Cebik Loop Antenna

I think the limit is a 15M that can be handle pretty well specially if in the 2 el configuration. 01 This note looks at the antenna and antenna model for the 40 meter Moxon Yagi designed by Dave Leeson, W6NL. I have collected the questions and boiled them down to 10, all of which have many variations. Perhaps too many new hams embarking on their first HF adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceiver's output connector. Delta Loop Feed Model Comparisons. CEBIK : THE HAM antenna site: Antenna-street. 98 KB Want a Good Microwave Antenna-Drink More Coffee. As another EZNEC exercise, hang a 6-foot wire (representing the coax shield) at a current null point in your favorite quad DE and watch the pattern change. Cebik, W4RNL. I have AIMuhf vector impedance analyzer that is a great tool to measure the complex impedance, SWR and other antenna parameters quickly. This fact will be very important whe optimizing a NVIS antenna to work over a wide range of frequencies. New Website for Magnetic Loop. It has a SWR bridge built in and checks the swr as it tunes to resonance. The "Three Element Parasitic Loop 4X Array": one driven 4x loop, one reflector 4x loop and one director 4x loop. The antenna will be guyed with 3 lines of #36 nylon ’ line. W1GHZ Microwave Antenna Book Online. MoxGen will show you the dimensions and (optionally) generate an antenna model file for a 50 ohm Moxon Rectangle antenna, given the design frequency and wire size. ıEMCOM is a big part of amateur radio. 1985 Top Loaded Delta Loop Revisited - K1YZW, Walter Schreuer QST Hinks and Kinks June 1998 Power and Antenna Gain on 60 Meters - W4RNL L. Here he and Bob Cerreto provide the details on how to build and use two versions of an update to the Big Wheel antenna from the '60s. In the first couple hours of having it up I was able to hear stations I could not hear before. The first edition appeared in 1994, with a second in 1996. Most wire antennas are an option and are inexpensive, but you will need trees to run a dipole or loop. Although this design has been around for a long time, it is only gaining popularity now due to the recent improvement in high power antenna tuners. Extended Double Zepp Antenna L. For more information on 160/80 meter backyard antennas, check out antenna articles from the late L. Book: From Transmitter to Antenna. net is dedicated to the sole purpose of furthering the abilities and interest of the Amateur Radio Community. The Half Square antenna is a great wire antenna for the DX edge. In the present paper, the authors propose BQHA antennas combined with a parasitic loop which enables one to control radiation patterns of BQHA antennas easily. Although I've not modeled my particular arrangement, the TOA seems to be very good in spite of the bottom corners of the antenna being only 20 or so feet off the ground. for over 40 years. I like loops too, but in the vertical plane in my case, suspended between 2 tall trees. Delta Loop Antennas1 I am indebted to W4RNL for a large amount of information on Delta Loops. Remember, contacts can be made using a wet string in a stiff breeze on a good day. Each side is ~ 14 M with the ver­tex of the anten­na about 7 M high­er than the base. I'm amazed at how a "shorted-out antenna" can even work at all more or less so well! My favorite vertical loop for portable and fixed use is described below. Carr, Universal Radio Research Small loop antennas have an overall wire length < 0. Tripod for the Portable HF Antenna. Rod's BIG 10-m antenna: Fractal Loop Antenna Explained Plus link to the "Web Archive" to find the antenna this page is based on that has since been taken off of the Fractal Antenna Systems webpage: Fractal Loop Explained "Archived" "Fractenna" article: L. Another useful article is from QST June 2000, Having a Field Day with the Moxon Rectangle, by L. 6 Meter Quad Turnstile Antenna. Antennas 101 Presented by: Eric Webner K4FAN Dave Tyndell KK4LY K4KL Optibeam. My Loop Antenna November 20, 2013 14 Receive Properties of Electrically-Small Loops •Loop antenna is tuned to a resonance on receive by adjusting the tuning capacitor •Atmospheric noise dominates over receiver noise at HF •Tuning is narrowband, tending to limit received noise •Gain of a loop may be lower than that of other antennas, but. First Name. Antenna Design Sites. Prototype # 1 was a "Dual Band" (40 -20 Meter) Parallel Dipole Antenna, each Dipole is a "Cage Dipole" SWR was BELOW 2. Dave Hachadorian, K6LL [email protected] Cebik’s computer modeling shows that the elongated loop HENTENNA has an edge over a regular square one wavelength loop and the regular elongated loop. As a result, we can place the stubs close to the feedpoint of the antenna, as shown in the tilted-image sketch in Fig. An especially good discussion of simple antennas is available on the excellent website of L. While ON4UNs Low Band DXing and the ARRL Antenna Books are very fine resources, any serious antenna project needs to begin with Cebik's works which are available free of charge at the CEBIK. I have at least 2 antennas per band. NOTICE: always refresh your browser for each page on this site. 9 KB: Anatomy Of A Repeater: 1. Grounded Loop webpage by OK1DQT. It has a SWR bridge built in and checks the swr as it tunes to resonance. This antenna has served me well and the design has been replicated many times by other operators who report similar results. Cebik, W4RNL. For more Amateur Radio news and information, please visit these sites:. 80 meter loop frequency plot The table above makes it fairly easy to choose the feedpoint impedance for the 80 meter loop antenna. Softening the Tubing 4. Antique Radios: Puget Sound Antique Radio Association (PSARA). HENTENNAS for receiving FM broadcast signals are very easy to build, using a wooden or PVC pipe frame and copper wire. 5 MB: Antenna Theory and Design - Wang Junjun: 7. If you have no particular preference within a given ham radio band, then simply enter its center frequency (i. Some alternative 160 meter antennas worth trying include the 3/8 wave length inverted L, a "long" random length wire, and a 3/8 wavelength loop. Cebik, W4RNL Loop antennas, down to a size around 0. 