9.5 15m 8.8 19 4 2.2 12m 9.3 16 high 5.7 10m 9.8 14 6 1.8 Assuming one is feeding the triangle at the low point on the south side of the triangle (that's what I'm doing), the antenna has a beam effect in the two northern lobes of the cloverleaf pattern. So the above numbers are for two lobes pointed approximately NE and NW and getting more northerly as frequency increases. As one can see, this is a good multiband antenna when fed with coax on 40m and using a tuner on 20m, 15m, and 10m. It should work well fed with 450 ohm ladderline all the way from 40m-10m. It can be used on 80m by breaking the loop halfway around from the feedpoint and feeding it with ladderline although the resistance is pretty low and the reactance pretty high on 80m. In short, if you are going to use this antenna on any band that is not an integer multiple of 40m, feed it with ladderline. 73, Cecil, W6RCA, OOTC (not speaking for my employer)