Some designs connect one end of the secondary coil to the antenna socket, which then makes the coax shield act like a counterpoise. It is a resonant Half wave low on 80m (3. With my 80m EFHW wire cut for lowest SWR when plugged into the 1:64 jack I get a perfect match on 40m (end fed full wave in this case) when plugging it in for a 1:25 transformation - however the antenna is wildly zig-zagging in close proximity to the building, part of it is even in the attic, so other setups may return different results. A second length of feedline runs from there to the shack. 20-30 feet but NOT resonant. Lengthen or shorten by 1/4 wave and the tuner will handle it fine. I instead made two antennas: one center-fed and one end-fed. Length is equal to 1/2 of the wavelength for the frequency of operation. com), a model by VE3KL and the spherical geometry technique used for the Bent Dipoles "Elevated Radials" study. 75 amperes flowing to earth through station equipment, and perhaps eventually the operator (RF burns). Obviously, an EFHW antenna has a "half-wave" length only at one specific frequency. Increasing the distance between spirals increases the antenna's resonant frequency. The RadioWavz EFH antennas are a perfect match for SWL listening, and can even be used for transmitting up to 25W AM and 200W PEP/CW for Amateur Radios. Zak W1VT ARRL Senior Lab Engineer: May 3rd 2018. 5 square MM pure copper multi-strand line (UV-resistant all-weather outdoor long-term erection), antenna The total length is about 20 meters. Armed with technology it was time to revisit this "no-tune" portable antenna. The fibre masts are just tall enough to hold a 5/8 vertical for 20m, the idea of building a 5/8 was born. Part 2 - A 40 Meter EFHW with a "Radiator" wire and various length "Coax-as-Counterpoise" wires is analyzed - We will see that the common-mode current is almost always LARGER on the coax shield some distance away from the feedpoint, which is why the "counterpoise" radiates and is called "the other half of the antenna". I am a particular fan of terminated antennas- the folded dipoles- and in this case, a terminated long wire. Whether you`re QRPbackpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: mfj efhw antennas. 3:1) on 80m and 40m, and below 3:1 on 20, 15 and 10m. And I'm going to keep this VERY simple. MEF-330-1K Multi Band End Fed Half Wave Antenna Transformer. An end fed half wave antenna is one of a specific length depending on the frequency that it…. End-fed antennas at an affordable price. Do not install Section A. A few more comments about this 49:1 autotransformer EFHW design. 5 TPI to make tapping easier and to keep the losses down, 11 turns were sufficient. Dipoles need to be half a wavelength long, locating these long antennas can be an issue, especially when we are aiming for the 80 metre band or lower. An end fed half wave antenna is one of a specific length depending on the frequency that it is to be used on, for example, an end fed half wave antenna for 80 meters is about 130′ long. I am using a QRPGuys EFHW Mini-Tuner with my FT-817. As a consequence, this study proposes a simple method to easily determine the radiation pattern properties of an L-shaped wire antenna, by just knowing the ratio between the length associated to the horizontal arm (hereafter L x)andtheheight. Long wire antenna for portable operations. I instead made two antennas: one center-fed and one end-fed. These antennas can be mounted horizontally, vertically or as a sloper. MFJ-1982HP EndFed 1/2 Wave 800W 80M-10M Wire Antenna 132 feet. 00 Ex Tax: £30. FULL HF Coverage, no tuner needed on most frequencies. These End fed antennas are unique, as they are resonant on 8 bands and DO NOT require a tuner to operate. MFJ MFJ-1982MP 300 Watts Restricted space, 80-10 Meters End-Fed Half-wave. 65 – Inverted-V Beam Antenna for 30m. But don't be misled - just because they are easy to make doesn't mean they don't work well. I did not have any grounding (our counter-poise) at the feed-point nor did I have any current balun or RF choke anywhere in the feed-line. Can be set up with a single telescopic pole or support. Several weeks ago, Doug Hendricks from QRPGuys handed me a prototype kit to try. AA5TB – The End Fed Half Wave Antenna Oct 1 2014. to ensure great performance in a wide range of operating conditions. R895,00 IN STOCK. 40 results for end fed antenna Save end fed antenna to get e-mail alerts and updates on your eBay Feed. 75 amperes flowing to earth through station equipment, and perhaps eventually the operator (RF burns). Can be set up with a single telescopic pole or support. I added a 1:1 choke at the end of the feed line running from the feed point to the ground. 13m for the coax and 3. NOTE 1: This original N2CX article was first published in the 72 newsletter back in 1997 or 1998. As typically installed, it is a compromise antenna but great for portable use because it is easy to pack and easy to install. Jun 18, 2018 - The finished End Fed Half Wave antenna coupler. Another popular portable-use antenna is the random length wire and tuner combination. 5kΩ to 3kΩ. Antenna Theory - Full-Wave Dipole - If the length of the dipole, i. I did not have any grounding (our counter-poise) at the feed-point nor did I have any current balun or RF choke anywhere in the feed-line. This matcher is designed for feeding the high impedance of end-fed half wave wires, so the length of wire is determined by the operating band and needs to be cut for a half wavelength on that band. In a perfect world I would have one dipole wire for the 30m test with two feed positions. Total Length 39 Feet (12Meters) 2) GEK EFHW- 8010A (200w) 80-40-20-15-10m. A dipole is basically a length of conductor (wire) split into two portions and signal is taken off at the split. Experience has shown that most external tuners and many internal tuners will tune 80-6 meters with an antenna length of 22' to 30'. 5 turn per 25mm) Number of turns depends on the length of the antenna. Building an End-Fed, Half-Wave Antenna I’ve always been interested in end-fed, half-wave antennas before, but until this recently, I’d never built one. The original design has a 27/3 turn ratio ( 1: 81 ) on a small 43. If the dipole impedance is to be resistive, the dipole must be shortened as its diameter is increased, owing to end effect. They are more prone for problems near noise sources or consumer gear, and can easily exceed FCC RF exposure limits with surprising low power levels. Dipoles need to be half a wavelength long, locating these long antennas can be an issue, especially when we are aiming for the 80 metre band or lower. Power rating is 60W, weight is 490g. End-fed antennas at an affordable price. Even with the small pattern error, we now have a very significant. Experience has shown that most external tuners and many internal tuners will tune 80–6 meters with an antenna length of 22’ to 30’. 