Counterpoise Length For End Fed Antenna









Full size version with wire length 41m. Click on Calculate and the optimum length for that combination will be displayed in feet, inches and fractions of inches, and in meters. Attach one end of your antenna wire to one of the binding posts, either directly or using a jumper wire. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. On the receive side, the standard 160 meter antenna is a Beverage of some form. 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. So if I use a 21 meter long wire, I take a 10. Ultra light, only 260 gram, end fed wire antenna for 3 shortwave bands 40m + 20m + 10m. The first 6ft (1. Priority Date: 06/23/2004. Your radio may be rated for 5 watts, but you’d be lucky to have a third of that power radiate from the antenna. However, the antenna does present a true half-wave or multiple of a half-wave on 17 or 12m, and so I suggested that OP might want to try a counterpoise to see if it helped with return losses on those bands. A 1/4 wave wire cut to length is an acceptable substitute. Antenna tuners are generally located at the trans-mitter output, at the radio end of the coaxial feed line. Each counterpoise was "tuned" to length by adjusting for maximum current in the countepoise for that band. (Counterpoise) In the case of the End Fed antenna, you can simply make an extra connection and connect it to the coaxial cable shield. 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. For those of us wanting to get moving quickly on this will notice that Mike wrote that a standard recommendation (see QST, March 1936, p. Figure 6 - SWR vs "Counterpoise" Length vs Turns Ratio for an End Fed Half Wave Free Space Antenna. I've built a 2 meter ground plane antenna that works pretty well for RX and has a decent SWR on 2 meters with my Alinco. We strung it in the trees of the campsite, fed-end high with a 60 foot RG58 feed, 45 degree of slope with 35 feet of wire. Many compromise antennas are the 6 to 12 foot variety. End Fed Half Wave Antenna, 40/20/10 meters, QRP, 25W CW/SSB, 41 ft. 5MHz) therefore also resonant on second, third, and fourth harmonics, etc. That’s a lot of wire at, say, 3. End caps were glued on. Full size version with wire length 41m. the usually high and complex impedance of an end-fed antenna system appearing at the receiver end of the coax, and the receiver's low impedance (50 ohms) at the SO-239 coaxial connector,. New style resonant end fed antenna requires no counterpoise. You would eliminate a source of unwanted interference: the "floating coax shield". A simple transmitter, transmission line, and an “End-Fed” antenna WITHOUT a formal “Counterpoise” – We add a loss-less choke at the feedpoint, tune out it’s inductance with a capacitor, and see why common-mode current on the coax shield is the SAME as without the choke. "Dublet" was the common name for this antenna when it was not a half. End Fed Halfwave. After much deliberating, I decided to go with an L-Match tuner and an End Fed Half Wave antenna, although it has morphed into something that is definitely end fed, but not exactly half wave. Then have different wire lengths to get to that "magical" halfwave length wire on each band. Primary Antenna Quarter Wave 40M end fed antenna. I tried to build a multiband EFHW antenna as described in articles by PA3HHO, PD7MMA, G0KYA and many others. Fast Setup and. The EFHW antenna is a popular choice among VK SOTA activators. 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. (3) The antenna ends may be attached various ways (refer to figures 1 - 3). The 1:9 ratio is typical for this kind of antenna, though one can vary this slightly if necessary. Counterpoise can be in the same plane as the antenna (i. It does not need to be straight. Chameleon Antenna is proudly manufacturing antennas that are 100% made in the USA. Nevertheless, I will also describe, how it is designed, if one decides to embark on building it for different bands. Tune for minimum. Mark pa1ssb made a qro 80 meter end fed antenna with a counterpoise. As the feed point moves towards one end, the impedance gradually increases to 2kΩ or more. The end fed antenna system works well in horizontal, sloper, and vertical configurations. To make the best use of an End-Fed antenna, it should be fed with a transformer. Ideal for camping, weekends away, holidays etc. 5ft counterpoise on 20m. The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. The black dots represent exact harmonics of the 3. This antenna has been made popular by the Emergency Amateur Radio Club of Hawaii (EARCHI). If you don't specifically provide one then the coax shield will act as the counterpoise. Tuning end fed antennas Hi, I have been experimenting with end fed antennas, but for me they always need quite a high capacitor to tune them (150+pF) A friend of mine also is working with them, but he seems to need much lower capacitors (10-20pF) and uses beehive capacitors, he gave me one, but it has a too small capacitance for my antennas. This calculator will help you to calculate the different wavelength of antennas based on the frequency. In this configuration the coax shield will act as your counterpoise. If you are only interested in operating 40 through 10 meters, you can try 36, 44, or 49 feet. 0 drops you to around 13. With the end-fed half wave version of the “Mini” and about 31′ of wire, we can get a 1. Commercially made portable antennas do work if you can afford them. Plans for the Antenna are available from EARCHI’s website Counterpoise lengths appear to be quarter the lowest band so for 160m will be 40m. 5' for 20m). One of the cautions you sometimes see in discussions of the end-fed antenna are "avoid multiples of a half wave. My antenna is NOT an end fed Dipole. 