Counterpoise Length For End Fed Antenna

" I think you might want a counterpoise for use on the WARC bands. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. 47 free space wavelength) was determined by modeling the length required to obtain resonance (jX = 0) when the "counterpoise" was the same length. The solution is quiet obvious: With an end-fed wire antenna from a kite up in the sky led down to the radio on the ground. ) Their output coupling network is designed to efficiently handle higher impedance, optional end-fed antenna loads relative to the high plate impedance of a vacuum tube PA. There is much more that can be written about this antenna and its matching, but that was not my aim. All Band Single Wire Antenna,The Zeppelin. I do use it for other bands (12, 15, 17, 30m, in those cases it is a random length antenna) with the use of an antenna tuner. The figure 8 - blue line (grounded end) is exactly what I am experiencing with my end fed strung at my back yard. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. Connect the antenna analyzer or radio to the red BNC connector. Being an end-fed it does not really matter in which direction it goes in. I specifically wanted stranded wire. tached end because like all unconnected ends of antennas, there will likely be enough RF voltage to cause an RF burn, particularly at 100 W or higher. It is worked against a counterpoise which is connected to the shielded side of the coaxial feed point. 5MHz), therefore it is also resonant on the second, third and fourth harmonics. 5mm Diam Red plastic coated wire 12 off 4 m plastic coated counterpoise wires buried in the lawn, plus a 10m long insulated wire laid in the flower bed M6 wing nut to. For instance, at 14. They were asked to choose their ";favourite portable antenna" from: Ground-plane W3EDP Endfed Halfwave Single Band Dipole Random Length Endfed Doublet Linked Dipole Magnetic Loop Multiband Loaded Dipole Other The order the antennas were listed in was. 47 free space wavelength) was determined by modeling the length required to obtain resonance (jX = 0) when the "counterpoise" was the same length. 4m Coax End Fed Antenna The 4m flowerpot is made with 32mm solvent weld tube. The EFHW (End-Fed Half-Wave) antenna is one of amateur radio’s oldest antenna designs. Divide 234 by the desired frequency (in MHz) to get the length. On my 80/40 QRO end-fed I have no counterpoise, the coax is sufficient and just before it enters my shack I have an RF choke to avoid RFI which seems to be working fine, even with QRO power. End Fed Antenna Choices Recap End Fed Zepp uses ladder line for matching to coax End Fed Half Wave - even harmonics, requires special high impedance matching unit, high voltage at feed point Non-resonant end fed is shorter, uses simple matching, low voltage feed point, works many bands with shorter length,. End Fed Half Wave Antenna Coupler Schematic – 7-30MHz. "An Unorthodox Antenna"): an 84' long end fed and a 17' long counterpoise (6. Here is an ARRL. These single-band and multi-band antennas can be mounted horizontally, vertically, or as a sloper. An earth on the Rig might upset the tuning. A system of conductors, elevated above and insulated from the ground, forming a lower system of conductors of an antenna. The wire is more expensive than others but resists kinking and has a very rugged PVC coating. An antenna assembly, comprising: a feed port including a signal feed portion and a ground portion, said ground portion connected to a ground plane; an approximately 1/2 wavelength dipole radiator having first and second high impedance ends;. END FED 6–40 Meter Multiband HF Antenna Introduction This project produces an inexpensive, multiband, end fed HF antenna matchbox that is quick and easy to setup and use. The end fed offers many alternative options. Zepp Antenna by K4EFW. Ultra light, only 260 gram, end fed wire antenna for 3 shortwave bands 40m + 20m + 10m. 5 MHz, but you can loop the wire around the room and hide it from view. I tested all three configurations and found that #3, no ground or counterpoise, gave far and away the best results for me - SWR 1. In 1) we typically get CMC if there is an imbalance on one of the legs of a dipole or if an end fed antenna has insufficient counterpoise/radials. the Vertical Up-Leg of the Inverted "L" Antenna. You do need an ATU though. 4 of a wave length in length and spaced 3° is considered an excellent ground system and in case of high base voltage, a base. No ground plane or counterpoise is needed. Make sure to use fish line or other non conductive material for this purpose. G5RV Multi-Band Antenna by Louis Varney,. The coax will be about 23 cm in total resulting in 22pF. 3:1 or better on all bands. - The 1ST Step is finding / determining where you will locate. A system of conductors, elevated above and insulated from the ground, forming a lower system of conductors of an antenna. It should be possible to feed it from the operating position, though it is noted the feed point needs to be raised from the ground to reduce losses. The End-Fed Inverted “V” is a good compromise between performance and ease of installation since it requires only one center support, has a reasonably small foot-print, and provides good sky wave propagation. Current flowing into the antenna's end must be equaled, at that end point, by the same amount of current flowing into a ground or counterpoise of some type. The design of the antenna allows it to be installed in many ways. 05 of a wavelength on 40m. 40/20/10m End-fed Antenna Rig Things to note: 1. GAP MONOGAP20, MONOGAP-20, MONOBAND 20m VERTICAL. It's now available for sale on their site. The end-fed feature adds convenience, and makes it very portable. end fed antenna counterpoise length. The antenna wire is 26 AWG copper clad steel wire with a great "silky" jacket. 160M Is a Tough Band • Propagation quite variable, signals often not very strong, heavy QRN during the summer –Mostly a nightime band, varies a lot through the night –During the winter, 800 miles or. The coupler converts the high impedance end of the End Fed Half Wave antenna down to 50 ohms. •Requires a 0. All DXTREME models are a different design that work most efficiently with the length of wire is sold with. KH6JRM's Amateur Radio Antenna Topics: A tuned counterpoise antenna for 40-10 meters. 