15m/ 2x ~23ft. 30 Watts QRP, 80-10 Meters. The only downside to EFHW antennas is the need to cut a different wire for each band. 13 dBi (which equals 0. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. Hi chaps! I am soon to attempt to build a 20m EFHW antenna similar to that described by G0KYA in his blog. But shortened to 2/3 the length, the height is now only 3 ft taller (46 ft. For best efficiency it is fitted with a 16. This tuner is intended to match to match end-fed half-wave vertical and inverted-L antenna wires to low impedance coax lines. The 20m EARCHI matchbox is an L-C matching network designed to reduce the high impedance of a 33-34. 25 shows the proper length of a dipole which is a continuous cylinder, as a function of its diameter in electrical degrees for the case where the resistance is maximum and reactance is zero at one end. If it isn't end-fed, then it's usually near-center fed and becomes a dipole antenna instead. Fed by coaxial cable. 5MHz) therefore also resonant on second, third and fourth harmonics etc. This antenna may be built as a 20 meter, 17 meter, 15 meter, 12 meter or 10 meter monoband vertical antenna. Whether you're QRP backpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $49. PackTennas are light weight, compact, portable HF antenna systems ideal for operating on the trail, at the campsite, on Field Day, SOTA activation, air travel, or HOA restricted locations. A few more comments about this 49:1 autotransformer EFHW design. This choke was made with #14 house wire and has a bit of an impedance mismatch so the antenna tuner is needed. Problems With End Fed Half Wave Antennas •#1 Problem: Common mode currents on feedline •RF in shack •High noise levels on receive •Feedline and grounding can affect SWR and tuning •Isolating the feedling from the antenna can be difficult, even with a common mode choke •High voltages, even at low power •FCC RF exposure limits can be exceeded at low power levels. If a longer antenna is desired, the provided antenna can be lengthened. And I'm going to keep this VERY simple. This is the length of wire right from the tuner terminal to the insulator at the far end. Often random wire antennas are also (inaccurately) referred to as long-wire antenna. The drawings illustrate the set up, I hope. 5:1 • No Tuner needed • Bandwidth: Over 750 kHz. With EFHW antennas using an adjustable matchbox there is a great willingness to use the tuning of the matchbox to "fix" a detuned wire or a wrong length wire. He loved working 20 meters, but the housing community he moved into prohibited antennas that could be seen by the public. With EFHW antennas using an adjustable matchbox there is a great willingness to use the tuning of the matchbox to “fix” a detuned wire or a wrong length wire. End fed half wave antenna length As the name indicates the EFHW antenna is half a wavelength long on the lowest band of operation. Length can be adjusted by looping free end over to shorten. It will present its parameters, so anybody with basic home-brew skills will be able to build it. The 50' to 100' lengths are made with DA340 cable to minimize signal loss. A simple dipole antenna can be used for improved FM broadcast signals. Over the last two weeks I have been putting together a ground counterpoise system to go along with my random length antenna (see original post). The purpose of this group is to explore the use of an end fed half wave antenna. This was stretched out across the yard and supported by some shrubby about 4 to 5 feet off the ground. If the transformer is used with an external tuner in conjunction with a single wire antenna typically 130-135 feet in length, power should be reduced on those bands that show an SWR above 1. Remember, the 9:1 balun is doing a conversion of impedance from about 450-700 ohms down to 50 ohms. 2(a): You can see that when erected in a straight line the dipole is quite directional. This choke was made with #14 house wire and has a bit of an impedance mismatch so the antenna tuner is needed. In a perfect world I would have one dipole wire for the 30m test with two feed positions. Mechanically is an end fed but electrically will operate as a full half wave on your desired operating band. Welcome to RadioWavZ Antenna Company • Home of the worlds first 160-6 Meter Hexbeam. A short length of 20mm OD PVC electrical conduit was used for the coil former. I don't think I've ever been so lucky! I quickly acquired a tape measure from the local hardware shop. See this link for more info. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. Unun 1:64 - 1-49 Variable For End Fed Half-Wave (EFHW) antenna 100+W. The Shark Fin configuration holds some promise for a 40-10m portable antenna for the following reasons. The Slim Jim can be a great portable 'roll up' antenna, if made out of 300Ω or 450Ω ladder line / twin feeder. Do not install Section A. Turning the EFHW into a four-band antenna 7. Notice how the feedpoint is not quite as high impedance as the top of the antenna. 0 MHz rated at 2 KW (SSB) The DXTREME models are the ultimate end-fed antennas with the capability of covering from 160-6 Meters and able to handle legal limit power handling with ease. The trick now is to find a length which is close to an odd multiple of ¼ wavelength on all bands of interest. The example given was for a Bluetooth antenna with a frequency of 2450MHz. Hams in general, and QRP'ers in particular, are always on a quest to find the "ultimate" antenna. It is a resonant Half wave low on 80m (3. Reading between the lines I am making a guess that your EFHW antenna is from Myantennas. Length of counterpoise should be approx. Details about K4EDF 7MHZ 14MHZ 21MHZ 28MHZ 5-35MHZ End Fed Half-Wave EFHW antenna 100W HAM. The frequency is 315MHz and I calculated that my antenna should have a length of 23,81cm for everything to be right. I have two EFHW antennas. Specifications: • Full band coverage on 20 or 17 or 15 or 12 or 10 meters with SWR under 1. Simply hang the far end from a. Time Owned: 0 to 3 months. A great portable antenna that I will use often at Montrose Harbor along the. The antenna length is 31. 