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. In designing a counterpoise for a medium-wave radio station, for example, radio-waves are a maximum of 566 metres (1,857 ft) long. The counterpoise to the antenna is the Earth itself. 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. I setup to use both the dipole and the Par Matchbox at the end of the 25 foot length of RG 174 I used three supports on each so they are deployed in a similar fashion. 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. Our showroom facility is a focal point for the local amateur radio community. I have the ladder line end of the W3EDP hung up a tree in the back garden with the copper wire over the roof of the house and tied off at the gutter at the front, so it’s not particularly high. Cul = transformer wire. As in any vertical type antenna, a ground radial system or counterpoise is essential for maximum results. The antenna came into my 2nd-floor room window where I fed it via a tunable LC network, tuning the L and C to match 50 ohms into the. It may load up nicely, but so does a dummy load. Feeding and matching is simple; it's fed with a quarter-wavelength of RG-11 or RG-59 (75 Ohm) coax, and then any length of 50 Ohm coax. The vertical end fed half wave antenna is my choice for it’s easy to employ and it's a perfect DX antenna. Shorter length counterpoise wires can be used of operation is confined to 40m or higher. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. Attach one end of your antenna wire to one of the binding posts, either directly or using a jumper wire. Some words of caution are in order, however, if you plan to use your rainspout as an antenna:. 5' for 20m). The usual way of feeding an end fed half wave is against a short counterpoise, but I have found that with QRP you can feed this one without an earth stake, counterpoise, or radials. " 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. You do NOT need an additional counterpoise or ground wire with this antenna. Throw out the coax length, and use an abritrary length - say 14 feet. Being able to feed the dipole from one end gives you more options on how to erect an antenna and makes portable operation easier. New style resonant end fed antenna requires no counterpoise. There's many info in the internet, Google is your friend HI. Of course, I calculate basic stuff, length etc. A standard recommendation (see QST, March 1936, p. type of antenna used to be called an end-fed Zepp. Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired. I've just built an end-fed wire antenna and am using a 9:1 unun to feed it. Counterpoise. Posts: 58 The W3EDP antenna (pic attached) seems a popular length of end-fed antenna, being 25. Length is not critical, but best longer than 50 feet. At zero counterpoise length, impedance is infinite and no current can flow,  necessarily meaning that all working “end-feds” have a counterpoise of some sort, whether formally designed into the system or no t. It is a resonant Half wave on 40m (7MHz) therefore also resonant on second, third and fourth harmonics, 20m (14MHz), 15m (21MHz) and 10m (28MHz). •Need lots of room, keep. End caps were glued on. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. 45e-6) SY EndHeight=1. Repeat the experiments above with the EARCHI end fed matchbox for comparisons. Throw out the coax length, and use an abritrary length - say 14 feet. If using coax in this manner, does the coax need. Any length of wire has a resonant frequency. Installation Notes There are several methods of installing the antenna and some are better than. 20-30 feet but NOT resonant. Chameleon Antenna is proudly manufacturing antennas that are 100% made in the USA. Communications fall into one of two categories: Line of Sight(LOS) and Beyond Line of Sight. Jack greatly enjoyed big 160 meter transmit and. Ideal for camping, weekends away, holidays etc. Using the 12’ shock cord whip, two 22” arms and the TRSB set at 4:1. This is purely unintentional as I had made that wire at least a month or two before I ever knew about the aftermarket antennas. Last up was the 20m antenna. I have one question, build an antenna for cb 27Mhz vertical dipole. 57 MHz fundamental resonance. 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 simulations were performed for ideal (lossless) antenna elements with a diameter of 1. Current wants to flow into a low impedance. CM End fed multi-band using a single coil to adjust resonance CM CE SY L1=2. Recommended wire lengths and Installation Notes for Unun models 4932, 4935, 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. Our showroom facility is a focal point for the local amateur radio community. All DXTREME models are a different design that work most efficiently with the length of wire is sold with. 950MHz with an SWR of 1. The near end connects to a matching unit situated in the loft of the house. Review (mpn: EF-53 for sale) EF-53 PRINCETON Meter Fed ANTENNAS Antenna Wire 80 6. 2/ I also want to make a multi band portable aerial for HF, as portable as possible. 10-80 meter ProMaster HF antenna, 160M* optional. A random wire antenna is a radio antenna consisting of a long wire suspended above the ground, whose length does not bear a relation to the wavelength of the radio waves used, but is typically chosen more for convenience. It is important to use a counterpoise. Rma required to return an item. Some books say that you don’t use the counterpoise at all on 10m. It consists of 30ft (10m) of wire fed into a 9:1 UnUn (Unbalanced to Unbalanced). 