7kg hardware: stainless steel connector: gold pref-Teflon so-239 assembly just add 1/2 half wave wire to this transformer and tune the length your preference. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire. The counterpoise from Ultimax antennas consists of a single wire for about 6 feet and. Figures 7 & 8 show that the 100 watt compliance distances for this antenna are longer than for the previous examples for both uncontrolled and public areas respectively. End Fed Half Wave MultiBand Antennas – Need for a “counterPoise ~0. 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. In the case of the "EndFedz" EF-10/20/40 and its clones, where we are effectively using the coax as a counterpoise, we can meet this requirement by ensuring the feeder is at least 0. End Fed Wire Antenna. This worked quite well. 4 lbs, the Model 418 will operate from any 13. Using the T 130-2 torroid and 3 x 9 windings the XL would be 357 Ohm at 7. In effect the W3EDP is an EFHW for 80m (126 ft top, 17 ft. If it didn't, it would have no current at the ends. In theory the antenna end impedance should drop to about 1800 ohms. A short wire is all that is needed: about 0. ADVANTAGES OF THIS J-POLE. Verticals require radials , horizontal wires that run along the ground, to create the other "half" of the antenna. Your complaints of RF in the shack are to be expected and tough to kill unless the system is set up properly. It's a decent match on everything from 40m to 10m, but i was wondering about the effect of the length if the counterpoise. 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. 5ft counterpoise on 20m. but Hams commonly call any end-fed wire a longwire or more correctly random wire antenna. Return loss tops out at about 8dB. For better effciency with the counterpoise, you can build or buy (the MFJ Artificial Ground) a counterpoise tuner. Make sure to use fish line or other non conductive material for this purpose. This is a not a major increase with this particular example of height and earth type, although there are cases where improvement can be greater. The manufacturer claims no counterpoise is needed. RaDAR - 160m end fed half wave antenna building instructions Posted: 03 Jul 2017 06:21 AM PDT length of wire will be your radiator and the 20 meter length will be your counterpoise. Ideal balance of strength and flexibility. According to the plans, the radiator should be between 24′ and 60′ and the coax feeder (which acts as the counterpoise) should be 16′ or longer. 05 wavelengths at the lowest operating frequency. The main benefit is that the antenna feed impedance is around 2500 ohms and very little RF current flows into the RF earth or counterpoise. At the extreme end of this is the End-Fed Half Wave (EFHW) antenna, where the counterpoise is only a foot or two long, and the impedance is on the order of 1600~2400Ώ. The end fed half wave antenna can be operated with a small counterpoise, and in some instances, no counterpoise is used at all, although this is not necessarily wise. The antenna wire is 26 AWG copper clad steel wire with a great "silky" jacket. antenna system is not advised. It is worked against a counterpoise which is connected to the shielded side of the coaxial feed point. This article will initially concentrate on the half wavelength of wire and its use as an effective multiband antenna. 624 m long) which goes up some 25 feet (7-8 m), then over horizontally, at an average of 25 feet (7-8 m) above ground, to a tree at the far end of my property. ) Their output coupling network is designed to efficiently handle higher impedance, optional end-fed antenna loads relative to the high plate impedance of a vacuum tube PA. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. The picture makes it look a bit worse as the range is plotted from 6 to 7. A QRPGuys based EFHW inverted vee cut for 40 and covering 40, 20 and 15 meters without a tuner. So if I use a 21 meter long wire, I take a 10. Make sure to use fish line or other non conductive material for this purpose. But with an end-fed half wave there is less current flowing in the ground and it can become almost unnecessary. 4 lbs, the Model 418 will operate from any 13. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. This worked much better and gave good results on all bands. When the counterpoise, (the other half of the antenna), is clamped to the outer collar of the BNC connector on your HT antenna, it helps to prevent RF from coupling with your body, so your completed HT antenna "system" acts much like a center-fed dipole instead of an end-fed dummy load!. 3:1 or better on all bands. Dual Band - $55. Run at least 16ft of coax to antenna. Your feed line is essentially the counterpoise, so a separate one is not necessary if you want to keep weight. Make sure to use fish line or other non conductive material for this purpose. Re: Emergency Amateur Radio Club Hawaii = END FED 6–40 Meter Multibander. 05 wavelengths at the lowest operating frequency. It also formed the basis of the antenna I finally decided to use. It consists of a 30-ft length of. 5mm Diam Red plastic coated wire 12 off 4 m plastic coated counterpoise wires buried in the lawn, plus a 10m long insulated wire laid in the flower bed M6 wing nut to. there is almost always an imbalance in the feed line with end-fed antennas. Mine runs from the top of my porch -. The plans for it are available on the Emergency Amateur Radio Club of Hawaii's web site. The MyAntenna 8010 End Fed is an End-Fed Half-Wave (EFHW*) antenna. Maximum power is 75 Watts SSB on 80 meters and 100 Watts SSB on 40 through 6 meters. Whether you're looking for a portable antenna or trying to put up a covert antenna that really works and won't bother the neighborhood, this is a great solution. If possible, run the counterpoise away from or perpendicular to the antenna wire. Decided to try a stealth design. Technically a true "longwire" needs to be at least one wavelength long. In this configuration PAR End-fed half-wave antenna. However I do like these antennas, they work almost as good as a mono-band dipole would. If it didn't, it would have no current at the ends. Click