0 dBd or zero gain). They are more prone for problems near noise sources or consumer gear, and can easily exceed FCC RF exposure limits with surprising low power levels. Com W0QH 2018-12-26T15:58:23-06:00. The first relies on the fact that from the end of the antenna a length of wire on or two half-waves long looks very similar. 8 metres long. QRP portable qrp skcc contest portable qrp antenna cw DX SOTA hoa restricted antenna morse code stealth antenna elecraft kx3 ham radio kx3 magnetic loop qrp antenna JT-65 WSPR calling cq digital modes mag loop qrpp reverse beacon network ssb #proudofmyson 10 meter 2 meter portable j-pole CWOpps EI13CLAN JT-9 Wake Island camping copper j-pole. You can use a 3″ piece of 1″ diameter PV and about 50 turns of 26 AWG magnet wire. Antenna installation can sometimes be measured by the SWR of the installation. Or the antenna you hide in your attic, because of the coming Zombie invasion of course. End Fed Half Wave (EFHW) Antenna Upgrade Part 1 - The Matching Transformer For several years the EF-10/20/40 MKII “EndFedz “ has been my main station antenna for HF. This validates the successes of many users of HF EFHW antennas such as the LNR EF-10/20/40. An EFHW antenna puts the feed point where your standing wave gives you high voltage, low current. Due to the high impedance feed point, the antenna. End Fed Half Wave Antenna, 7. The general class phone portion in 80m has too high swr to use without tuner (about 4:1). Installing an End Fed HF Antenna VK5STU. This means it creates a half wave length for the 40 meter band. We are running a reduced service due to the covid 19 pandemic , stop at home, stay safe. Com W0QH 2018-12-26T15:58:23-06:00. Half wave dipole antennas are generally considered the reference point for all antennas in ham radio, especially on HF. Whether you're QRP backpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $49. Designed as a 20m antenna. I am a particular fan of terminated antennas- the folded dipoles- and in this case, a terminated long wire. Get the complete kit and get on the air in minutes!…. It will present its parameters, so anybody with basic home-brew skills will be able to build it. Unfollow end fed antenna to stop getting updates on your eBay Feed. QRP PORTABLE: 5W/10W PEP "STEALTH" EFHW ANTENNA. Nevertheless, I will also describe, how it is designed, if one decides to embark on building it for different bands. How to determine the wire length Antenna Wire – longer for better low band operation Coax Cable – typically 50-75% of antenna length Counterpoises/radials – use non-resonant length, raised, multiple with various lengths Bands Covered (meters) Wire Length (feet) Minimum Coax Length (feet) 40-30-20-15 35-43, 49-63, 70-85 35. In it's simplest form, the EFHWA is nothing more than a 1/2 wave length wire radiator and a single 1/4. There is a significant difference; and, unless I misunderstand, this antenna is actually operated as a resonant antenna on 80, 40, 20, 15 and 10m, and a near-resonant one on 30m, and a non-resonant one on 17. UPDATE: Practical field tests verified this - that altering the line length of the antenna (shortened by 2 metres in one instance) a vswr of 1:1 could be achieved. For example, if you are getting RF problems on 20m (14MHz), a PVC-coated wire or counterpoise cut to a length of 5m may resolve many of the EMC issues. Antenna length: 84 cm Including bracket: 100 cm Weight 800 g Color White Material ASA Connector SMA-m standard or upon request Cable LMR195, 2 meters standard or upon request Temperature -40°: + 70° Other This part is RoHS compliant. Then the antenna must have an electrical length of 66 feet, and suitable feedlines would have electrical lengths of 8, 14, 16, 24, 25, 41, 46, 77, feet.   100pf capacitor will be placed between the ground and center conductor. A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m The 80-10m EFHW This is a shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. Fixed-length antenna impedance varies with frequency due to physical dimension dependent capacitance and inductance. As typically installed, it is a compromise antenna but great for portable use because it is easy to pack and easy to install. I am a particular fan of terminated antennas- the folded dipoles- and in this case, a terminated long wire. 2MHz, ground mounted) SWR - Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. Post updated 5 May 2019, scroll to the bottom for details. Due to the high impedance feed point, the antenna. End-fed, half-wave antennas (EFHWs) are a half-wavelength long and are resonant antennas on the band of interest. 85 meters and 67 feet/20. G5RV - true G5RVK Antenna - $57. 5-30 MHz Screwdriver Antenna Also Avaliable in 3/8x24 Connector. Zak W1VT ARRL Senior Lab Engineer: May 3rd 2018. I did perform S11 on both to trim for the 30m band. The RadioWavz EFH antennas are a perfect match for SWL listening, and can even be used for transmitting up to 25W AM and 200W PEP/CW for Amateur Radios. Credits to VK2ZOI. Several ways exist to bring the wire’s high impedance feedpoint closer to the desired 50 ohms, including use of a 49:1 or 64:1 unun, which eliminates the need. MFJ-1984LP, $39. Here is the pattern of the 160/80 meter antenna on 3. The overall length, deployed, is 52″, and can be disassembled to it’s longest piece being only 6. The antenna length was calculated as 300/2450 = 0. The popular End-Fed Half-Wave (EFHW) Antenna is an easily portable, high-impedance (2,000-4,000 ohm) wire antenna that resonates on its fundamental frequency and all harmonics above. 5:1 • No Tuner needed • Bandwidth: Over 750 kHz. It will present its parameters, so anybody with basic home-brew skills will be able to build it. For example: The 20-meter band covers 14. Since my unit was to be used in the field I wanted the option to forego using coax cable altogether. Our motto: " Treat others exactly the way that you want to be treated. Using the EFHW for 20m at GB0CMS 3. A so-called random wire antenna is an end fed antenna. Assemble Section M and the stub part of the antenna, including the in-line coupler on the top of the inside stub element (the one inserted into the T), as shown in Figure 1. Building an End-Fed Half-Wave antenna Posted by Matt under Amateur Radio , Antennas , Uncategorized Leave a Comment It's fun to take a minimum of equipment out to a high place, lob a half-wave long wire antenna up into a tree, or support it with a fibreglass pole, and off you go - but such a long wire typically has a high (2. This is a very simple antenna to build. Figure 3 is the end fed half wave antenna deployed as a sloper, and I usually only use this antenna on 20 meters and up. com EFHW 8010, It's my base antenna I use with the 7300, it works well on 160M too with my external MFJ manual tuner. Part 2 - A 40 Meter EFHW with a "Radiator" wire and various length "Coax-as-Counterpoise" wires is analyzed - We will see that the common-mode current is almost always LARGER on the coax shield some distance away from the feedpoint, which is why the "counterpoise" radiates and is called "the other half of the antenna". 