25 mt antenna UHF decoupling stub RG174A coaxial cable SO-239 connector. Despite all the words and diagrams in handbooks over the years, newcomers still send me questions about the antenna. up-solid down-solid. antenna had to say about impedance and SWR. A multi-band HF loop antenna. LB Cebik modelled a version of the VK2ABQ 2-element array built with RG58 cable and found that the perimeter of the antenna was only reduced to 80% of the full-size version - not the 67% which might have been anticipated - simply because the end spacing had to be increased in order to preserve the antenna's performance. Antec UT-1 Manual courtesy W3HD; Inside view. 02 KB Web Pages on Packet Radio. com – Website of L. Gain: The cubical quad beam antenna offers about 2 dB over a Yagi of a similar length. No wonder then that LB Cebik, W4RNL picked the doublet as one of his top five multi-band backyard antennas [Cebik, 2009]. Practical Loop Antenna Construction Design. 6m 4-Element Quad, KG4JJH Page 1 of 5 6m 4-Element Quad Antenna Build this portable short boom beam with over 8 dBd gain. As we told previously, real gain values of some commercial antennas are available on various websites like DM2BLE, and technical design notes on L. The radio must have an integreated antenna, so no antenna connector, bummer 🙂 In that case, there is no easy method of using a larger antenna to increase your range. Cebik wrote several articles on elevated radials--studies that may help you to build an efficient vertical antenna where ground losses are high. Cebik, W4RNL 1434 High Mesa Drive Knoxville, TN 37938-4443 [email protected] Here we have collected some links to building instructions for 11m antennas on the Internet. Antenna Models H-POL—The reso-nant frequency is 50. , of the wire, not of the overall loop). I live in an HOA-controlled area and they have strict rules about outdoor antennas. Hanson, KJ5VW Austin, Texas Imitation, it is said, is the sincerest form of flattery so let me beginby pointing to the direct source of my inspiration for building this antenna. Modeled with NEC-based sw, very high gain, low noise. Prototype # 1 was a "Dual Band" (40 -20 Meter) Parallel Dipole Antenna, each Dipole is a "Cage Dipole" SWR was BELOW 2. Antenna Design Data W4RNL L. Discussions include indoor antennas, WSJT Meteor Scatter, system optimization. This antenna is a high performance, full size, full wave, 80m loop antenna. Don't know if you've ever read much by Cebik on antennas, he was my hero, I've modelled and built and used dozens of his antennas over the years. Indeed, he subtitles his latest volume with just those words. ANTENNA MATCHING BY CEBIK W4RNL. In fact, the article that I posted previously (My five favorite backyard antennas by Cebik) describes the horizontally oriented loop as horizontally polarized (HOHP) and describes the differences in patterns due feed point placement but never mentions a change in polarity. While the impedance (of non-resonant elements) may be high, except at (odd or 3rd) harmonic frequencies, it will generally be reactive resulting in a need to retune the antenna lengths compared to a single-band dipole. I recall my days. The problem was to compare the performance of a Chameleon CHA F-Loop Antenna, a 0. 0 MB: An Easy Dual-Band VHF-UHF Antenna: 1. diplexer 2m/440. Although Cebik presents his antenna data using the new American 60 meter band, it is applicable to all. Loop and pre-matching circuit Uses a ladder line as impedance transformer The length of the ladder line is approx. VHF/UHF Dual Band J-Pole By: Ed Fong WB6IQN email: [email protected] This is not a theoretical text but the result of many experiences lived through the action of two heavy wind-storms. The CTR6-160 Auto Controller will work with any screwdriver antenna with or without counter switch/magnet switch. The loop in the coaxial cable allows the cable to run around the upper guy ring when the antenna is rotated through the rotator's full travel range of 450 degrees. Nevertheless, the loop is a good multi-band antenna easily fed with parallel transmission line and an ATU. The original article also references a separate website where drawings for the parts can be downloaded. Grounded Loop webpage by OK1DQT. UHF/VHF there are lots of choices and the X-50 should be fine. The removable "drawer" that allows band changes to be made via changing allicator clip positions on the coil. It can be constructed as a single band antenna fed with coax or a multiband antenna feed with kilowatt ladder line. Loop Antennas-- Plans for each Amateur Band Loop Antenna Forum-- Yahoo -- Needs subscribing but lots of info here Low Band Antennas-- From K3KY Mac Antenna Master Software Magnetic Loops for HF-- From W2BRI HF Magnetic Loop Antennas-- By Glenn C Sperry, KI6GD Magnetic Loops-- By Wolfgang DJ3TZ Magnetic Loop Antenna-- From HB9ABX. Cebik) has been reversed so that it is easier to compare to the chart from the Montana site. Hence, a horizontal 1-wavelength loop becomes a good NVIS antenna, as our 80-meter 2-wavelength loop would become on 160 meters. Notice the resultant wavelengths. RJELOOP3 * Analysis of receiving, multi-turn, square, loop antennas, ELF to HF. Combinazioni A,B,C e D. If you want a good signal on many bands, this is it. 5 :1 SWR, across the most useful portion of the 6 Meter. CEBIK : THE HAM antenna site: Antenna-street. Multiband Antennas ‐G5RV vs ZS6BKW According to an acknowledged expert in computer antenna design and modeling, L. Ham Radio - Antennas Thanks to some comments on my Monday post , I got thinking about collecting some thoughts on antennas. ıA portable antenna may skirt the HOA. Summer contests are a great reason to get away from it all and enjoy the pleasures of amateur radio. Antennas, to quote a friend, are one of life's eternal mysteries. Total length is 5 ½ feet which is a practical length for a ¾ inch 200 psi PVC pipe. Share This Collection. 0 MB: An Inexpensive TDR: 150. I've been a ham since 1976 and an RF (radio frequency) engineer (but not an antenna designer) since 1986, and along the way have used various antennas, both full size and smaller. Resources listed under 10 Meter Antennas category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. Since the server migration the dates appear 2011, however that''s a decade later than the creation and original publication. com which is now defunct. Here he and Bob Cerreto provide the details on how to build and use two versions of an update to the Big Wheel antenna from the ’60s. 4 GHz, I would like for it to have above 2. Alpha Delta Antenna Switch Repair and Cleaning; The Truth About Antenna Gain; Definitive up to date info on verticals and ground and radials; Best ever basic antenna guide for non technical people; Classic antenna article for beginners by W4RNL L. Cebik, W4RNL, developed an algorithm for calculating the dimensions of a Moxon Rectangle antenna. Cebik’s computer modeling shows that the elongated loop HENTENNA has an edge over a regular square one wavelength loop and the regular elongated loop. L1 = 30 uH, 35 turns of 2. Cebik, W4RNL, for the 2 meter amateur radio band. The antennex that you're referencing is for antennas, not amateur radio publications such as those by LE Cebik and others. Original articles, antenna modeling notes and extensive antenna design information from L. Cebik, W4RNL in the May 2002 QST magazine that goes into further detail about. 