on Calculate and the optimum length for that combination will be displayed in feet, inches and fractions of inches, and in meters. Dual Band - $55. It consists of 30ft of wire fed into a 9:1 UnUn (Unbalanced to Unbalanced). End Fed Wire: The first antenna that I put up was a simple end fed wire. (Those kits also include a substantial ground radial system. Here are instructions for making a multiband end-fed half-wavelength antenna that works on 17, 20, 30, and 40-meter bands. I can mount the Feed end up to 30' high. Mine is about 30-40% of the length of the radiator (just one wire counterpoise), but I was wondering. Though a short conductor is shown to the right of the right hand feed line wire, the length is not specified or discussed in the accompanying text. I have seen a measurement on the Dutch end fed with an antenna analyzer. « on: February 07, 2015, 01:23:30 PM ». Technically a true "longwire" needs to be at least one wavelength long. I figure one can't have too many antennas and this one would be a quick build. Long-wire antennas require a length greater than a quarter-wavelength (λ/4) or half (λ/2) of the radio waves (most consider a true long wire to be least one wavelength), whereas random wire antennas have no such constraint. Connect the antenna analyzer or radio to the red BNC connector. Long-wire receiving antenna mainly used in the low frequency and medium frequency radio bands, invented by Harold H. So if I use a 21 meter long wire, I take a 10. The wire is then connected to the transmitting and receiving radio communication station. I first saw what I now call the 5 minute - $5 antenna mentioned on a QRP reflector by Peter Millis , M3KXZ. End Fed Antenna. Click on Calculate and the optimum length for that combination will be displayed in feet, inches and fractions of inches, and in meters. 5 metres long or 0. Use PVC couplers to allow yourself to go to one inch OD for the coil. The antenna wire is 26 AWG copper clad steel wire with a great "silky" jacket. For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun. If the wire is a harmonic length then it will be voltage fed and this is the type used in most base 11m verts, ie Antron, Sirio 827,imax and so on and on (they are all end fed wires). 1 MHz, 710 Ohm at 14. Ver2cal'Wire'Antenna' • Actually'a'ver2cally'orientated' resonate'1/2'wave'dipole'with' the'earth'being'the' return ' half' • Due'to'poor'ground' conduc2vity'a. This article will initially concentrate on the half wavelength of wire and its use as an effective multiband antenna. We've been in the radio business for over 15 years and sold hundreds of these antennas to satisfied hams. 4 of a wave length in length and spaced 3° is considered an excellent ground system and in case of high base voltage, a base. High power end-fed. There are two main benefits in using an end fed half wave antenna over a coax fed half wave dipole. The wire is more expensive than others but resists kinking and has a very rugged PVC coating. My antenna is 9. This method is often called the END-FEED or VOLTAGE-FEED method. End Fed Half Wave Antenna Coupler Schematic – 7-30MHz. GAP TITANDXVERTICAL 10,12,15,17,20,30,40,80 25FT 25LBS. connects to your tuner or rig with internal tuner using high. In my last post, I related the experience of making a segmented inverted v dipole antenna covering the 20, 15, and 10 meter bands. The antenna's length (approx. Let's talk about the EFHW (End-Fed Half-Wave) Antenna some more. A fund raising project by members of the Emergency Amateur Radio Club of Honolulu. NOTE 1: This original N2CX article was first published in the 72 newsletter back in 1997 or 1998. NOTE—The purpose of a counterpoise is to provide a relatively high capacitance and thus a relatively low impedance path to earth. Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. I've been a big fan of these lately, especially for QRP field ops. See full list on hamradio. 40m loaded dipole design. Multiband half wave end-fed HWEF (2012) Yes it's cheap, easy to build, doesn't need radials and it works GREAT! It sounds to good to be true. There are two main benefits in using an end fed half wave antenna over a coax fed half wave dipole. The first case involves a field antenna, either in the form of an inverted-L or in the form of a sloping wire. Text Questions to 513-868-6399: 800-221-7735. (Haven't tried it. GAP MONOGAP40, MONOGAP-40, MONOBAND 40m VERTICAL. Two required for dipole. The antenna is made of #14 plastic coated solid copper wire. BOW TIE ANTENNA: This is also referred to as a BUTTERFLY antenna because it has two symmetrical sides and is fed from the center. G5RV Multi-Band Antenna by Louis Varney,. A counterpoise – whether a length of wire or the outside of a coax shield- is highly recommended. Home; end fed antenna counterpoise length. Before I get into the nitty-gritty details, let me first make a distinction between end-fed half-wave antennas, such as the ones sold by LNR Precision and end-fed wires that use some kind of tuning to achieve a 50 Ω output impedance. Though a short conductor is shown to the right of the right hand feed line wire, the length is not specified or discussed in the accompanying text. Beverage antenna. Amateur Wire Antennas. The counterpoise wire is an important part of tuning the antenna. This may be achieved by utilizing an extensive earth-net or counterpoise respectively in order to cover all short wave bands. 5, but the bandwidth is narrower than the end fed. ADVANTAGES OF THIS J-POLE. The #26 black polyethylene jacketed Polystealth wire is light weight yet strong. Current Flow Fundamentals for an “End-Fed” Antenna – part 1. I also chose to use a counterpoise of 16 feet of Wireman 532. 7m wire had wider band width on 80m, but notice no better performance than 40m 20. Text Questions to 513-868-6399: 800-221-7735. Ideal for any kind of outdoor activity like SOTA, hiking, holidays, camping etc. The counterpoise can be anything, think of: a piece of wire, the zinc gutter, the antenna mast or a ground pin. While these lengths have been shown to work well on many bands, which is helpful if you're in a hurry to get on the air, read up on the topic and experiment. Random wire and long wire. Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. GAP MONOGAP20, MONOGAP-20, MONOBAND 20m VERTICAL. Figure 1 shows a typical example. Portable operation could not be easier. A friend of mine has a commercial antenna, which consists of a matching network, a trap and around 40 feet of wire. The antenna 200 made up of the poise 202 and the counterpoise 204 with a small gap between the two ellipses can be fed electromagnetically at this gap by a micro-strip 208 line that can come in at an edge of the substrate 206, at one end of the antenna 200, i. Antennas for 160 meters on a standard half acre (~100 x 200 ft) suburban house lot pose quite a problem. Figure 6 shows my NEC model for an inverted-L mounted along the top of a 6 ft high fence. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. 1), an end-fed half-wave antenna needs a 0. Length, Stainless Steel Hardware, SO-239 Connector, Each Not Yet Reviewed Part Number: PEZ-EF-15 More Detail. Something like the EARCHI end fed with the 9:1 balun. an end-fed antenna without equal current flowing into some form of counterpoise at the feed line or stub connection. Amateur Wire Antennas. ADVANTAGES OF THIS J-POLE. The antenna cannot be an actual 1/4 wave length on any ham band. The basic formula for determining the length of a center fed, half-wave wire Dipole or Inverted Vee antenna is:. In my experience, I normally use the half length of the antenna wire. Small enough to fit in your glove box or your bug-out bag. All DXTREME models are a different design that work most efficiently with the length of wire is sold with. G5RV Multi-Band Antenna by Louis Varney,. Both pieces of wire are attached via wing nuts to the Matchbox. With our W3EDP-derived end-fed zepp, the antenna will work satisfactorily on 40, 20, 15, and 10 meters. Two required for dipole. Generally the 9:1 has far more loss as the transformer/core takes on heat to make the non-resonant antenna be of any use across wide bandwidths and are. EndFedZ® Overview. makes the antenna less sensitive to ground type below the antenna and counterpoise height. MININEC predicts for the impedance of an end fed halfwave antenna versus the "counterpoise" length. Feeding an End Fed Half Wave Antenna ½ l •May work (somewhat) since the coax shield acts as a counterpoise: •Coax shield provides the return path for the RF field •Performance will vary with X, proximity to ground, etc •SWR losses on the coax can be a problem •Tuner needs to be at the base of the antenna X RF Field Tuner. One advantage of the end fed half wave antenna over an end fed "random" wire antenna is that it can be used on bands harmonically related to the band it is cut for without a tuner. length of Paracord to the Insulator (e) at the end of the Antenna Wire. GAP MONOGAP40, MONOGAP-40, MONOBAND 40m VERTICAL. Use PVC couplers to allow yourself to go to one inch OD for the coil. 7% similar) Grounding at the lug next to so239 connector is recommended. It can be easily attached to a window frame, window box or balcony railing. It also formed the basis of the antenna I finally decided to use. Here is an interesting quotation from Laport[14] regarding counterpoises:. I am wondering if anyone has found a "perfect length" for your end fed antenna so it can be used on multiple bands, for example 10-20-40. End-Fed Random Wire •Not resonant - covers all bands •9:1 Balun and tuner required 9:1 balun brings the 2000-5000 Ohms down to 250-600 Ohms Within the range of broad-band tuners (LDG, MFJ, etc) Most internal tuners are limited to ~25-150 Ohm tuning range WARNING ! Coax shield becomes the counterpoise Brings common mode RF current back to. It consists of an 85ft wire fed against a 17ft counterpoise. 50 feet long and consists of a 25 foot long matching section. Dual Band - $55. An end fed half-wave antenna would seem the ideal solution for portable operation. Just over 300 people responded. A close cousin to the random wire end-fed is the half-wave end-fed. 2 or lower on these bands. (There is a variant by OH5RM for low angle on 10MHz – see pdf doc) When compared to “straight up” vertical antennas, the combined horizontal and vertical components of the G7FEK antenna still give rise to useful high angle radiation. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. The EFHW transformer can be bypassed with this relay which turns the antenna into a 130' end fed. The W1SFR End Fed Antenna is 35′ long and made with 18 ga Davis RF "PolyStealth" antenna wire, or Wireman "silky" 18ga. A 30 foot 18 gauge antenna wire is included. In many cases, the impedance can be transformed with the help of a 9:1 unun (unbalanced input. Rechecked VSWR now ok @70mhz 1:1 @ 70. The reason is not complicated. It is also recommended that the parallel network tuner at the antenna end feed point be fed with a high quality run of Belden 9913/RG-8U or Belden 9258/RG-8X coax back to the radio shack. 5m) end-fed is insulated for safety. Additionally, a half wave does not require radials for proper performance. Random wire and long wire. ** If Step 1 length is too short or temporary lower frequency use is desired, add a stub at the balun. Multiband half wave end-fed HWEF (2012) Yes it's cheap, easy to build, doesn't need radials and it works GREAT! It sounds to good to be true. Thus 8, 16, 32, 68 lengths are ruled out. It also formed the basis of the antenna I finally decided to use. ADVANTAGES OF THIS J-POLE. 35m with 80m coil. It needs something to push against, a counterpoise. In theory the antenna end impedance should drop to about 1800 ohms. Some bands/frequencies you will have good efficiency others less, depending on your length of wire used and grounding system. 