30 Watts QRP, 80-10 Meters, 132 feet. この図には、Moxon's Ideal End Fed Half Wave Length Antennaとあって、1990年にアマチュア界の世に出たらしいですが、ということは、本来はモクソン氏関連の軍用、臨時の簡易アンテナなのでしょう。. EZ Hang Square Shot Kit. A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m Steve Nichols G0KYA A shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. Jun 18, 2018 - The finished End Fed Half Wave antenna coupler. 2m) long NO TUNER needed for 4 main bands! Resonant on 40/20/15/10m (WARC bands with Tuner) 1 Kw-max. Natural resonant frequencies depend on the overall length H + L + S. Suppose a plot is made of the antenna length desirability for one side of a half wave dipole for 80 metres. Unfollow end fed antenna to stop getting updates on your eBay Feed. It is sometimes said that common mode current flow on. This article will describe a 40/30/20m band end-fed half wave antenna, focusing on its matching unit. 30 Watts QRP, 80-10 Meters. However the physical length is slightly different to that of a half wavelength in free space. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. That is it. Fixed-length antenna impedance varies with frequency due to physical dimension dependent capacitance and inductance. EZ Hang Square Shot Kit. MFJ has six models to choose from, full length 80-10 Meters (132 feet) or 40-10 Meters (66 feet) and QRP, mid-range 300 Watts or high power 800 Watts. A so-called random wire antenna is an end fed antenna. Unfollow antenna end fed to stop getting updates on your eBay Feed. 2MHz, ground mounted) SWR – Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. Antenna installation can sometimes be measured by the SWR of the installation. The antenna will be resonate at the Amateur bands specified for each model with very low to almost flat SWR. ó , kdyh kdg \rxu pxowledqg hqg ihg dqwhqqd lqvwdoohg khuh lq 6lqjdsruh iru d ihz zhhnv qrz dqg dp yhu\ sohdvhg , xvhg wkh zluh iurp p\ suhylrxv dqwhqqd zklfk lv ihhw orqj ,w zrunv ehdxwlixoo\ , kdyh lw. MFJ-1982HP EndFed 1/2 Wave 800W 80M-10M Wire Antenna 132 feet. Problems With End Fed Half Wave Antennas •#1 Problem: Common mode currents on feedline •RF in shack •High noise levels on receive •Feedline and grounding can affect SWR and tuning •Isolating the feedling from the antenna can be difficult, even with a common mode choke •High voltages, even at low power •FCC RF exposure limits can be exceeded at low power levels. 5 foot wire (about a half wave on 20 meters) to 50 ohms. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. Sleeve Dipoles are realized by the addition of a metallic tube on a coaxial structure. A much better type of antenna then a simple quatre wave and that has more gain is the 1/2 wavelength vertical. A High Efficiency Extended Length Mobile Antenna. Loading Unsubscribe from VK5STU? Dipole, EFHW, Vertical, Windom antenna comparison - Duration: 13:34. Hi, For sale here is our End Fed Half Wave (EFHW) antenna for 10m-80m. 5MHz) therefore also resonant on second, third, and fourth harmonics, etc. NOTE 1: This original N2CX article was first published in the 72 newsletter back in 1997 or 1998. Notice how the feedpoint is not quite as high impedance as the top of the antenna. vibrator with 2. Q: A: What does EFHWA mean? EFHWA as abbreviation means "End Fed Half Wave Antenna". A quater wave antenna's radiation pattern like a dome. The weather-tight type N male connector attaches to the antenna’s type N female connector. The quarter wave matching section transforms the high impedance feedpoint of the EFHW to a lower impedance that the KX3 can handle. Electrical size of antenna is the physical dimension defined relative to wavelength. Rock-Mite transceiver for 40m. A piece of wire of almost any length can be used as an antenna on the HF bands. Get an aluminum pole with a 1 ⁄ 2 in (1. For example, if you are getting RF problems on 20m (14MHz), a PVC-coated wire or counterpoise cut to a length of 5m may resolve many of the EMC issues. Buy End Fed Antenna and get the best deals at the lowest prices on eBay! Great Savings Free Delivery / Collection on many items Radiowavz EFH80 80M End Fed Half Wave Antenna 200w SSB/PEP 25w AM Length 125' 8" £82. Is vertically polarized and has a predictable, non-directional pattern. Antenna Length = 34. All these mechanisms replace the missing part of antennas like the end fed random length wire and the quarter wave vertical or the end fed half wave wire. Choose a frequency that’s in the middle of the band you wish to operate on. 5 - 54 MHz 300 watts #9130sw - Wing nuts Balun Designs - Length of counterpoise should be approx. Figure 1 below shows the business end of the end-fed dipole with source and series reactance Xs (a capacitance) combine to yield a 50 ohm feed impedance for the source. An end fed half wave antenna is one of a specific length depending on the frequency that it…. The stake is now a smaller 6" stake which is easier to deploy. Due to the high impedance feed point, the antenna. Hams in general, and QRP'ers in particular, are always on a quest to find the "ultimate" antenna. Introduction: A collinear (or co-linear) antenna array is an array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array. The antenna system consists of a 40-10 EFHW (~60' Wire matched to a QRPGuys EFHW transformer mounted on a DIY wire winder cut from a yard sign), 5 aluminum tent pegs, 2 pieces of shock or bungee cord for tying off the antenna ends, a 25' BNC terminated RG-174 coax, and a 14-1/2 ft fiberglass fishing pole with DIY collar and guy lines. Detailed construction notes 6. Updated April 2020. End Fed Half Wave (EFHW) Antenna Upgrade Part 1 - The Matching Transformer For several years the EF-10/20/40 MKII “EndFedz “ has been my main station antenna for HF. 66 – ZL-Special Beam Antenna for 15m. Long wire antenna for portable operations. ó , kdyh kdg \rxu pxowledqg hqg ihg dqwhqqd lqvwdoohg khuh lq 6lqjdsruh iru d ihz zhhnv qrz dqg dp yhu\ sohdvhg , xvhg wkh zluh iurp p\ suhylrxv dqwhqqd zklfk lv ihhw orqj ,w zrunv ehdxwlixoo\ , kdyh lw. The EZNEC screenshot below is the current distribution on 15m. Huntsville Store: Skip to the end of the images gallery. Obviously, an EFHW antenna has a "half-wave" length only at one specific frequency. Complete with 2 end insulators and 1 centre insulator; Resonates on 10m, 20m, 40m & 80m; Works on 30m, 17m, 15m, 12m, & 6m with antenna tuner. On Sunday, 3rd of June, I headed of early to activate the White Dam Conservation Park VKFF-1122. This material is very strong yet can easily be coiled like a rope for portable work. Any dipole antenna consists of two identical elements in the form of metal rods with the feedline between them. Maximum efficiency and absolute minimum feedline radiation will occur when the antenna is tuned as in the steps above. As a consequence, this study proposes a simple method to easily determine the radiation pattern properties of an L-shaped wire antenna, by just knowing the ratio between the length associated to the horizontal arm (hereafter L x)andtheheight. The antenna is up 30 feet in the middle and the ends are at 26 feet. The purpose of this group is to explore the use of an end fed half wave antenna. 