25-λ downward. Both are. Cebik, W4RNL S ing us with a feedpoint impedance in the 20- to 25- Ω range. The loop is made from one-wave­length of wire at the design fre­quen­cy of 7. It turned out to be an interesting gain comparison of single element 28. Help build our links library by submitting your favorite links. T2FD antenna A 20-meter-long T2FD antenna, covering the 5-30MHz band. Cebik explains the theory that causes the low end knee effect you describe. Hamcap Tutorials. This is the way I can actually know if antenna is a success. Basically, a moxon rectangle is a 50 ohm two element wire beam antenna. 4nec2 by Arie Voors Software per l'analisi e progetto delle antenne Antenna S/W analyzer/design. [1] [2] It performs reasonably well over a broad frequency range, without marked dead spots in terms of either frequency, direction, or angle of radiation above the horizon. Perhaps too many new hams embarking on their first HF adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceiver's output connector. Most of this work was done as part of an investigation into the. Cebik wrote several articles on elevated radials--studies that may help you to build an efficient vertical antenna where ground losses are high. Cebik's unusually good antenna pages. The efficiencies are low for a small. 44 feet) diameter radiator loop of DX Engineering DXE-400 MAX brand of LMR-400 coaxial cable, mounted either horizontally or vertically on a balcony railing near the center of the high rise apartment building in Figure 1. Cebik, W4RNL, SK. Most attempts to develop a horizontally. Loop Antennas and Lots more by VK5BR. Construction of the 2 metre cubical. OK ! - This is an expected theoretical result of local induction - fields affecting loop and dipole antennas. Arrow Antenna Barker & Williamson Antennas Cebik, W4RNL Butternut Comet Antennas ComTek Systems- 4 Squares Cubex Quad Antennas Cushcraft Delta X-Ray Antennas Diamond Antennas DX Engineering Force 12 GAP Antennas Gem Quad Products Glen Martin Engineering Hex Beam Hi-Q Antennas/Stealth II High Sierra Antennas Hy-Gain Antennas Isotron KE4UYP'S. Antennas: My Top Five Backyard Multi-Band Wire HF Antennas. This was first calculated by the recomended 1003/f (Ans x3). W4RNL - Top Five Backyard Multi-Band Wire HF Antennas. NOTICE: always refresh your browser for each page on this site. Enter your desired frequency (MHz) of operation (i. Here is a simple antenna calculator for two popular forms of ham radio HF wire antennas: the horizontal dipole and the inverted "V". Ham Radio - Antennas Thanks to some comments on my Monday post , I got thinking about collecting some thoughts on antennas. Cebik Field Nec Wrnl Science Crossed Antennas Introduction Antenna Page Eh Cfa Software Tem Rom 4 RatTail Antenna Booster A detachable. Alpha Delta Antenna Switch Repair and Cleaning; The Truth About Antenna Gain; Definitive up to date info on verticals and ground and radials; Best ever basic antenna guide for non technical people; Classic antenna article for beginners by W4RNL L. com which is now defunct. Characteristics. As stated above, a standard Slinky coil has 90 turns. CUSHCRAFT ASQ-6 Antenna Loop, ASQ6 - Ham Radio Outlet Experimental Omni-Directional Antennas for 6-Meters L. 44 feet) diameter radiator loop of DX Engineering DXE-400 MAX brand of LMR-400 coaxial cable, mounted either horizontally or vertically on a balcony railing near the center of the high rise apartment building in Figure 1. There more good information here than anywhere! www. Product Review / Announcement, Giovannini D2T Antenna, (Cebik, W4RNL), CQ 2000, Jun pg 40. The antenna offers modest gain and F/B with an easily matched feedpoint impedance. com W4RNL (sk) Antenna guru. In its place a 135 foot doublet is going up. Climie is a high elevation site north of the Capital city of Wellington, New Zealand. com - Website of L. Physical attributes of an antenna, in conjunction with the operating frequency, results in constructive and destructive interference patterns being set up a points distant from the antenna. Cebik, W4RNL (SK). - a loop antenna over a dipole for locally picked up noise. Indeed, many newer amateurs think of the slim jim as a unique antenna, and some have claimed extraordinary performance capabilities for it--all without a good sense of what it takes to make. Ham radio operators rarely listen to that old saying. After i do that i see in the geometry edit many wires linearly alligned. Help build our links library by submitting your favorite links. Resources listed under 10 Meter Antennas category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. Also note that the Feedpoint Gap is between the two Zig-Zag Elements, running Horizontal for Horizontally Polarized Antennas as shown here. 4nec2 Guide 4nec2 Guide. 40 Meter Parasitic Delta Loop Array Attributes: Attribute: Ranking: Comments: Simplicity: Good: There is not much to this antenna. 6m 4-Element Quad, KG4JJH Page 1 of 5 6m 4-Element Quad Antenna Build this portable short boom beam with over 8 dBd gain. Since the SORAK BALUN is designed for a 430 Ohm load it appears as if the SORAK user is not supposed to use resonate antennas, only the wide band configurations shown in the manual. And the antenna performs as a vertical omnidirectional antenna. The first idea limits us to a single antenna. The wavelength heights can be translated into any frequency where NVIS antenna performance is n. Its light weight, 6. Homebrew Fan Dipole. It is important to note that …. λ/2 at 21 MHz. By the way, contrary to a previous post, there is no need to use fine wire in a loop antenna. Cebik, W4RNL. The Novice Antenna Notebook, The Half-Wave Grounded Loop by Doug DeMaw, W1FB ARRL 1988 First Edition pg. Both antennas are heavily unbalansed with 1/4 wave tail to the source. Cebik discusses some dif-ferent options for omnidirectional horizon-tally polarized antennas. 21-page article from 2004 by L. The braid of the coax will become part of the antenna. 175 wavelength (7 meters, ~21. This month, I'll take another look at receive antennas for DTV. For an air-core medium wave or shortwave loop, 18 guage or so should be ideal. com From: "L. 160-80m Coaxial Loop Receiving Antennas 160Loop Balloon and Kite Antennas Inverted u for 160m KN4LF 160 Meter Balanced Coaxial Receiving Loop Antenna. 