40/20/10m End-fed Antenna Rig Things to note: 1. Below is the schematic of the final build. The antenna consists of a short whip, tuneable coil and counterpoise - totalling 250cm in length. Technical Specs: Antenna Tuner; not Required. With this length of wire a coil of 11 turns is required, resonating the antenna on 1. The antenna was in my drive way in front of the garage that you see here. I have changed the counterpoise wire from 1. The matching section. Lets take 20 meters, 468/Frequency = Half wavelength: 468 / 14. For better effciency with the counterpoise, you can build or buy (the MFJ Artificial Ground) a counterpoise tuner. Off Center Fed Dipole Antenna For 40m, 20m, 10m, And 6m Model 40-6lpocfd. This is about 70 feet long and runs from the second floor window where the station is located down to a large tree in the back yard. We've been in the radio business for over 15 years and sold hundreds of these antennas to satisfied hams. Now remove the resistor and connect the antenna wire of aprox. Here's a great end-fed long wire 80 - 10 Meter multi-band antenna. Fishing bag 150mm Counterpoise (quarter wave length) Antenna tuner Feeder. I plan to use a 1/4 end-fed wire cut for the 20 meter band and also use a wire of the same length as a counterpoise for my RF ground (the other half of the antenna). End-Fed Half-Wave Antenna & Tuner. The end-fed Zepp was driven with tuned feed line sections, making it primarily a single-band antenna. This article will initially concentrate on the half wavelength of wire and its use as an effective multiband antenna. This is true with a quarter wave antenna, which needs an extensive ground plane. 5m) end-fed is insulated for safety. 35m wire with a 80m 40. NOTE—The purpose of a counterpoise is to provide a relatively high capacitance and thus a relatively low impedance path to earth. These dimensions were derived from modelling the antenna in EZNEC. It is used with radio transmitters or receivers when a normal earth ground cannot be used because of high soil resistance or when an antenna is mounted above ground level, for example, on a building. I use one, and it has helped my antenna efficiency a bit. Your complaints of RF in the shack are to be expected and tough to kill unless the system is set up properly. Text Questions to 513-868-6399: 800-221-7735. 5kw multi-band g5rv hf dipole antenna kit 5 out of 5 stars (9) 9 product ratings - JETSTREAM JTG5RV 10-80m 1. End fed antenna 9:1 UnUn. An antenna comprises a feed port, a 1/2 wavelength radiator (20), and a double resonant transformer (10). It consists of a 1/2 wavelength horizontal radiator wire connected to one conductor of a length of parallel 300 ohm or 450 ohm twin feeder, often quoted as being 1/4 wavelength long. If you intent to work the antenna as a multiband you will need to put a minimum of 3 counterpoise wires 1/4 wave on the lowest band. With multi-lobes come deep nulls in certain directions (diagram thanks to VK6YSF). The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. The design of the antenna allows it to be installed in many ways. It might seem that an "end-fed" is a monopole antenna: there is no explicit "counterpoise" in most end-fed designs. I called him at 2. It has a wide band and vertical polarization. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. " I think you might want a counterpoise for use on the WARC bands. The reason is not complicated. Use PVC couplers to allow yourself to go to one inch OD for the coil. A single non-resonant counterpoise wire with a length of 52 feet will provide satisfactory performance on all frequencies. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Also included is our new "counterpoise wire adapter", or "CWA", which connects to the side of the Versatee or the end of the standard coil when using the NVIS setups. In the case of an end-fed antenna fed with open-line, only one wire at the end of the feed line is connected to the half wave antenna. End Fed Half Wave Antenna, 21. Your feed line is essentially the counterpoise, so a separate one is not necessary if you want to keep weight. This creates a matched antenna, with a quarter. Some books say that you don’t use the counterpoise at all on 10m. Tokyo Ham Fair and Huntsville Hamfest- Kenwood TH-D74 Released D-Star Radio. [AA5TB] has a page that explains a bit about the. High power end-fed. Without an earth the antenna will try and use the coax as the return path. G5RV Multi-Band Antenna by Louis Varney,. An internal input-isolating current balun provides isolation of DC and RF grounds for optimum tuning of the RF counterpoise. 05 wavelengths at the lowest operating frequency. If you're only going to do 75m, like Jim said, 33 feet would electically give you (sort of) a 1/2 wave, off-center fed dipole. The #26 black polyethylene jacketed Polystealth wire is light weight yet strong. G7FEK Limited Space Antenna G7FEK Multi-band "Nested Marconi" Antenna - 2008 Version (rev 5) This antenna was first conceived as a simple dual band antenna in 1988, in an attempt to achieve sensible dual band operation in a small garden of 14m (46 ft) length. The feed, port, having a signal feed portion (34) and a ground portion (44), is at a low impedance while the 1/2 wavelength radiator (20) has opposed high impedance ends (21 and 22). In comparison with the dipole it does not need so much feeder and should be simple to set up. Counterpoise (ground system) The antenna is fed unbalanced. Current Flow Fundamentals for an "End-Fed" Antenna - part 1. Make sure to use fish line or other non conductive material for this purpose. Tuning range of the EFHW antenna is determined by wire length of the radiator. This worked much better and gave good results on all bands. They are not a half-wavelength long, meaning that, if you choose the length of the radiator wisely, the impedance at the end of the wire will not be as high as the impedance of a half wavelength long wire. Feed Point Impedance = F(height above RF ground, offset) Dipole Examples. Low angle is dominant on all bands expect 10 MHz, where the antenna is working as a end fed dipole. 4 of a wave length in length and spaced 3° is considered an excellent ground system and in case of high base voltage, a base. 05 wavelength on twenty meters it doesn’t,it seem to make any difference to the SWR or the current distribution along the length radiator. But if there is, some things can help. These dimensions were derived from modelling the antenna in EZNEC. From IEEE-145-1993-R2004…. Figure from Laport [14]. In comparison with the dipole it does not need so much feeder and should be simple to set up. Others say that you can use a 6. Also, without equal load impedances on each conductor, like a symmetrical dipole would have, it becomes impossible to have perfect feeder terminal voltage and current balance. All Band Single Wire Antenna,The Zeppelin. The where the included angle between arms is 90 degrees pointing Up and 90 degrees pointing Down. 80 through 10 meters is good, and the KX3 tuner will match it easily. The matcher box uses a T82-43 Fair-Rite core. MSRP: $44 including shipping. Evolving from a simple end-fed Marconi for 80m, the idea was to use the opposing. 