1' 56:1 Z Ratio Unun 32' 4" RG-8X + 2' 7" RG-58A/U Type Coax AA-54 Antenna Analyzer OSL Calibration at Unun Resonant Frequencies = 13. Click on Calculate and the opposite value will be displayed in feet and inches or frequency in megahertz (Mhz). I find, however, that a bit of coax causes them to. Credits to VK2ZOI. Length can be adjusted by looping free end over to shorten. And I'm going to keep this VERY simple. He loved working 20 meters, but the housing community he moved into prohibited antennas that could be seen by the public. Both can be used on multiple bands though the random length one may have a slight advantage there if you. 2MHz, ground mounted) SWR – Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. The original design has a 27/3 turn ratio ( 1: 81 ) on a small 43. Works with a 4:1 UNUN. UNUN 1:64 - 1:49 Variable For End Fed Half-Wave (EFHW) antenna 100+W - $14. Unlike many END FED antennas on the market, this one does not require the Antenna tuner. Part 2 - A 40 Meter EFHW with a "Radiator" wire and various length "Coax-as-Counterpoise" wires is analyzed - We will see that the common-mode current is almost always LARGER on the coax shield some distance away from the feedpoint, which is why the "counterpoise" radiates and is called "the other half of the antenna". MFJ-1984LP EndFed 1/2 Wave 30W 40M-10M Wire Antenna 66 feet. ó , kdyh kdg \rxu pxowledqg hqg ihg dqwhqqd lqvwdoohg khuh lq 6lqjdsruh iru d ihz zhhnv qrz dqg dp yhu\ sohdvhg , xvhg wkh zluh iurp p\ suhylrxv dqwhqqd zklfk lv ihhw orqj ,w zrunv ehdxwlixoo\ , kdyh lw. For optimum performance, the antenna should be constructed. The 20m-17m-15m three-band trapped EFHW Where it started in 2009: I like half wave dipoles. Further Considerations Now that we've said all this, we should discuss the trade-offs between having the perfect lengths of coax vs. It requires a high impedance matching device: Either a tapped resonant. The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. See this link for more info. This is less important if you have a resonant half wave or multiple but you don't have that. No long counterpoise, radials or feedline required. End Fed Half Wave Antenna, 40/20/10 meters, QRP, 25W CW/SSB, 41 ft. The overall length, deployed, is 52″, and can be disassembled to it’s longest piece being only 6. As you mentioned, deploying portable antennas may result with varying antenna resonant solutions. These antennas can be mounted horizontally, vertically or as a sloper. Being a half wave, no radials or counterpose wires are needed. If a longer antenna is desired, the provided antenna can be lengthened. This set-up is a great DX antenna and on 40 i'm getting "great signal" reports. The smallest antenna should be my holiday antenna about 11-12m long and used for Dualband 10/20m only. End Fed Half Wave (6. Electrical size of antenna is the physical dimension defined relative to wavelength. 30 Watts QRP, 80-10 Meters, 132 feet. INTRODUCING THE. In radio and telecommunications a dipole antenna is the simplest and most widely-used class of antenna. A short length of 20mm OD PVC electrical conduit was used for the coil former. 20-30 feet but NOT resonant. I came across the following antenna which covers the 80-10m bands with no traps and just one loading coil. In an EFHW the counterpoise can be small without diminishing the efficiency of the antenna. The example given was for a Bluetooth antenna with a frequency of 2450MHz. The antenna system consists of a 40-10 EFHW (~60' Wire matched to a QRPGuys EFHW transformer mounted on a DIY wire winder cut from a yard sign), 5 aluminum tent pegs, 2 pieces of shock or bungee cord for tying off the antenna ends, a 25' BNC terminated RG-174 coax, and a 14-1/2 ft fiberglass fishing pole with DIY collar and guy lines. It is basically an end fed half wave dipole on 20m/40m and an end fed full wave dipole on 10m. 38-44, 55, 60, 68-73 Feet. End fed half wave antenna length. Unun 1:64 - 1-49 Variable For End Fed Half-Wave (EFHW) antenna 100+W. Introduction: A collinear (or co-linear) antenna array is an array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array. " The very valid reason for this is that the high impedance of the feedpoint was outside the range of most transmitters and external tuning units. The EFHW 8010 1KW (I. This would require a 6:1 turns ratio. DOUBLE BAZOOKA antenna is an extremely broad banded Half Wave Antenna which can operate efficiently. I wound a new transformer, but now on a thinner plastic tube. Total Length 39 Feet (12Meters) 2) GEK EFHW- 8010A (200w) 80-40-20-15-10m. The only downside to EFHW antennas is the need to cut a different wire for each band. Stainless Hardware, UV resistant materials throughout. Antenna Theory - Full-Wave Dipole - If the length of the dipole, i. The shortest antenna that has a chance of tuning all bands has an electrical length of 143 feet and should be trimmed to give a quarter wave resonance at 1. I setup a little over 10m of wire with a 1m counterpoise. If properly implemented this antenna can be very good. 2MHz, ground mounted) SWR – Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. A High Efficiency Extended Length Mobile Antenna. This is a design by my friend John, KN5L. 8 metres long. An end fed half wave antenna is one of a specific length depending on the frequency that it is to be used on, for example, an end fed half wave antenna for 80 meters is about 130′ long. Posts about EFHW Antenna written by Andrew Williss. The antenna cannot be an actual 1/4 wave length on any ham band. Skip to the beginning of the images gallery. Some designs connect one end of the secondary coil to the antenna socket, which then makes the coax shield act like a counterpoise. Due to the high impedance feed point, the antenna. A very simple antenna to make, deploy and use is an end fed wire antenna. MFJ-1982LP, $49. 