40 Meter Parasitic Delta Loop Array Wire Diagram Wires 1, 2, and 3 represent the driven loop element. Construction of the 2 metre cubical. "Loop Antennas", ARRL Antenna Book, 16th edition, pages 5-1 4. Browsing the ol' internet, I saw several designs for compact loops. Antennas Made of Wire Volume-3, 789 pages 18 Mb Antenna Modeling Notes - 7 Volumes including the models 16 Mb. A small loop is defined as an antenna in the shape of a loop with a conductor length (circumference) less than one-third of a wavelength. The ablity to 'rotate' a small Loop Antenna to Null-Out. It has passed through phases of love and hate, honor and denigration, use. Its light weight, 6. Type in a Radius and Spacing and press "Calculate" The characteristic impedance of the line is displayed in the last box and the blue dots under the panel show the proportions of the cable providing (Radius+Spacing) < 80. antenna projects for 10 meters band category is a curation of 77 web resources on , A 10 metre EH Antenna, The 10 Meter Loop Antenna, 10 meter DiPole. Construction of the 2 metre cubical. Cebik, W4RNL 1434 High Mesa Drive Knoxville, TN 37938-4443 [email protected] Hanson, KJ5VW Austin, Texas Imitation, it is said, is the sincerest form of flattery so let me beginby pointing to the direct source of my inspiration for building this antenna. 4nec2 by Arie Voors Software per l'analisi e progetto delle antenne Antenna S/W analyzer/design. Cebik, W4RNL, ARRL Technical Adviser and antenna authority, passed away last week of natural causes. "The Droopy Loop" by KJ7MZ, QST July 1996, page 57 3. The other side of the SO-239 is attached. com W4RNL (sk) Antenna guru. Hexbeam Design Data. 5-λ has a very high feedpoint impedance value, often so high as to. Cebik (W4RNL) (SK). The Folded Dipole is not used much amongst Radio amateurs, probably due to the fact that this antenna uses twice as much wire as a single-wire dipole. Cebik also has an interesting three-part discussion of the popular G5RV antenna, which allows use on several amateur bands, and you can see the first article by clicking here. 40 Meter Parasitic Delta Loop Array Attributes: Attribute: Ranking: Comments: Simplicity: Good: There is not much to this antenna. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] The pattern of these small loop antennas is a variant of the classic “Figure-8” pattern. As is typical of loops, there are some deep nulls. "HO-HO-HOHPLs" by W4RNL (www. com is your friend. * QST 2004 ARTICLES * December 2004 ANTENNA: Building a Medium-Gain, Wide-Band, 2 Meter Yagi 33-37 ANTENNA: Surviving in Suburbia, how I learned to love simple antenna 47-48 ANTENNA: The FARApole, protable HF ant for 6 through 20 m, for toting 52-54 ANTENNA: Spi-Ro AS-2 All-Band Antenna, Spi-Ro Antenna $65 800-728-7594 55-55 ANTENNA: The Ubiquitous PL-259 56-56 ANTENNA: The "TENNA-TUNE. Rod's BIG 10-m antenna: Fractal Loop Antenna Explained Plus link to the "Web Archive" to find the antenna this page is based on that has since been taken off of the Fractal Antenna Systems webpage: Fractal Loop Explained "Archived" "Fractenna" article: L. It should be remembered when considering its use that the quad, when fed at the bottom gives horizontal polarisation. The loop will probally be a better receiving antenna and is a good choice if you have under 50ft (length) to erect a wire. Most wire antennas are an option and are inexpensive, but you will need trees to run a dipole or loop. Speedometers, Thermometers, SWR Meters, and Smith Charts. antenna switch. com has been offline for four days or moreleading to my general query here. Cebik, W4RNL, for the 2 meter amateur radio band. Keep in mind that they are comparing different antennas (one wave length loop vs half wave dipole) but they both come to virtually the same conclusion. Cebik Antennas (full text) Full-Wave Loop Antenna Length Calculator. Chris Wright, 61, elected to go to court rather than pay a $750 fine he was given for erecting the radio apparatus without approval. Cebik, W4RNL, located here. The second idea opens the door to adapting many possible antennas to omnidirectional work. I've been a ham since 1976 and an RF (radio frequency) engineer (but not an antenna designer) since 1986, and along the way have used various antennas, both full size and smaller. Put your antenna on a car or trailer and run quick connect coax to the house. Constructing a loop that can generate sufficient signal levels, and then combining that with low-loss cable to preserve that signal all the way to the receiver, will provide superior performance to any antenna with a mast-mounted preamplifier, because the preamplifier itself will raise the noise floor, canceling some of the SNR improvement that. a (Website) letter to reps and congressmen about cell and such website. Typical tubing diameters for the 2m and 70cm bands are from 0. On 40m it is a 2 wave length open loop or Bi-Square. Antennas Made of Wire Volume-2, 616 pages 3. Antenna Pattern maximum is on two diagonals, 300-deg for High Freqs and 335-deg for Low Freqs. PCB design should be ready for Spring 08. Cebik's books on quad design are required reading. I like to combine the VHF and Field Day events with camping so my antennas need to be portable. This is a World Wide Web front end for a public domain program written by W4/VP9KF using PHP. Cebik: "Of all the G5RV antenna system cousins, the ZS6BKW antenna system has come closest to achieving the goal that is part of the G5RV mythology: a multi-band HF antenna consisting of a single wire and simple matching system to cover as many of the amateur. 2) Testing the actual performance of the antenna requires quite a lot of work. The resistor is 800 ohm because this will give a flatter and lower SWR than when using a 450 ohm resistor. 165 wavelength (13 meters, ~41 feet). In January 2008, L. When it came to simple and effective HF antennas he wasn't all that excited by large wire loops as he considered using them mostly on their fundamental frequencies where they primarily used for NVIS. Yagi in the 1920s Did not receive full acclaim in the United States until 1928. 