5′ long counterpoise. Evolving from a simple end-fed Marconi for 80m, the idea was to use the opposing. All coax runs through window next to mast. Communications fall into one of two categories: Line of Sight(LOS) and Beyond Line of Sight. In the case of the end fed random wire, some lengths are better than others because of the har-monic effect of the length of the wire and how that effects the various bands on which you wish to operate. That's a lot of wire at, say, 3. In designing a counterpoise for a medium-wave radio station, for example, radio-waves are a maximum of 566 metres (1,857 ft) long. But you have to include the lengths of both the "intended" radiator (wire antenna) and the counterpoise or ground system, as they're both active radiators and if they're different lengths, you have an "off. The length of the counterpoise is not critical. With this in mind, I purchased 9:1 UN UN from Balun Designs and ran another end-fed this time with a wire length of 52 1⁄2 feet, again from the palm tree but to a different corner of the house, then a 100 feet of RG-8X from the UN UN to. The antenna, containing the poise 103 and the counterpoise 104 can have a small gap G 2 between the two ellipses, can be fed electromagnetically at this gap by a micro-strip line 108 that can come in at an edge of the substrate 106 at one end of the antenna 100, i. MEF-107-3K Multi-Band End Fed Half Wave Antenna Transformer Now you can make your dream low band antenna with just 259feet of wire (~79m) and operate on five bands without use of tuner at legal power using as much as 3kW ICAS. Full Wave Loop Antenna. connected to the ground lug on the network of the antenna and you're ready to go. Wire type: Copper stranded Color: Grey or Black depending in stock. These fed into a small matching box that I built using a schematic I found online. SWR will vary based on topography, proximity of nearby structures, configuration of the antenna wire and choice of ground or counterpoise. 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. The counterpoise can be anything, think of: a piece of wire, the zinc gutter, the antenna mast or a ground pin. This means that the antenna will always have a feedpoint impedence appreciably higher than 50 ohms and will not require much of a ground system to perform adequately. As others have stated, your coax is the other half of the antenna, and sometimes the 9:1 unun setup can be helped out with an extra counterpoise wire. 160 Meter Folded Counterpoise Inverted L Antenna - Duration: 18:21. The coax feedline can also serve as a counterpoise but I read varying reports of improved results with a wire counterpoise so I choose to experiment with and without one. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. I've built a 2 meter ground plane antenna that works pretty well for RX and has a decent SWR on 2 meters with my Alinco. 5 metres to 6. 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. A 160-meter system might require 16 feet of counterpoise height, and that will directly subtract from effective radiator height. The end fed antenna system works well in horizontal, sloper, and vertical configurations. Years ago the end fed antenna was the most popular HF antenna type used by radio amateurs. Do You Need A Counterpoise Wire? I find a counterpoise about 17 feet long works well if I want to get on 40 meters. The end fed 1/2 wave antenna, much like the 43 foot vertical, has become a cult phenomena. The simplest method of feeding energy to the half-wave antenna is to connect one end through a capacitor to the final output stage of the transmitter. If you want to use the antenna for 80m, the you will need to add a counterpoise, and I suggest using an additional 50 to 100′ of wire. But you will introduce another potential source of. Rma required to return an item. The simulations were performed for ideal (lossless) antenna elements with a diameter of 1. For better effciency with the counterpoise, you can build or buy (the MFJ Artificial Ground) a counterpoise tuner. Since the full-length W3EDP can readily tune 6m - 160m, its half-size version would likely tune up to 80m. Note the lack of counterpoise of other ground connections. The insulator next to the house can be a plastic or n ylon pulle while the one at the tree could be made from a piece of plastic pipe. Hi, I am interested in end fed aerials. Keep in mind that every end fed / vertical needs some kind of counterpoise to push against and in this case that's the coax , so don't forget a line choke near to your transceiver. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. Link End Fed Half Wave Antenna and Tuner for SOTA. Then riveted. This discovery made me take another look at the design of J Pole and End fed Zepp antennas. No counterpoise needed but grounding is recommended on permanent installations. It is fed by an trivially small transmitter at the base of the vertical section using an ideal current balun. The feed line acted as a matching section for the transmitter. However, I'm experimenting with SDR quite a bit and would really like to bu. Option Two: Another stopgap measure would be to replace the coax with a length of insulated copper wire, connected to the Hi-Z terminal on the back panel of the FRG-8800. Performance on 70cm is good too - though being a 3 ⁄ 4 wave there’s no huge advantage to the length. ***We make this same antenna design in many different lengths. The end-fed feature adds convenience, and makes it very portable. Length: 60' Weight: 1. The Vibroplex PAR EndFedz® are a full length half wave dipoles, but with an important difference. Counter to tuning a length of wire like you would with a dipole, with a random wire you don't. Therefore, the counterpoise should extend 282 metres (925 ft) from the. Now on to testing the both end fed antennas. Place a 1:1 Balun on the Antenna end of the Feedline. Wideband Dipole for Receiving 16 24. Antenna (Counterpoise) Ground is the other half of the antenna. 