52 turns of 24 gauge wire is wound on the former. 5MHz) therefore also resonant on second, third, and fourth harmonics, etc. Total Length 39 Feet (12Meters) 2) GEK EFHW- 8010A (200w) 80-40-20-15-10m. For optimum performance, the antenna should be constructed. Portable EFHW = NBD. Other designs, such as the popular commercial EFHW-8010, connect it to s separate screw/output so that you can either connect a short counterpoise or connect it to a ground rod. But, even a poor system may be usable on the digital mode FT8 or CW for making very short contacts. Thus 8, 16, 32, 68 lengths are ruled out. Brand: RadioWavz. The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). PowerMax™ antenna cables offer the lowest signal loss for cellular and WiFi frequencies. 5/8 antenna could have about 3. Model 4132 - 4:1 Unun for Multiband Verticals and Random Wires, 2kW. The antenna length was calculated as 300/2450 = 0. 102' Radiator length (#14AWG HD stranded copper wire) fed with heavy duty 300 Ohm ladder line. I instead made two antennas: one center-fed and one end-fed. With a power. 5MHz) therefore also resonant on second, third and fourth harmonics etc. "Counterpoise" Length" Jim Lamb says:. ANTENNA PERFORMANCE CHART NUMBER TYPE BAND LENGTH PL-259 Standard UHF Connector Male KD9/19 5/16-24THDS. The coax connector is at one end of the dipole, where it is most needed. Here's a few antenna matching devices I've gathered and some experience with the antennas. 05 wavelength counterpoise to work properly. The results are conveniently displayed in inches, centimeters, feet and meters. 2MHz, ground mounted) SWR - Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. It's been a couple of years now since my first post on EFHW Antennas. Check this: EFHW Straight If you cannot deploy the antenna straight, the following link will help you will understand why it is advantagous to make an "L" bend at 1/2, 1/4, or 1/8 points if you have to make a bend:. MFJ-1984LP, $39. G0KYA's HF End Fed Half Wave (EFHW) antenna – construction details Introduction The EFHW monoband matching unit (inspired by AA5TB) allows for a half wavelength of wire to be connected, giving a 50 Ohm impedance match to the transmitter (without a ground plane or ATU) at the frequency of operation. No field guess work. Nevertheless, I will also describe, how it is designed, if one decides to embark on building it for different bands. In a perfect world I would have one dipole wire for the 30m test with two feed positions. Please wash your hands and practise social distancing. Doublet – Multi-band antenna that is not resonant on a particular band. Length can be adjusted by looping free end over to shorten. A very simple antenna to make, deploy and use is an end fed wire antenna. Maple Leaf Studio is a labor of love.    The antenna wire will be 14ga stranded at about 134ft in length. I instead made two antennas: one center-fed and one end-fed. Length is equal to 1/2 of the wavelength for the frequency of operation. Doing so will interfere with antenna performance. The MyAntenna 8010 End Fed is an End-Fed Half-Wave (EFHW*) antenna. They are easy to make and easy to. But performance is down about 8-12db on a dipole on 80m. First, setup your end fed half wave tuner (ex. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of All-Band 80-10 Meter End-Fed Half-wave Antennas - MFJ 1982,1984 Cover all HF bands with one single wire and no tuner! to ensure great performance in a wide range of operating conditions. Antennas are defined in terms of height H of the vertical section, length L of the horizontal section, and conductor diameter. This formula to obtain the length of a half-wave dipole antenna will give a good ballpark value to start with. This kind of antenna can also be installed as an invertd V or an inverted L that helps fit it into many gardens. The measurements below are for building a simple Dipole Antenna. As we know, any length of wire will present resistance (impedence) to the feed line (your coax) and the radio, and it also makes sense that the longer the wire gets, the more impedence will be presentas high as 5Kohms or more. An EFHW antenna with high impedance, fixed ratio, Ferrite transformer Unun is but one antenna solution. Is vertically polarized and has a predictable, non-directional pattern. 2(a): You can see that when erected in a straight line the dipole is quite directional. 0 dBd or zero gain). Components of a End Fed Half Wave Antenna ••Radiator length is 1/2Radiator length is 1/2 λoftheoperatingfrequencyof the operating frequency. 83m for the upper element. The QRPGuys Mini 80m-10m No-Tune End Fed Half Wave Antenna. End Fed Half Wave Antenna (EFHW) AA5TB Orientation vs Propagation Video: Endfed Fundamental The End Fed Half Wave Antenna by Steve Yates - AA5TB An End Fed Half Wave Length Antenna is a variation of the much more common half wave length dipole antenna. Related Pages: Groundplane Verticals (they are generally end-fed 1/4 wave radiators). 12 dBi down to 2. Your first antenna - the half-wave dipole. The End Fed Half Wave Antenna (EFHWA) is a popular antenna for portable use. Click on Calculate and the opposite value will be displayed in feet and inches or frequency in megahertz (Mhz). Assemble Section M and the stub part of the antenna, including the in-line coupler on the top of the inside stub element (the one inserted into the T), as shown in Figure 1. A simple, easy solution for matching your HF rig to end-fed half wave or random wire antennas. Introduction: A collinear (or co-linear) antenna array is an array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array. A fixed ration Unun EFHW antenna can be tuned by adjusting length of the antenna. EFHW-8010P- 200W Portable or Stationary Multi-Band End Fed Half Wave Antenna. This is essentially the same as the Hendricks tuner unit, only without the case. Inverted-L EFHW Antenna? To answer the question, a wire antenna model was developed* based on data reported by Danny Horvat, N4EXA and E73m (MyAntennas. 