25λ) horizontal loop (reflector could also. The other side of the SO-239 is attached. So I decided to take a systematic look at models of the T2FD. If you think this is older irrelevant information then I think you should listen to L. 5 for the FULL BAND on 20 meters. Horizontal Polarization. Arrow Antenna Barker & Williamson Antennas Cebik, W4RNL Butternut Comet Antennas ComTek Systems- 4 Squares Cubex Quad Antennas Cushcraft Delta X-Ray Antennas Diamond Antennas DX Engineering Force 12 GAP Antennas Gem Quad Products Glen Martin Engineering Hex Beam Hi-Q Antennas/Stealth II High Sierra Antennas Hy-Gain Antennas Isotron KE4UYP'S. Depending on your choice, you may prefer this reduction in size, when you're working with an antenna as large as 20m band antenna are. Cebik-Antennas An-Ten-Ten-nas: a series of articles for 10-10 News. The performance of the antenna, through the model, will be explored in several typical settings. Antenna Patterns Gain for an antenna is expressed in decibels relative to an isotropic radiator (point source that radiates equally in every direction). My favorite antenna for maximum portable efficiency is the 88' Cebik Doublet. This design now uses threaded spacers for attaching the elements to the hub, adopting an idea from Jay Hennigan. Excellent strength, made of aluminium, stainless steel and SmarTech HQ wire, for mil/aerospace uses. At a height of about λ/2, the nearby ground reflection of a horizontal HF antenna will start to be constructive at interesting take-off angles for long- distance ionospheric contacts. Have a look at this example of a very solidly built antenna built by L. Larry's Antennas LLC. Compare the setup with the Leggio and with the Cebik images. com W4RNL (sk) Antenna guru. K4TR FULL WAVE DELTA LOOP Another made to order classic antenna which is also a superb performer. LB Cebik Antennas NOTE: All who registered prior to September 14, 2012 need to re-register by clicking on red button below, right: HB9ABX : best in homebrew antennas. Many end up with a mass of wires in the back yard as they try to make separate antennas for 80, 40, 15, and 10 meters. com W4RNL (sk) Antenna guru. Cebik (SK) QST Feb 2004. The antenna is described in lengths of 89,14′ and 90′. antenna had to say about impedance and SWR. com) Do a search (Note: #1 is available to download from ARRL website, do "search" for "constructing loop antennas". This DeltaLoop let the following results: 10m: a maximum enhancement of 12 dBi at 12 degrees elevation. Wireman # 551 To antenna tuner via approx 51 ft. Loop antennas are usually quieter than long wire Antennas when receiving. 44 feet) diameter radiator loop of DX Engineering DXE-400 MAX brand of LMR-400 coaxial cable, mounted either horizontally or vertically on a balcony railing near the center of the high rise apartment building in Figure 1. The idea is based on Kazama (1993. Getting a rope high in the trees is the biggest challenge, keeping it there is the next challenge … but I find it helps immensely to (a) use a complete loop of rope over the tree so you can pull the antenna connection up AND down as necessary e. 4 KB: Analisi elettrica degli accordatori d'antenna - IW5EIK: 407. W4NRL has made detailed comparisons and calculations on several different antennas. Cebik (W4RNL) (SK). I do not claim that any of these antenna designs are original. [04/19] BE21 The Basic Guide to VHF-UHF Ham Radio $4. Horizontal HF antennas … benefit from nearby ground gain. The first step was to take the 14MHz Moxon model and run it on 18. "HO-HO-HOHPLs" by W4RNL (www. Cebik Field Nec Wrnl Science Crossed Antennas Introduction Antenna Page Eh Cfa Software Tem Rom 4 RatTail Antenna Booster A detachable. , 34601 or [email protected] Bobtail Curtain for 20 Meters: A True Story I love wire antennas, especially those at low heights. HORIZONTAL LOOP ANTENNA CONSTRUCTION. I like to combine the VHF and Field Day events with camping so my antennas need to be portable. The skywire loop is an excellent antenna - they can be a bit of work to get up in the air if you have a lot of obstacles (trees, xyl, etc. net di Cebik, di Dan Handelsman e altri an-cora. "KL7JR Sloping Vertical Delta Loop 80-6 Meters" Imagine 9 bands on one wire antenna! (Updated August 1, 2014. Apr 10, 2020 - Explore kb9umi's board "Antennas" on Pinterest. Cebik, W4RNL (SK). 102 at 20:07. The 88 footer is a simple concept, a dipole fed with open, ladder, or in this case, about 50ft. Cebik W4RNL (SK) called this category of antenna HOHPL or Horizontally oriented Horizontally Polarized Large antenna. In January 2008, L. "2 x 3 = 6" by L. Two Dollar Helical HF Portable Antenna. L1 = 30 uH, 35 turns of 2. Cebik, W4RNL 1434 High Mesa Drive Knoxville, TN 37938-4443 e-mail: [email protected] This antenna has served me well and the design has been replicated many times by other operators who report similar results. 2) Testing the actual performance of the antenna requires quite a lot of work. Attached Files:. 6m 4-Element Quad, KG4JJH Page 1 of 5 6m 4-Element Quad Antenna Build this portable short boom beam with over 8 dBd gain. Cebik, W4RNL, developed an algorithm for calculating the dimensions of a Moxon Rectangle antenna. Unfolding the 100-foot loop and making it a 100-foot doublet is an idea. How to use an. Typical tubing diameters for the 2m and 70cm bands are from 0. It is easy to experiment with them without having to climb trees, towers. This was first calculated by the recomended 1003/f (Ans x3). 175 wavelength (7 meters, ~21. Co mparing apples and peers like beams vs. This photograph is from an exhibition last year at Abstrakt Art Gallery, sponsored by Objex Design. "HO-HO-HOHPLs" av W4RNL (www. (It is the only HF antenna that I ever bought!) It is the SPI-RO Manufacturing Company's Model A-10. Cebik, W4RNL Grounded Loop webpage by G4NSJ. Loop Antennas Full-wave horizontal loop: good for short-range communications, NVIS or "cloudwarmer" antenna. Addeddate 2016-10-27 21:52:08 Coverleaf 0 Identifier Cebik-Antennas Identifier-ark ark:/13960/t5x68g63k Ocr ABBYY FineReader 11. 2m plans and instructions; small tuned VHF loop; VHF antenna in a lunchbox; 144 MHz Magnetic Loop. 1, which shows the dimensions for a do-it-yourself UHF TV rhombic antenna. [4] Moxon antennas are often used by radio amateurs in portable forms and on field days because of their lightweight construction. The choice of which member of the family to use was based on practical considerations rather than. Triangular Loop Antenna -- W6DL, Norman Watson QST Technical Correspondence April 1968 The Reduced, Full Performance, Corner Fed Delta Loop - G3TKN, Lear Ham Radio Jan. Moxon, in his HF Antennas for All Locations, provides the essential clue: "the main benefit [of a beam] accrues from the reduction of interference during reception, though the 4 to 6 dB gain provided by typical amateur beams is an important bonus and probably the reason which carries the most weight with the majority of amateurs. You may use 12- or 14-AWG instead. Forum discussion: Anyone got any plans for a real simple 20 meter loop? I have some extra wire laying around. I always ask my antenna questions over on the other site, so I figured I'd give you