18m with spacers to make it ladder line, but we digress. Note the 20 meter length of wire is connected to the earth side of the capacitor – make that the rotor then the control shaft is also at earth potential so there is no chance of getting a RF burn while tuning. Rma required to return an item. The Par End-Fedz ® are a full length half wave dipoles, but with an important difference. The antenna current at midpoint was 210 ma. It is inversely proportional to the frequency which means the wave with higher frequency will have shorter wavelength. Since 35 feet of antenna length represents a near halfwave length on 20m, you may be able to devise an impedance matching device to match to the high input impedance such as an end fed half wave tuner on 20m. Remember that the antenna tuner wants to match the antenna and transfer as much RF energy to it as possible. 5 Wave-Length wire on lowest band (130ft on 80m, 67ft on 40m) Fed from one end using a transformer in a box. The other end of the antenna was. The UNUN transformer and connecting. 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. Since 35 feet of antenna length represents a near halfwave length on 20m, you may be able to devise an impedance matching device to match to the high input impedance such as an end fed half wave tuner on 20m. Simply type --- end fed antenna ---- into the search box and it will take you to all of our "QSO-KING" models. Resonant on specified bands, no tuner needed!. The length of the counterpoise depends on the antenna wire or. 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). The finished End Fed Half Wave antenna coupler. Some books say that you don’t use the counterpoise at all on 10m. The antenna is sported by a 22ft (6. Note that any of these lengths are going to be long on 6 meters. Both can be used on multiple bands though the random length one may have a slight advantage there if you. Current along the half wave. Every antenna is about balance & half the antenna is the radiator & half the antenna is the counterpoise & if that counterpoise does not exist in a transmitters antenna, then the coax is used as part of the antenna system & that is why some fools think an end fed antenna needs a choke at it's. You can experiment with different lengths. The feed through insulators allow the antenna and counterpoise wires to exit the house. Above applies when in free space. Yes, a giant yagi antenna on a tower would be ideal, but you said you wanted cheap. An L-match and 30 metres of wire should be fine as an end-fed half wavelength. DERIVATIVES. Questions: 1. 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,. That is the LNR end fed dipole which is for specific bands, ie. The wire may be straight or it may be strung back and forth between trees or walls just to get enough wire into the air; this type of antenna sometimes is called a zig-zag. Terminology. So if I use a 21 meter long wire, I take a 10. The end fed 1/2 wave antenna, much like the 43 foot vertical, has become a cult phenomena. The Zeppelin Antenna. I have the current Rybakov antenna setup as a baseline. RHF wrote: > For the Shortwave Listener's (SWLs) Inverted "L" Antenna > the "Work-Around-Center" is the BASE of the Vertical Up-Leg. Some words of caution are in order, however, if you plan to use your rainspout as an antenna:. I use one, and it has helped my antenna efficiency a bit. endfed antenna by many radio amateurs over a long period, but it was more or less forgotten when most radio amateurs started using coax-fed dipoles. Displacement is the term used for the distance between the counterpoise (which is the antenna system's lowest element) and the ground. 100% Copper, 16 Gauge, 26 Strand Wire, UV Protective Coating. 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. This configuration is terribly inefficient because the antenna is a fraction of a wavelength it should be. For those of us wanting to get moving quickly on this will notice that Mike wrote that a standard recommendation (see QST, March 1936, p. If you add the length of the original G5RV to the feeder described and take a velocity factor of roughly 90% into account, the full electrical length from antenna tuner to the end of the antenna is about 27 metres. I've brought this up enough times already; let's de-mystify this beast. 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. Make this from a piece (19. (A common configuration seems to be to run the counterpoise parallel to the main wire for its first 5. The length of the counterpoise is not critical. A 14 meters ( 46 ft ) multi band antenna for small gardens that works well on 80 meters Main bands (@~50 ohm) are 80m / 40m / 30m / 17m / 15m / 12m Evolving from a simple end-fed Marconi for 80m, this antenna design was created by Mike G7FEK (reproduced with consent ). Usually it is a simply a Dipole, fed in the middle with openwire feedline. The far end of the antenna is about 6 feet above the ground. 5 to 28 MHz HF bands. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. Extremely Lightweight. 