5 lbs and it all packs. END FED antennaEFHW-8010-HP Multi-Band End Fed Half Wave Antenna- NO TUNER NEEDED! EFHW-8010-HP 1500W Multi-Band End Fed Half Wave AntennaThis is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Hi chaps! I am soon to attempt to build a 20m EFHW antenna similar to that described by G0KYA in his blog. The Par Electronics EF-SWL is an end-fed short wave antenna optimally designed for 1-30 MHz reception. Lengthen or shorten by 1/4 wave and the tuner will handle it fine. Distance from center of antenna to the center of the coil in feet (Must be less than half the total antenna length given above) Enter a distance between 0 and 250 feet that is less than half the total antenna length. The drawings illustrate the set up, I hope. An EFHW is simply a half-wave length of wire and a matching device, and that's it. Experience has shown that most external tuners and many internal tuners will tune 80–6 meters with an antenna length of 22’ to 30’. I was able to get the MyAntenna EFHW-8010 installed the weekend following it’s arrival. A dipole is basically a mono-band antenna. 5dBi gain over a 1/2 wave length antenna (mounted same height) by shaping some energy from vertical direction to the side. about one to two feet long is a good length for Section M. multi-band antenna. These antennas can be mounted horizontally, vertically or as a sloper. Reading between the lines I am making a guess that your EFHW antenna is from Myantennas. Due to local ground conditions, antenna height and feed line length, SWR may vary and an antenna tuner may be required or some bands to bring SWR at end of feed line to. Resonant antennas cut to the exact frequency, in the middle portion of the band, and used with a tuner of sufficient size, can tune several bands. 13 thoughts on “ Shortwave Antennas Page 10 ” Marc on September 23, 2018 at 12:28 PM said: I hope somebody will give me a property where I can put a 150 KHz LW wire antenna. No ground plane or counterpoise is needed. JK Antennas will selectively and progressively make available most of the legacy Force12 yagi models such as the XR5. The overall length of wire required for the loop is found by using this formula: Length (feet) = 1032 / f MHz Therefore a triangular full wavelength loop antenna for 40 meters will require about 145 feet of wire. 3:1) on 80m and 40m, and below 3:1 on 20, 15 and 10m. wire length. The entire antenna is 12 meters long mechanically, but forms an electic length of 20 meters for the 40 meter band because of the coil. Details about K4EDF 7MHZ 14MHZ 21MHZ 28MHZ 5-35MHZ End Fed Half-Wave EFHW antenna 100W HAM. Obviously, an EFHW antenna has a "half-wave" length only at one specific frequency. The 20m-17m-15m three-band trapped EFHW Where it started in 2009: I like half wave dipoles. How to determine the wire length Antenna Wire - longer for better low band operation Coax Cable - typically 50-75% of antenna length Counterpoises/radials - use non-resonant length, raised, multiple with various lengths Bands Covered (meters) Wire Length (feet) Minimum Coax Length (feet) 40-30-20-15 35-43, 49-63, 70-85 35 40-30-20-17 35-45, 54-64, 67-77 35. Wound at 3. Since I enjoy using End Fed Half Wave antennas so much I built a small coupler to use with my Rock-Mite. If fed at the end (a. Suggested wire lengths for 1-31 Mhz operation. The antenna system consists of a 40-10 EFHW (~60' Wire matched to a QRPGuys EFHW transformer mounted on a DIY wire winder cut from a yard sign), 5 aluminum tent pegs, 2 pieces of shock or bungee cord for tying off the antenna ends, a 25' BNC terminated RG-174 coax, and a 14-1/2 ft fiberglass fishing pole with DIY collar and guy lines. Components of a End Fed Half Wave Antenna ••Radiator length is 1/2Radiator length is 1/2 λoftheoperatingfrequencyof the operating frequency. An EFHW antenna with high impedance, fixed ratio, Ferrite transformer Unun is but one antenna solution. It seems to work best when the transformer is from ~1m to 2m from the ground. INTRODUCING THE. Armed with technology it was time to revisit this "no-tune" portable antenna. 67 – Half-Sloper Antenna for 160m. Random Wire Antenna Lengths. This makes keeps the weight and bulk down while delivering a very strong antenna element. Unun 1:64 - 1-49 Variable For End Fed Half-Wave (EFHW) antenna 100+W. This would require a 6:1 turns ratio. Long wire antenna for portable operations. 30 Watts QRP, 80-10 Meters, 132 feet. com EFHW 8010, It's my base antenna I use with the 7300, it works well on 160M too with my external MFJ manual tuner. This formula to obtain the length of a half-wave dipole antenna will give a good ballpark value to start with. The magic of End Fed Half Waves / EFHW I have noted recently the increasing popularity of the so-called End Fed Half Wave antenna, though the term often includes harmonic operation of the antenna. The antenna wire (1/2 wave long) is soldered to the top of the coil as shown in figure 2. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. 060 MHz a EFHW is 468/14. I get good DX with this antenna on SSB Phone. If my antenna is 65 feet away from my radio, I need a 14. Our motto: " Treat others exactly the way that you want to be treated. HF END FED Antenna EFHW-7510-2K 2000W 75-10m / NO TUNER NEEDED!! / 132 feet long - $229. 95 (kit) G5RVA $74. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. The length of wire on each side of the balun to the resistor should be within about 6ft (2m) of the same length, to maintain good SWR and balance of the antenna. 3:1) on 80m and 40m, and be. EZ Hang Square Shot Kit. First, setup your end fed half wave tuner (ex. This validates the successes of many users of HF EFHW antennas such as the LNR EF-10/20/40. 3/30/2018: Note: Throwing line for antenna kit will now be 100' of mil grade 1. 6m Omni Antenna. The RF power wave reshaping help taking some of the RF power emitting vertically to the horizontal radiation. 05 wavelength counterpoise to work properly. Natural resonant frequencies depend on the overall length H + L + S. The 9:1 will make contacts but can also light up the coax with hot RF. The best way to tune an EFHW antenna, IMHO, is with a tank circuit coupled to a feedline with a secondary winding that isolates the feedline from the antenna. 