guys a chance to answer one. 1 at lowest point), for ALMOST the FULL BAND on 40 Meters, and under 1. Grassroots Emergency Communications Operations ©1997 - 2019 Neighborhood Link, Inc. And the antenna performs as a vertical omnidirectional antenna. They exhibit deep nulls perpendicular to the plane of the loop, and broad maxima off the ends of the loop. Here he and Bob Cerreto provide the details on how to build and use two versions of an update to the Big Wheel antenna from the ’60s. High Performance Cubical Quad Antennas 3rd Edition by John Koszeghy, K3BB: a Review. Connect coax from the radio to the feedpoint of the antenna, center conductor of the coax to the antenna wire. Hentenna mached loop antenna. Cebik, W4RNL. Share This Collection. Cebik - W4RNL. ıEMCOM is a big part of amateur radio. As we told previously, real gain values of some commercial antennas are available on various websites like DM2BLE, and technical design notes on L. Many rumors and misconceptions exist in the amateur radio world about stacking VHF/UHF antennas on the same mast. • For best results, the lengths of the 3 sides should be approximately equal • The resistive impedance is ~130 interface with 4:1 BALUN • 2:1 VSWR Bandwidth Covers whole band at 40M and up (~ 4 % of Freq). CW Transmitter on 17 meters band (18MHz) with 2N2222A transistor. Cebik's 88 foot backup doublet. One can see that the tail is heavily driven in case of the dipole and almost not driven in case of the loop. The EZNEC model predicts the antenna to have a gain of 11 dBi and front-to-back ratio of 25 dB at. Antenna Design Sites. 4nec2 by Arie Voors Software per l'analisi e progetto delle antenne Antenna S/W analyzer/design. Those with existing aluminum stock can likely reduce cost. After i do that i see in the geometry edit many wires linearly alligned. At a height of about λ/2, the nearby ground reflection of a horizontal HF antenna will start to be constructive at interesting take-off angles for long- distance ionospheric contacts. Put your antenna on a car or trailer and run quick connect coax to the house. Diplexer in a can. I used red and yellow. I like loops too, but in the vertical plane in my case, suspended between 2 tall trees. Both antennas are heavily unbalansed with 1/4 wave tail to the source. Arrl Antenna Handbook – A must-have book, you can purchase a used copy for under $20. I referred to measurements I had previously made with 10m vertical antennas fed with 4:1 Ununs. Summary • Loading changes antenna characteristics - Feed Impedance, Gain and Angle of Radiation • No reduction in the requirements for - height above earth - ground/radial systems • With expedient application of the loading the efficiency of the system can be kept high - Apply 'end' loading first - Apply inductive loading in the order of ---. Cebik - W4RNL. Cebik's papers on antennas and antenna modeling. Antennas, to quote a friend, are one of life's eternal mysteries. Cebik, W4RNL Loop antennas, down to a size around 0. The loop will never perform nearly as well as an outdoor antenna, high and clear of surrounding objects. 700 amateur radio topics - 6,000 links & 133 pages - from antennas to zones NOTE: AC6V. Matching to the feed-line is achieved by sliding the connection of the feedline back and forth along the stub until an impedance match is obtained. According to an acknowledged expert in computer antenna design and modeling, L. See also Beginner's Guide to modeling with NEC - a QST article series by L. Breaking the loop and adding a 50-ohm load at a current minimum will not affect it, but adding an unbalanced feedline certainly will. My procedure involved two steps: creating a basic design with a uniform-diameter. Dave Hachadorian, K6LL [email protected] The different bands are great for talking to amateur radio operators (hams) at different distances, different times of the day, different seasons and different times during the solar. [email protected] Have a look at this example of a very solidly built antenna built by L. How to use an. Here is a simple antenna calculator for two popular forms of ham radio HF wire antennas: the horizontal dipole and the inverted "V". Constructing a loop that can generate sufficient signal levels, and then combining that with low-loss cable to preserve that signal all the way to the receiver, will provide superior performance to any antenna with a mast-mounted preamplifier, because the preamplifier itself will raise the noise floor, canceling some of the SNR improvement that. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] The performance of these antennas has been extensively analysed by L. All readings were taken with a Array Solutions AIM-1470b Antenna Analyzer. W4RNL - Top Five Backyard Multi-Band Wire HF Antennas. Cebik and there is an interesting description of a compact size quad. Antennae for the Low Bands. A delta loop antenna project for the 40 meters band, include dimensions 80 meters band, with construction details, schematic and tuning instructions. However, raising the antenna without breaking schedule 40 may be tricky. L1 = 30 uH, 35 turns of 2. Raising and lowering a fiberglass mast is easy, and two or three long velcro strips are enough to strap the pole to a post, fence, or a medium tree trunk. The loop can be found on eBay for under US$45 with free shipping. All readings were taken with a Array Solutions AIM-1470b Antenna Analyzer. The inductance should be as. There is a specific group for builders and users of SkyWire Loop Antennas. The other is the principle of obtaining omnidirectional patterns by phasing almost any crossed antennas 90 ° out of phase. Cebik, W4RNL, ARRL Technical Adviser and antenna authority, passed away last week of natural causes. BJ is certainly interested…you can’t have too many receive antennas as K1ZM says, and right now BJ is down to one. bottom-fed wavelength rectangle, bo ttom-fed 2 element Moxon rectangle 2 element driver-reflector Yagi 3 element Yagi Mode/ file name dp160-fs q60-fs-bf eqd60-fs-bf rad60-ts-bf rect60-fs-bf. Antennas Made of Wire Volume-3, 789 pages 18 Mb Antenna Modeling Notes - 7 Volumes including the models 16 Mb. 3 wavelengths have the highest gain. Extensive design of Loop Fed Array e Optimised Wideband Array. Attach feed line and elevate the dipole in Cebik, L. 1 : 4 metre loop made from 15mm diameter copper water pipe Loop No. The pattern of these small loop antennas is a variant of the classic “Figure-8” pattern. Figure 11 - Tri band antenna with helical loop (not drawn to scale) which allows for insertion into a ¾-inch PVC pipe. com W4RNL (sk) Antenna guru. The T2FD (Tilted Terminated Folded Dipole) is