5MHz) therefore also resonant on second, third, and fourth harmonics, etc. An earth on the Rig might upset the tuning. Throw out the coax length, and use an abritrary length - say 14 feet. 20-30 feet but NOT resonant. 5 MHz, but you can loop the wire around the room and hide it from view. 6-80 Meter BASIC-FMJ portable HF antenna. Due High Impedance feed point, the antenna is less. a monopole antenna one- quarter wavelength long, mounted vertically with the lower end either connected directly to the ground or grounded through the antenna coupling network counterpoise wire structure placed below the antenna and erected above the ground and it should be insulated from the earth ground. 05 m counterpoise), but some other articles say that I need "a good RF ground in close proximity to the end of the antenna". I also chose to use a counterpoise of 16 feet of Wireman 532. Some words of caution are in order, however, if you plan to use your rainspout as an antenna:. Not bad for a relatively small antenna. Ideal for camping, weekends away, holidays etc. The ATU can be either preset or automatic and may require a control cable in addition to the coaxial cable feeder 15. I messed around with this quite a bit but I couldn't find a good length of antenna wire and feeder which made a significant improvement over the 'normal' sized version. South end I have a mast ~ 12' above roof and a Diamond X300 at top. radiator and the 13-ft. Your radio may be rated for 5 watts, but you’d be lucky to have a third of that power radiate from the antenna. 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. The problem with an end fed half wave antenna is that the antenna presents a high impedance, creating a. MY FINAL SET-UP: I started my experiments with. Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. That is the LNR end fed dipole which is for specific bands, ie. How to create a counterpoise for an EFHW antenna is hotly debated. 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. Right Angle Marconi Antenna 17 26. 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. The recommended antenna wire length is 30 feet. Assuming the other wingnut is connected to ground, an extra length of wire as a counterpoise would probably help. The MyAntenna 8010 End Fed is an End-Fed Half-Wave (EFHW*) antenna. that I have yet to find another experimental indoor antenna that can beat it, including magnetic loops, crossed field loops and EH antennas. There's many info in the internet, Google is your friend HI. A definite must have accessory for radio amateurs using random length or inverted L antennas. It is designed to be non-resonant. A counterpoise is simply a length of wire laid on the ground and connected to the earth connection on the Paraset. The Hertz antenna is an antenna with an electrical length of a half wavelength at its resonant frequency. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. The first 6ft (1. Portable operation could not be easier. That length of wire is getting a bit long for a single 8 or 9 metre pole (it will sag) so find somewhere where there's a tree to hold it up at the other end. SOTAbeams Half-Wave End-Fed Portable Antennas are half-wave end-fed antennas for hams on the move. Figure 6 - SWR vs "Counterpoise" Length vs Turns Ratio for an End Fed Half Wave Free Space Antenna. In the antenna current diagram (top) there is a simulated counterpoise and small. com Here's a compact Top Band antenna system that actually plays with the big boys — no kidding! Let's begin at WØUCE's original 6 acre site in North Raleigh, North Carolina. Next, create the counterpoise. Tuning end fed antennas Hi, I have been experimenting with end fed antennas, but for me they always need quite a high capacitor to tune them (150+pF) A friend of mine also is working with them, but he seems to need much lower capacitors (10-20pF) and uses beehive capacitors, he gave me one, but it has a too small capacitance for my antennas. length dependent. (Counterpoise) In the case of the End Fed antenna, you can simply make an extra connection and connect it to the coaxial cable shield. Dropping the ability to tune in 160m seems an acceptable trade-off for the advantage of having a shorter multiband end-fed antenna with no counterpoise cables on the ground. It is fed by an trivially small transmitter at the base of the vertical section using an ideal current balun. Questions;. End Fed Half Wave (6. Some books say that you don’t use the counterpoise at all on 10m. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. Full size version with wire length 41m. 3:1 or better on all bands. All on one end fed wire. ; Fast Setup and takedown. Now on to testing the both end fed antennas. The distance between one point to another adjacent point in a wave is known as the wavelength. the usually high and complex impedance of an end-fed antenna system appearing at the receiver end of the coax, and the receiver's low impedance (50 ohms) at the SO-239 coaxial connector,. A definite must have accessory for radio amateurs using random length or inverted L antennas. Length of counterpoise should be approx. php on line 118. An end fed antenna whether random or resonant can be set up in various configurations such as a sloper, a vertical, inverted L, etc. l Basic formula for overall length of wire (both pieces) is L=468/f(MHz) (so at 14. 