80-10 Meters - 130' ft. These antennas offer a simple, effective method of putting up an antenna that requires no tuning, no tuners-they can be any length ( there are some minimums depending on how low the desired frequency is) plus they are good in noisy environments. I added a 1:1 choke at the end of the feed line running from the feed point to the ground. The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. Nevertheless, I will also describe, how it is designed, if one decides to embark on building it for different bands. S Stealth #18 AWG black wire Description EFHW-8010P- 200W Portable or Stationary Multi-Band End Fed Half Wave Antenna This is a 200W version of popular EFHW-8010 End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. A special case of this, is the End-Fed Half-Wave (EFHW) antenna. G5RV - true G5RVK Antenna - $57. And while I am very happy with how it works, with the low SWR and ease of installation, I was somewhat misled by the 1KW "I. I made a new Link Multiband EFHW for 15/20/40 2 weeks ago. But performance is down about 8-12db on a dipole on 80m. For example: The 20-meter band covers 14. Fast and secure payment. With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun including a tuner or simply with a tuner is one possible solution. Doing so will interfere with antenna performance. Tribune Media’s Antenna TV, the multicast digital channel devoted to vintage television shows, will run full-length episodes of “The Tonight Show Starring Johnny Carson” nightly at 11 p. 2(a): You can see that when erected in a straight line the dipole is quite directional. 8-2 MHz) operation, an antenna with an electrical length of 74 feet should suffice and should be trimmed to give a quarter wave resonance at 3. If you want to know why, do a little reading on the difference between a resonant end-fed halfwave and a random-length end fed antenna. 5MHz) therefore also resonant on second, third and fourth harmonics etc. It works great, I use it on 40m, 20m and 15m with no tuner needed (under 1. The ULTIMAX DXTREME end-fed antenna covering 1. Note that the point of this article is not to provide definitive values of impdances vs. In radio and telecommunications a dipole antenna is the simplest and most widely-used class of antenna. This is an End-Fed Half-Wave (EFHW*) antenna for 75m (3. This is a 200W version of popular EFHW-8010 End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. 5kΩ to 3kΩ. Technically a true "longwire" needs to be at least one wavelength long, but Hams commonly call any end-fed wire a longwire or random wire antenna. The fastest way to do that, and put out a decent signal too, is with the EFHW - an antenna with a forbidden length. 1 800 ANTENNA (268-3662) 5 PORTABLE RADIO ANTENNAS Antennas are not to scale The following chart summarizes performance, size and cost parameters for various antenna types. Yeah, that title is a mouthful! And for something with such a long name, it sure is a tiny little kit. Here's a photo of the bits in a box being tested. Time Owned: 0 to 3 months.  The most common half-wave antenna is the center-fed dipole, whose impedance is approximately 72 ohms. We extended this length to 122 feet. Yellowjack tower tool with lanyard. It is a resonant Half wave low on 80m (3. A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m The 80-10m EFHW This is a shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. The closer an antenna length (including feeder) is to an odd multiple of ¼ wavelength the better. An end fed half wave antenna is one of a specific length depending on the frequency that it…. Somewhere on the internet I read that a small counterpoise is optimal, so chances are it was omitted in the design you mention to make the antenna smaller, or because it didn't offer a noticeable improvement. The Antenna Farm : Extra Length Cable - VHF & UHF Mobile Radios Radio Accessories VHF & UHF Hand Held Radios Antennas Mobile Antenna Mounts SWR/Power Meters Adapters Coaxial Cable Two Way Accessories Antenna Accessories DC Power Supplies Coax Cable Accessories Connectors Aviation Radios Repeater Systems Towers & Accessories Duplexers Diplexers & Triplexers VHF & UHF Base Stations Base Antenna. Every Antenna is cut to a precise length to accomodate that particular band. Hams in general, and QRP'ers in particular, are always on a quest to find the "ultimate" antenna. Feeding them is therefore much simpler for portable ops since only one side needs to be elevated.   100pf capacitor will be placed between the ground and center conductor. Unsurprisingly, both are the same length. ; Stainless Hardware, UV resistant materials throughout. 40m, fed buy a separate coax. Use insulated wire; #18 AWG (1mm) insulated wire is sufficient size for 500 Watts transmitter power. 40 results for antenna end fed Save antenna end fed to get e-mail alerts and updates on your eBay Feed. Length, Stainless Steel Hardware, SO-239 Connector, Each Not Yet Reviewed Part Number: PEZ-EF102040-239 More Detail. This is an End-Fed Half-Wave (EFHW*) antenna for 75m (3. In other words, it was modeled as two half wavelength wires end-to-end and the length of each was kept the same but adjusted to obtain a purely resistive match. While searching for an alternative to my Linked- Dipole I tripped over the posting of Pedro, CT1DBS, illustrating an end-fed half-wave (EFHW)- Dipole with Traps. The popular version of the Terminated Folded Dipole is ninety feet long. MEF-330-1K Multi Band End Fed Half Wave Antenna Transformer. The End Fed Half Wave Antenna (EFHWA) is a popular antenna for portable use. Portable End-Fed 40-6 Meters Dipole Antenna. End-fed antennas at an affordable price. DOUBLE Bazooka Antenna 27 Mhz CB DXer. The antenna has a full 300kHz bandwidth on 80m between 3:1 SWR points. 13 dBi (which equals 0. Beam length has a significant effect on SWR response. The larger the wire, the wider the bandwidth. Enter a length between 1 and 500 feet. Due High Impedance feed point, the antenna is less. The 50' to 100' lengths are made with DA340 cable to minimize signal loss. #22 AWG wire is sufficient for 100 Watts. ) than a ground plane antenna with the feed point at the same height. If a longer antenna is desired, the provided antenna can be lengthened. Introduction and Purpose. PowerMax™ antenna cables offer the lowest signal loss for cellular and WiFi frequencies. The Wire Size can range from 16 AWG to 12 AWG. Inverted L Wire Antenna •Remote tuner required •Should not be a resonant length •70 or 140 ft recommended tuner Ground & radials Coax to rig Mount near ground level Run wire up to eve and isolate under eve of the house. This choke was made with #14 house wire and has a bit of an impedance mismatch so the antenna tuner is needed. Even the KX3 ATU can't match this 33'3" wire directly, it is too high of an impedance. For optimum performance, the antenna should be constructed. I wound a new transformer, but now on a thinner plastic tube. HF END FED Antenna EFHW-8010-2K 2000W 80-10m / NO TUNER NEEDED!! / 130 feet long - $239. EFHW-8010-1K Multi-Band End Fed Half Wave Antenna. Dipole Antenna Calculator. End Fed Half Wave (EFHW) Antenna Upgrade Part 1 - The Matching Transformer For several years the EF-10/20/40 MKII “EndFedz “ has been my main station antenna for HF.