5MHz), therefore it is also resonant on the second, third and fourth harmonics. GAP MONOGAP20, MONOGAP-20, MONOBAND 20m VERTICAL. A short wire is all that is needed: about 0. The antenna will be resonate at the Amateur bands specified for each model with very low to almost flat SWR. The design of the antenna allows it to be installed in many ways. In the end I decided to use a 57m (due to the position of supporting structures) long doublet fed with 450 ohm ladder line and connected to an auto-atu at the base of the antenna. Length of counterpoise should be a minimum of 20-30 feet but longer is better. 12), just like all antenna radiators. No counterpoise wire or ground is required, but it is suggested for best performance. In theory the antenna end impedance should drop to about 1800 ohms. No tuner required. These dimensions were derived from modelling the antenna in EZNEC. Text Questions to 513-868-6399: 800-221-7735. Page 2 MFJ-1625 Instruction Manual Window/Balcony Mount Antenna 2. Since my unit was to be used in the field I wanted the option to forego using coax cable altogether. You can make it work on any band with the right length of antenna wire. Improvising an End Fed Wire • Think about where most current will be – Current must be zero at an open circuit – Current will be max λ/4 (and 3λ/4) from an open circuit (low impedance, easier to match) • Could be closer if loading coils, capacitance – A high current point high and in the clear usually makes the antenna more efficient. I also chose to use a counterpoise of 16 feet of Wireman 532. The antenna is sported by a 22ft (6. Fig 3—An 80-meter half-square configured for 40-foot high supports. Here is the definition of “counterpoise” appearing in the Communications Standard. In my last post, I related the experience of making a segmented inverted v dipole antenna covering the 20, 15, and 10 meter bands. INterested in getting a different antenna build i stumbled on another forum i come on a new design of the old trusty end fed antenna, older as me, but not with a 1:9 balum but a new design 1:49 balun and resonant wire after that multi band. In this configuration, the coax shield will act as your counterpoise. The configuration for my EndFed antenna is the Balun end is in a tree about 25 feet high with the wire extending down to my shed and is terminated about 8 feet above the ground. Part 1 - A simple transmitter, transmission line, and an "End-Fed" antenna WITHOUT a formal "Counterpoise" - We will see why common-mode current must ALWAYS flow on the coax shield. In this configuration PAR End-fed half-wave antenna. If you intent to work the antenna as a multiband you will need to put a minimum of 3 counterpoise wires 1/4 wave on the lowest band. 20-30 feet but NOT resonant. A fund raising project by members of the Emergency Amateur Radio Club of Honolulu. The ULTIMAX DXTREME end-fed antenna covering 1. These antennas can be mounted horizontally, vertically or as a sloper. The Maple Leaf"QSO-KING" is an end fed, multiband, wire antenna that will cover all bands from160 to 6 meters, including the WARC Bands, as well as 60 metersandMARS frequencies. 5MHz), therefore it is also resonant on the second, third and fourth harmonics. I have never used one. Here is an interesting quotation from Laport[14] regarding counterpoises:. The end-fed random wire antenna has a 9:1 UNUN designed for use with radios that have an antenna tuner. 1 MHz, 710 Ohm at 14. Let’s talk about the EFHW (End-Fed Half-Wave) Antenna some more. The antenna tuner needs a 0. So now back to 40m 20. Divide 234 by the desired frequency (in MHz) to get the length. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. This article will initially concentrate on the half wavelength of wire and its use as an effective multiband antenna. Even though the WSPR mode is very efficient and claims a gain of +30dB compared to. They are not a half-wavelength long, meaning that, if you choose the length of the radiator wisely, the impedance at the end of the wire will not be as high as the impedance of a half wavelength long wire. Also included is our new "counterpoise wire adapter", or "CWA", which connects to the side of the Versatee or the end of the standard coil when using the NVIS setups. I first saw what I now call the 5 minute - $5 antenna mentioned on a QRP reflector by Peter Millis , M3KXZ. This suggestion is based on my understanding that only a very small counterpoise is needed with a true end-fed half wave, because the antenna is fed at a current minimum. BEVERAGE ANTENNA: This is a long wire horizontal antenna two or more wavelengths long with a 500 Ohm termination connected to a good counterpoise. This creates a matched antenna, with a quarter. Step#2 --- Attach one end of your coaxial cable to the special matching unit. As with most End-fed antennas an antenna tuner in needed and I have my new LDG AT200proII. 7MHz) or shortened (at 3. It’s exactly what it sounds like: a chunk of wire one-half of a wavelength long (in my case, 40 meters long so I can work. The coax feeder is the counterpoise! Power should therefore not be QRO – 25W max. So I produced a model using EZNEC which I based on a previous model of a ZS6BKW (G5RV variant) antenna I already had, complete with 450 ohm feed line. The antenna consists of a short whip, tuneable coil and counterpoise - totalling 250cm in length. wa7ark 3 What is an End Fed Half Wave Antenna? Let's call it a "EFHW" Works on a similar principle to a Zepp and J-Pole ~0. Now remove the resistor and connect the antenna wire of aprox. Portable End Fed Zepp. I started out with an end fed half wave - one wire cut for 40 meters and one wire cut for 20 meters. Here's a great end-fed long wire 80 - 10 Meter multi-band antenna. 