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). The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. The Hertz antenna is an antenna with an electrical length of a half wavelength at its resonant frequency. This antenna build was strongly inspired by the well known PAR end fed antenna. Assuming the other wingnut is connected to ground, an extra length of wire as a counterpoise would probably help. Above is the model topology. The need for expanding an End-Fed with such a "counterpoise" wire was already recognized well over a century ago!. I'm quite impressed with it so far. 2 enD-FeD AntennAS Another common antenna system for multiband opera-tion is the end-fed Zepp antenna shown in Figure 10. 5 metres long or 0. which was a 10m long vertical wire, fed against 10 random length buried radials and matched with the same auto-tuner that was used for the 'no counterpoise' antenna. A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. Not bad for a relatively small antenna. This antenna is a full wavelength single-delta-loop, with the point of the triangle at the top of the single support pole, and fed near one of the corners - One Quarter Wavelength down the diagonal leg. Simply hang the far end from a. The recommended antenna wire length is 30 feet. The End-fed antenna with a 1:64 Matching Auto Transformer is well worth building. 05 lambda counterpoise to work correctly. (For 20 meters) The length of 468/14. Then have different wire lengths to get to that "magical" halfwave length wire on each band. 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 coax feedline can also serve as a counterpoise but I read varying reports of improved results with a wire counterpoise so I choose to experiment with and without one. Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. Current wants to flow into a low impedance. 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. The black dots represent exact harmonics of the 3. Posts: 58 The W3EDP antenna (pic attached) seems a popular length of end-fed antenna, being 25. A 1/2-wave end-fed is also resonant and high-Z (radiation resistance, without any reactance). The antenna, containing the poise 103 and the counterpoise 104 can have a small gap G 2 between the two ellipses, can be fed electromagnetically at this gap by a micro-strip line 108 that can come in at an edge of the substrate 106 at one end of the antenna 100, i. In the largest part on a HF receive antenna the balun is there to provide electrical isolation between antenna & radio. Here are some photos of one of my 9:1 baluns. A simple transmitter, transmission line, and an "End-Fed" antenna WITHOUT a formal "Counterpoise" - We add a loss-less choke at the feedpoint, tune out it's inductance with a capacitor, and see why common-mode current on the coax shield is the SAME as without the choke. 8m) of 100ft (30. This project produces an inexpensive, multiband, end fed HF antenna matchbox that is quick and easy to setup and use. It is important to use a counterpoise. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. End fed 5 band wire antenna for 80m, 40m, 20m,15m, 10m, short version with wire length 23m. Length of counterpoise should be approx. The raw End-Fed antenna will go through impedance swings as high as 5K Ohms, or more, at even. This is the ideal antenna for FM operation on 6 meter, 2 meter, and 70cm bands. FEEDING AN ANTENNA AT ONE END The theoretical impedance of a center fed dipole antenna far removed from ground effects is around 73Ω. 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). 5″ for 220 and 6. Pete called it the "No Counterpoise" antenna, and he's done considerable EZ-NEC work on it. Established in 2008, Chameleon Antenna has been a great source of enjoyment for amateur radio operators. It does not have to be the exact same size as the antenna, although it helps if it is. It is essentially a vertical dipole, in which one side of the dipole is the RF image of the antenna in the ground. If possible run the counterpoise away from or perpendicular to the antenna wire. 66' Length. This is purely unintentional as I had made that wire at least a month or two before I ever knew about the aftermarket antennas. With this length of wire a coil of 11 turns is required, resonating the antenna on 1. "EFHW" - the end-fed half wave antenna. 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. New style resonant end fed antenna requires no counterpoise. 5", NA771 is 15. It has been compared with the following: • 85ft W3EDP end-fed that went up to the top of a 60ft oak tree in my garden with a 17ft counterpoise - the multi-band dipole beats it hands. According to some sources (ref. 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. Normally a wire, one-quarter wavelength long. a monopole antenna one- quarter wavelength long, mounted vertically with the lower end either connected directly to the ground or grounded through the antenna coupling network counterpoise wire structure placed below the antenna and erected above the ground and it should be insulated from the earth ground. But you have to include the lengths of both the "intended" radiator (wire antenna) and the counterpoise or ground system, as they're both active radiators and if they're different lengths, you have an "off. 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. When buried in the ground, its effective length changes a lot. End fed 5 band wire antenna for 80m, 40m, 20m,15m, 10m, short version with wire length 23m. Low angle is dominant on all bands expect 10 MHz, where the antenna is working as a end fed dipole. Ideal for camping, weekends away, holidays etc. Question I have is about the coax. I have NO rf in the shack. Current wants to flow into a low impedance. If possible, run the counterpoise away from or perpendicular to the antenna wire. S Stainless Steel hardware Stealth Marine #18 AWG. Length of counterpoise should be approx. A ¼ wavelength of transmission line is use to transform the Hi Z of the antenna to Lo Z for the transmitter. A quarter wave antenna really NEEDS a ground plane to work. Antenna Alchemy - End Fed Half Wave Antenna and The Way of the Goat I was a bit confused about the difference between a random length end-fed, and the EFHW. The end-fed random wire antenna has a 9:1 UNUN designed for use with radios that have an antenna tuner. The key to the antenna's success is a 9:1 UNUN, an antenna "tuner", and a good ground or counterpoise system. Mark pa1ssb heeft een 80 meter qro end fed gebouwd met een tegencappaciteit. 