a general-purpose shortwave antenna developed in the late 1940s by the United States Navy. You may use 12- or 14-AWG instead. The delta loop, though, had a matching network to put it on 17m, and I neither wanted to give up 17 nor put up a separate antenna for it, so I decided to design a matching network. How much of a compromise can be debated by the engineers. NVIS ANTENNA THEORY AND DESIGN 11 and 12 courteous of L. RJELOOP2 * Transceiving, single-turn, magloop antennas of rectangular shape. Extensive design of Loop Fed Array e Optimised Wideband Array. An ARRL Life Member, Cebik was known to many hams for the numerous articles he wrote on antennas and antenna modeling. net e-mail address that forwards to your existing e-mail account, along with free web. Cebik W4RNL in the excellent series of articles “Self-Contained Vertically Polarized Wire Antennas: A Family Album” that can be found on his website www. 5 MHz at a height of 15 feet. “2 x 3 = 6” by L. This is the way I can actually know if antenna is a success. The choice of which member of the family to use was based on practical considerations rather than. Things to notice: try frequencies 149. All the competition has to offer is unity gain at best per antenna bay and half of that on all CP models. Climie is a high elevation site north of the Capital city of Wellington, New Zealand. Matching to the feed-line is achieved by sliding the connection of the feedline back and forth along the stub until an impedance match is obtained. bottom-fed wavelength nght-angle delta loop. 40 Meter Parasitic Delta Loop Array Attributes: Attribute: Ranking: Comments: Simplicity: Good: There is not much to this antenna. 5-λ, still qualify as big loops compared to the "small" loop sizes that range from 0. Common mode currents in end fed antennas. Other sources leave the. This photograph is from an exhibition last year at Abstrakt Art Gallery, sponsored by Objex Design. antenna projects for 10 meters band category is a curation of 77 web resources on , A 10 metre EH Antenna, The 10 Meter Loop Antenna, 10 meter DiPole. Electromagnetic. com - Website of L. shortwave David Moore ([email protected] The toroids should be placed about ½ wave length from the bottom of the array. I have heard all sorts of warnings about screwing up the performance of my yagis by mounting them in a compact fashion on my rover masts. New Website for Magnetic Loop. com) wrote: ARRL says that one should use sheilded cable for a loop antenna with the sheild attached to ground and the core being used for the signal. VHF/UHF Dual Band J-Pole By: Ed Fong WB6IQN email: [email protected] 5 MB: Antenna Theory and Design - Wang Junjun: 7. See also Beginner's Guide to modeling with NEC - a QST article series by L. Figure 1—Outline sketch and dimensions of the 2-meter-plus LPDA. Larry's Antennas LLC. Vertically Oriented Multi-Band > Antennas" First three general comments not specifically about the loop: While the models are interesting, there are a few shortcomings. Connect coax from the radio to the feedpoint of the antenna, center conductor of the coax to the antenna wire. 2m plans and instructions; small tuned VHF loop; VHF antenna in a lunchbox; 144 MHz Magnetic Loop. It was a popular antenna design during the middle of the 20th century, but fell out of common use during the latter part of the century with the growing popularity of shorter wavelengths, which only required dipole antennas of 16 feet or less. 25 mt antenna UHF decoupling stub RG174A coaxial cable SO-239 connector. However, a closed loop with a circumference of about 0. to reconnect it if it breaks, and (b) use a. Cebik, W4RNL "A 902-MHz Loop Yagi Antenna" by Don Hilliard, WØPW "A Short Boom, Wideband 3 Element Yagi for 6 Meters" by L. Blog devoted to VHF/UHF Weak Signal DXing, especially as it applies to HOA/Deed Restricted sites. Different sources use different expressions for the threshold of when an antenna becomes a long-wire antenna. He developed this antenna to resolve issues caused by large coronal discharges while using a yagi beam antenna in the thin air of higher altitudes. Either configuration would be a great addition to your "antenna farm". All FM antenna sales include free tuning to your frequency. The electrical design is a classic crossed-dipole with 75-ohm phasing section. 3:1 SWR, and tests conducted with an MFJ-259B antenna ana-lyzer verified this. Cebik's 88 foot backup doublet. Ferrite Loop Antenna -- for BC band -- From Oceanstate Electronics Fiber Glass Rods and Tubes - By KQ6RH Four Square Vertical Phased Array -- From The Yankee Clipper Contest Club Flags and Pennants -- Receive antennas for limited space with good noise rejection. • Since the coupling between the ends of the MOXON elements is critical this is not usually practical for reasons that will be presented later. Prototype # 1 was a "Dual Band" (40 -20 Meter) Parallel Dipole Antenna, each Dipole is a "Cage Dipole" SWR was BELOW 2. As a result, we can place the stubs close to the feedpoint of the antenna, as shown in the tilted-image sketch in Fig. In January 2008, L. AN ALL-BAND ANTENNA. Dean Straw (Editor) , David Sumner (Foreword by) , Kurt Andress , L. The Folded Dipole is not used much amongst Radio amateurs, probably due to the fact that this antenna uses twice as much wire as a single-wire dipole. HORIZONTAL LOOP ANTENNA CONSTRUCTION. All the competition has to offer is unity gain at best per antenna bay and half of that on all CP models. 4nec2 Guide 4nec2 Guide. Although this design has been around for a long time, it is only gaining popularity now due to the recent improvement in high power antenna tuners. CUSHCRAFT ASQ-6 Antenna Loop, ASQ6 - Ham Radio Outlet Experimental Omni-Directional Antennas for 6-Meters L. RJELOOP3 * Analysis of receiving, multi-turn, square, loop antennas, ELF to HF. Cebik, W4RNL (SK). *****God News For all How To Turn Your Dull Website into Money Making Website***** 11. The antenna is described in lengths of 89,14′ and 90′. It has modest gain and can be particulary useful on 80 and 160m. OK ! - The IP2 and IP3 differences in the active antennas - are due to the amplifier design not the antenna. In exploring antenna design, I have been particularly influenced by the following: EZNEC. Wireman # 551 To antenna tuner via approx 51 ft. You may use 12- or 14-AWG instead. Cebik W4RNL (SK) called this category of antenna HOHPL or Horizontally oriented Horizontally Polarized Large antenna. Then note below that set the frequency change at 20:06. I plan to use hf-auto with an acom2000a for the mult station in contests, and as the main station inside the house with hf-auto-r