47 RMS amps in this example. The End Fed Half Wave antenna (EFHW)for SOTA portable operation…from bits and pieces in the Junkbox… Whilst leisurely chasing activators this morning, I also took the opportunity to rummage through my Junkbox to see if I had all the bits and pieces to make an end fed half wave antenna for the 40M band. End Fed Wire Antenna. The antenna wire is 26 AWG copper clad steel wire with a great “silky” jacket. Here is the definition of “counterpoise” appearing in the Communications Standard. QRPGuys Portable No Tune End Fed Half Wave Antenna. I have one and the SWR is 1. Posted on August 31, 2014 by vk3yy. The far end of the antenna is about 6 feet above the ground. I also chose to use a counterpoise of 16 feet of Wireman 532. For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun. but Hams commonly call any end-fed wire a longwire or more correctly random wire antenna. END FED 6-40 Meter Multiband HF Antenna. 95 USD (2 offers) Princeton Antennas EF-53QRP 80 - 6 meter end fed wire antenna MADE IN USA! New. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. There are two main benefits in using an end fed half wave antenna over a coax fed half wave dipole. I'm quite impressed with it so far. The W3EDP 85 ft end-fed antenna - An 85ft wire fed against a 17ft counterpoise that works well in 80 and 40 meters [ Hits: 1893 | Votes: 2 | Rating: 9. The far end of the antenna is about 6 feet above the ground. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire. An end-fed zepp will work on its fundamental frequency and on odd and even harmonic frequencies (that is, where the flattop is an odd or even multiple of a half wave). Any 50 ohm coax feed line of 30 feet or more in length will work well. The antenna wire is 26 AWG copper clad steel wire with a great “silky” jacket. ) Their output coupling network is designed to efficiently handle higher impedance, optional end-fed antenna loads relative to the high plate impedance of a vacuum tube PA. Being an end-fed it does not really matter in which direction it goes in. If possible, run the counterpoise away from or perpendicular to the antenna wire. The VK4YE end fed antenna does need a small counterpoise of 0. They were asked to choose their ";favourite portable antenna" from: Ground-plane W3EDP Endfed Halfwave Single Band Dipole Random Length Endfed Doublet Linked Dipole Magnetic Loop Multiband Loaded Dipole Other The order the antennas were listed in was. Each wire assembly comes with 32' of insulated wire. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. input power: 50W up to 100W (depending on frequency) Length: min. This HF end fed antenna is broadband and covers frequencies between 3. This is about 70 feet long and runs from the second floor window where the station is located down to a large tree in the back yard. The optimum length of the counterpoise wire, as determined by extensive experimentation and mathematical analysis turns out to be approximately 0. A home brew 1 meter loop that is tunable on 40, 30 and 20 meters. same amount of current flowing into a ground or counterpoise of some type. It's a decent match on everything from 40m to 10m, but i was wondering about the effect of the length if the counterpoise. These dimensions were derived from modelling the antenna in EZNEC. You can even use a tuner to achieve a near perfect SWR on these bands, or an external tuner to. I had problems getting VSWR correct. Toss the wire up in a tree, run the coax on the ground (it also uses the coax shield as a counterpoise but isn't nearly as picky about length) and get on the air. Your feed line is essentially the counterpoise, so a separate one is not needed. The upside to EFHW antennas is no long counterpoise. The concept of end-fed halfwave has its detractors and proponents. This would require a 6:1 turns ratio. No ground plane or counterpoise is needed. This makes keeps the weight and bulk down while delivering a very strong antenna element. counterpoise needed per the instructions for the antenna. io Subject: [Elecraft-K3] K3 and end fed wire I am considering using my K3 on Field Day with an end fed wire. The antenna wire is 26 AWG copper clad steel wire with a great “silky” jacket. Below the result of a 30 minute daytime session on 40m in WSPR mode with 0. Since the antenna is end fed, we normally require an antenna tuner to match the impedance at the wire's end to the transceiver in use. 5ft counterpoise on 20m. Random wire and long wire. Being fed directly from one end and with, potentially, no need for a counterpoise the EFHW is as simple and as light as an aerial can get. Folding back the elements allows for the overall length to be adjusted shorter or longer as needed during the tuning process. maybe better. An earth on the Rig might upset the tuning. This is a not a major increase with this particular example of height and earth type, although there are cases where improvement can be greater. Horizontal Half Wave. Using the technique of your choice, support the other end from a tree or other tall support. The end fed half wave antenna can be operated with a small counterpoise, and in some instances, no counterpoise is used at all, although this is not necessarily wise. metal ground rod with wire. The coax feeder is the counterpoise! Power should therefore not be QRO – 25W max. I have inserted two additional links for coverage on 17m and 30m. The antenna wire is 26 AWG copper clad steel wire with a great "silky" jacket. I made a DIY antenna which I got a zap off the aluminium VFO knob - ouch !. Find Par EndFedz® Antennas with 40 meters Wire Antenna Band and get Free Shipping on Most Orders Over $99 at DX Engineering! Par EndFedz® Antennas are End Fed Half Wave (EFHW) antennas with the match box coax connection at the end of the wire, for convenient and quick stealth portable operations. N4KGL End Fed Antenna Configuration for Rapid Deployment. 8 metre counterpoise, this antenna is resonant in the 40/20/15/10m bands. The counterpoise can be anything, think of: a piece of wire, the zinc gutter, the antenna mast or a ground pin. 50 for the FL-259 soldered to the end of the Line). CENTER FED ANTENNA A Filed May 24,- 1945 IN V EN TOR. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0. 7m wire had wider band width on 80m, but notice no better performance than 40m 20. 