6m Omni Antenna. A simple transmitter, transmission line, and an “End-Fed” antenna WITHOUT a formal “Counterpoise” – We add a loss-less choke at the feedpoint, tune out it’s inductance with a capacitor, and see why common-mode current on the coax shield is the SAME as without the choke. 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. 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. 96% Nominal Velocity Factor. Neither configuration yielded a satisfactory match on 20m. 5' for 20m). high will yield good performance. 160 Meter Folded Counterpoise Inverted L Antenna - Duration: 18:21. No long counterpoise, radials or feedline required. 5MHz) therefore also resonant on second, third, and fourth harmonics, etc. counterpoise lengths for the U. That is the LNR end fed dipole which is for specific bands, ie. Figure 4-16. 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 more is possible 2 hours before sunset, 2 hours after sunrise. You can make it work on any band with the right length of antenna wire. BBC Radio 4, (longwaves) 1000kHz - 300m (=1MHz, medium waves) 10 MHz - 30m. An LED or other indicating. 5 Wave-Length wire on lowest band (130ft on 80m, 67ft on 40m) Fed from one end using a transformer in a box. This may be achieved by utilizing an extensive earth-net or counterpoise respectively in order to cover all short wave bands. Each counterpoise was "tuned" to length by adjusting for maximum current in the countepoise for that band. However, I'm experimenting with SDR quite a bit and would really like to bu. I've built a 2 meter ground plane antenna that works pretty well for RX and has a decent SWR on 2 meters with my Alinco. The coupler was tuned to resonance on the bench first using a resistive load. One other note. 150 the SWR was 3. I've just built an end-fed wire antenna and am using a 9:1 unun to feed it. radiator and the 13-ft. without radials and has a verry low swr combined with a low noise level. The magic is in the mathematical relationship between amateur bands. Nevertheless, I will also describe, how it is designed, if one decides to embark on building it for different bands. FULL HF Coverage, no tuner needed on most frequencies. It can be fed at the low impedance point at the centre as a half wave dipole or fed at the high impedance point at either end. New style resonant end fed antenna requires no counterpoise. ground-plane isn’t available. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. It shows the stainless steel bolt that acts as a probe for transferring RF energy into the liquid. I put up the 30 ft single wire end fed from a second story window and terminated it at about 7 feet. With the end-fed half wave version of the “Mini” and about 31′ of wire, we can get a 1. At first thought this would seem to be impossible yet many people have done it very successfully. Counterpoise is not required in this design. At zero counterpoise length, impedance is infinite and no current can flow, necessarily meaning that all working "end-feds" have a counterpoise of some sort, whether formally designed into the system or not. As others have stated, your coax is the other half of the antenna, and sometimes the 9:1 unun setup can be helped out with an extra counterpoise wire. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. php on line 117 Warning: fwrite() expects parameter 1 to be resource, boolean given in /iiphm/auxpih6wlic2wquj. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. A similar process was undertaken for the counterpoise. In 2000, Frank, DL7AQT, did lots of experiments with the Fuchs, and was happy to end up with a multiband. "EFHW" - the end-fed half wave antenna. What is claimed is: 1. Tuning end fed antennas Hi, I have been experimenting with end fed antennas, but for me they always need quite a high capacitor to tune them (150+pF) A friend of mine also is working with them, but he seems to need much lower capacitors (10-20pF) and uses beehive capacitors, he gave me one, but it has a too small capacitance for my antennas. This End-fed antenna has a rating of 2kw which is more than enough of a buffer for me. An end fed aluminium vertical antenna, capable of allowing the user to work 80m through 6m bands using an ATU, also not requiring any counterpoise & can be fed using coax cable. If the clamp is attached to a well earth object then a counterpoise may not be needed. To make the best use of an End-Fed antenna, it should be fed with a transformer. Recommended wire lengths and Installation Notes for Unun models 4932, 4935, 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. ***We make this same antenna design in many different lengths. I messed around with this quite a bit but I couldn't find a good length of antenna wire and feeder which made a significant improvement over the 'normal' sized version. HF End Fed Antenna 4 Bands 3-30 MHz Ham Radio No Tuner Needed. The following data are for the far field radiation patterns and 3D color views of an End Fed Half Wave