other times (main shack has moved to a building away from the house). Cebik: "Of all the G5RV antenna system cousins, the ZS6BKW antenna system has come closest to achieving the goal that is part of the G5RV mythology: a multi-band HF antenna consisting of a single wire and simple matching system to cover as many of the amateur. Loop antennas are usually quieter than long wire Antennas when receiving. Across all angles and frequencies, Raw Gain ranges from -13 to +1. Antennas Direct's design team has been changing the face of antenna design. Cebik has much on his antenna site concerning this matter. Contents: This file contains basic information on antenna books of especial interest to QRP enthusiasts. I wonder what some of you are using for a good multi band antenna with the HF-auto? I was thinking of an hf ocf dipole. PERFORMANCE The United States Navy conducted extensive transmitting and receiving tests of a single T2FD antenna in the late 1940s at Long Beach, California. Τελευταία ενημέρωση σελίδας:16/06/2008. The simple active receive loop used was found on the internet (link = broken). For more information on 160/80 meter backyard antennas, check out antenna articles from the late L. And the Folded dipole doesn't do well as a multi band antenna either. I happened to mention that I was listening to him on both VFOs. In all the configurations the near end of the antenna is connected to the radio using a BALUN and the far ends of the antenna wire(s) are terminated. Type in a Radius and Spacing and press "Calculate" The characteristic impedance of the line is displayed in the last box and the blue dots under the panel show the proportions of the cable providing (Radius+Spacing) < 80. These 10-40M, 10-80M or 10-160M dipoles are ready to be erected right after un-boxing. 5 for the FULL BAND on 20 meters. LB Cebik Antennas NOTE: All who registered prior to September 14, 2012 need to re-register by clicking on red button below, right: HB9ABX : best in homebrew antennas. What appears to have the size and shape of a 12 meter two - element beam -but isn't? What appears to have the wiring scheme of a ZL -Special -but isn't? The answer is the D2T, an innovative antenna from Giovannini Elettromeccanica of Italy. 8 and 468 with 95% end effect factor. All of the following were contained in a discussion forum on the QRP-L reflector, and were submitted by W4RNL (L. Antenna gain is measured in either dBi or dBd. SKYWIRE LOOP ANTENNA : This type of Large and Low Loop Antenna is generally called a SkyWire Loop Antenna. Cebik (W4RNL) has written extensively on the 88 foot and 44 foot dipole antennas (see The "Ideal" Back-Up Antenna for 80-20 Meters). Despite all the words and diagrams in handbooks over the years, newcomers still send me questions about the antenna. RF signals are electromagnetic waves that consist of an electric. These lengths lend themselves well to multiple band usage when used with a low loss (as. I got at a hamfest a while back. The first edition appeared in 1994, with a second in 1996. DATE REVIEWED DATE ADDED. So my offering to FDIM 9 will also be a matter of 5: my personal selection of the top 5 HF wire antennas for the backyard and for multi-band operation. If you wish to improve the gain of your loop antenna, consider adding a second turn to the main loop. For an excellent and comprehensive description of the turnstile antenna go to www. Obtained from simulations. 4 GHz, I would like for it to have above 2. Both are. of #16 "silky" stranded wire cut to one wavelength long on. The resistor is 800 ohm because this will give a flatter and lower SWR than when using a 450 ohm resistor. net Abstract A coaxial-cable trap dipole antenna installed in the attic provides a surprisingly effective solution to HF operation on the 10, 15, 20, 30, 40, and 80 meter amateur bands at a QTH with restrictive covenants that prohibit outside antennas. I have AIMuhf vector impedance analyzer that is a great tool to measure the complex impedance, SWR and other antenna parameters quickly. Ham Radio - Antennas Thanks to some comments on my Monday post , I got thinking about collecting some thoughts on antennas. For the first 4 seconds I used the loop antenna. Physical attributes of an antenna, in conjunction with the operating frequency, results in constructive and destructive interference patterns being set up a points distant from the antenna. He is a past master at creating effective portable antennas for little or no cost. This same antenna could be used for satellite or space communications as well with the addition of an appropriate reflector. 40 Meter Parasitic Delta Loop Array Attributes: Attribute: Ranking: Comments: Simplicity: Good: There is not much to this antenna. Cebik (W4RNL) or the "W6SAI HF Antenna Book" by William Orr (W6SAI). L1 = 30 uH, 35 turns of 2. Things to notice: try frequencies 149. Cebik) has been reversed so that it is easier to compare to the chart from the Montana site. 98 KB Want a Good Microwave Antenna-Drink More Coffee. The smaller, coupled loop seen on some small loop designs is there to provide impedance matching. antenna switch. A phasing harness is basically (2) sections of 75-ohm cable cut to odd quarter wavelengths X velocity factor, transitioning to a 50-ohm cable, which is usually the transmission line. Amateur radio has 10 HF (shortwave) bands, from 1. Physical attributes of an antenna, in conjunction with the operating frequency, results in constructive and destructive interference patterns being set up a points distant from the antenna. Antenna models reported by Jack Swinden W5JCK (and based on work of L. 165 wavelength (13 meters, ~41 feet). Compare the setup with the Leggio and with the Cebik images. Note that the outer tips of a Bi-Quad connect to each other. Cebik, W4RNL, ARRL Technical Adviser and antenna authority, passed away last week of natural causes. They exhibit deep nulls perpendicular to the plane of the loop, and broad maxima off the ends of the loop. VIEWS TITLE DATE ARCHIVED DATE PUBLISHED DATE REVIEWED DATE ADDED CREATOR. 8 and 468 with 95% end effect factor. The first edition appeared in 1994, with a second in 1996. An ARRL Life Member, Cebik was known to many hams for the numerous articles he wrote on antennas and antenna modeling. This study in four parts now presents NEC models that compare the expected performance of the halo, turnstile, eggbeater and Big Wheel antennas. 33ft Verticals and 4:1 Ununs Following a discussion on eham relating to the use of 4:1 Unun's for multiband operation in conjunction with 33ft vertical antennas. Of course, be sure to leave some sag when hanging up wire antennas.