50 feet long and consists of a 25 foot long matching section. If possible, run the counterpoise away from or perpendicular to the antenna wire. The coax will be about 23 cm in total resulting in 22pF. Amateur Wire Antennas. I have studied the information from Wayne N6KR as well as looked at other information on this topic on line. END FED 6-40 Meter Multiband HF Antenna Introduction This project produces an inexpensive, multiband, end fed HF antenna matchbox that is quick and easy to setup and use. Here's a great end-fed long wire 80 - 10 Meter multi-band antenna. These dimensions were derived from modelling the antenna in EZNEC. The antenna wire is then typically take out of the radio room, or shack and taken to a horizontal section that runs above obstructions. ( 14 customer reviews) £ 62. The end fed wire antenna simply consists of a length of wire that is as high and reasonably long as possible. The configuration for my EndFed antenna is the Balun end is in a tree about 25 feet high with the wire extending down to my shed and is terminated about 8 feet above the ground. male banana plug or PL-259 connector. Tune for minimum. elevated system called a "counterpoise" or "capacitive ground", with dimensions significantly smaller than λ/4, could be quite efficient. If possible, run the counterpoise away from or perpendicular to the antenna wire. Then you drive your vehicle ONTO the opposite end of board to hold it in place - drop your Buddistick or Buddipole mast into the pipe and you're ready to start operating. Maximum power is 75 Watts SSB on 80 meters and 100 Watts SSB on 40 through 6 meters. The antenna wire is 26 AWG copper clad steel wire with a great "silky" jacket. 4 lbs, the Model 418 will operate from any 13. Tuning range of the EFHW antenna is determined by wire length of the radiator. (120 radials of 0. (Counterpoise) In the case of the End Fed antenna, you can simply make an extra connection and connect it to the coaxial cable shield. The antenna required some adjustment, particularly in the 20 meter segment, which was cut a bit short. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. BEVERAGE ANTENNA: This is a long wire horizontal antenna two or more wavelengths long with a 500 Ohm termination connected to a good counterpoise. MININEC predicts for the impedance of an end fed halfwave antenna versus the "counterpoise" length. EOC HF ANTENNA: Vertical Jetstream JVT-680, 24-foot antenna, 125 watt KX4Z personal antenna Sloping dipole non resonant, from approximately 45 feet to approximately 15 feet, fed by manual antenna tuner. To operate on any HF band you need a wide range tuner like the internal. Optional tuning stub ** Coax feeder. 35m wire with a 80m 40. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. The coax feeder is the counterpoise! Power should therefore not be QRO – 25W max. Technically a true "longwire" needs to be at least one wavelength long. For operation, each side of the antenna is unwound to the label indicating the frequency required. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire. 5' for 20m). I also chose to use a counterpoise of 16 feet of Wireman 532. 5 MHz) therefore also resonant on second, third and fourth harmonics etc. Components of a End Fed Half Wave Antenna ••Radiator length is 1/2Radiator length is 1/2 λoftheoperatingfrequencyof the operating frequency. The following graph shows the performance of various antennas relative to a reference antenna consisting of a 10m vertical connected to an auto-tuner at the base of the antenna and fed against 10 random length buried radials. 3 MHz the distance in. Antenna Project - HF QRP End Fed Half Wave. 25, which equals 16. This is the feed impedance and SWR of an end fed 80 meter half wave with an ideal 49:1 transformer and good stable counterpoise or ground. Portable operation could not be easier. G5RV Multi-Band Antenna by Louis Varney,. That's a lot of wire at, say, 3. As long as you are feeding the wire in 1/2 wavelength multiples you don't need ground radials or a counterpoise. Each wire assembly comes with 32' of insulated wire. An end-fed zepp will work on its fundamental frequency and on odd and even harmonic frequencies (that is, where the flattop is an odd or even multiple of a half wave). Three turn primary from the radio and 24 turn secondary with a capacitor across it. Counter to tuning a length of wire like you would with a dipole, with a random wire you don't. 132ft inverted L. The article End fed Zepp showed the current distribution that exists for some different common feed arrangements. Total Length is ½ wavelength =468/F(MHz) Center Fed (50%/50%), Z=25-100Ω. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. the antenna 200 can be end-fed. This antenna has been made popular by the Emergency Amateur Radio Club of Hawaii (EARCHI). In it's simplest form you can use a random length piece of wire, at least 1/4 wavelength of your operating frequency, and throw it up into a tree. Return loss tops out at about 8dB. The end fed feature adds convenience, but does present another issue. Now remove the resistor and connect the antenna wire of aprox. A QRPGuys based "random" wire end fed with 29 and 35 ft elements. Additionally, a half wave does not require radials for proper performance. 3 MHz the distance in. or so I thought. 5 Wave-Length wire on lowest band (130ft on 80m, 67ft on 40m) Fed from one end using a transformer in a box. maybe better. The coax feedline between the EFHW tuner and the radio is 2 metres long. Portable operation could not be easier. It has become nearly as popular as the famous G5RV after all! It gives full HF coverage with no tuner needed on most frequencies, you do not need a long counterpoise, radials or feedline, it has a rugged weather-resistant 50 Ohm matching network, it is a super fast set-up and. 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. I have seen a measurement on the Dutch end fed with an antenna analyzer. End Fed Counterpoise QRZ Forums. No ground plane or counterpoise is needed. It consists of an 85ft wire fed against a 17ft counterpoise (attached to the earth point on the ATU). Pete called it the "No Counterpoise" antenna, and he's done considerable EZ-NEC work on it. 05 wavelengths long at the lowest operating. long and is mounted on a 12.