Inverted-V antenna with the high point in the center at 40 feet and the ends about 10 feet over ground. In this configuration, the coax shield will act as your counterpoise. antenna, I hoisted the balanced line end to a height of ~20'. but not in a. The EFHW antenna is a popular choice among VK SOTA activators. com Here's a compact Top Band antenna system that actually plays with the big boys — no kidding! Let's begin at WØUCE's original 6 acre site in North Raleigh, North Carolina. One of the cautions you sometimes see in discussions of the end-fed antenna are "avoid multiples of a half wave. Counter to tuning a length of wire like you would with a dipole, with a random wire you don't. Depending on the length of the feedline, it may be either very low or very high. 8-30 is broadband and pretuned at the factory for an average SWR of 1. The physical length of any HF antenna is critical to achieving resonance and good performance on a particular band. 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. about 15-20 meter long if I use a 41 meter long antenna wire. As the feed point moves towards one end, the impedance gradually increases to 2kΩ or more. The SWR was adjusted using the tapping point on the coil near the feeder. It's a DIPOLE. To make the best use of an End-Fed antenna, it should be fed with a transformer. Yes, a giant yagi antenna on a tower would be ideal, but you said you wanted cheap. Using the technique of your choice, support the other end from a tree or other tall support. They rely on return ground currents and use the ground as part of the antenna system. Dropping the ability to tune in 160m seems an acceptable trade-off for the advantage of having a shorter multiband end-fed antenna with no counterpoise cables on the ground. At zero counterpoise length, impedance is infinite and no current can flow, necessarily meaning that all working "end-feds" have a counterpoise of some sort, whether formally designed into the system or not. I have suitable toroids for a transformer. to ensure great performance in a wide range of operating conditions. In designing a counterpoise for a medium-wave radio station, for example, radio-waves are a maximum of 566 metres (1,857 ft) long. Once again the antenna was shipped and received with in a few days. the coax as the return path for the minimal antenna currents. A 1/2-wave end-fed is also resonant and high-Z (radiation resistance, without any reactance). This may be achieved by utilizing an extensive earth-net or counterpoise respectively in order to cover all short wave bands. The raw End-Fed antenna will go through impedance swings as high as 5K Ohms, or more, at even. The UV resistant ABS plastic housing encloses an efficient matching network allowing the antenna to be fed with common 50 ohm coaxial cable on the SO-239 connection. Review (mpn: EF-53 for sale) EF-53 PRINCETON Meter Fed ANTENNAS Antenna Wire 80 6. I said it might, and that it might be worth trying as an experiment, on the bands where the antenna length is not resonant or close to resonance, that is, 12 and 17m. 47 free space wavelength) was determined by modeling the length required to obtain resonance (jX = 0) when the "counterpoise" was the same length. So when using an end fed make sure you have a good earth or fit a counterpoise. Your radio may be rated for 5 watts, but you'd be lucky to have a third of that power radiate from the antenna. How To Connect A Ferrite Antenna. No “ground” is available…so a high impedance antenna (a half wavelength wire fed at the end (half wave away from an open is an open)) is used to minimize the need for a ground reference or counterpoise. 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 ends of the wires feed through an antenna insulator appearing white in the photo above. I have changed the counterpoise wire from 1. After I had established my antennas for many of the HF bands; dipole for 80-40M and Hex beam for 20-10M, I turned my attention to 160 meters. The end fed offers many alternative options. Whether you're QRP backpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $49. Portable End-Fed 160-10 Meters Dipole Antenna George on 24th Feb 2020 This is the 4th or 5th product that I have purchased 4 or 5 items from ni4l. ; Easy Storage/transport. That's a lot of wire at, say, 3. Great, great choice of antenna. Counterpoise is not required in this design. The internal ATU on my Kenwood TS-590s tunes the W3EDP without problems from 80m right through to 10m once I connected a 20m counterpoise wire to the. The normal quarter wave ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding. I have inserted two additional links for coverage on 17m and 30m. length dependent. Portable or Stationary Multi-Band End Fed Half Wave Antenna This is a 200W version of popular EFHW-4010 End-Fed Half-Wave (EFHW*) antenna for 40/20/15/ and 10m bands. He used a T200-6 toroid (400 watts) with 35-36 turns coil. 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. As others have stated, your coax is the other half of the antenna, and sometimes the 9:1 unun setup can be helped out with an extra counterpoise wire. The cap is a 6 kV 101 pF. The end fed antenna system works well in horizontal, sloper, and vertical configurations. Ideal for camping, weekends away, holidays etc. 5' for 20m). The end fed long wire project. The formula for a half wave antenna, whether fed in the middle or at the end, is still the same. "Dublet" was the common name for this antenna when it was not a half. maybe better. Optional tuning stub ** Coax feeder. I have done several Field Strength Readings in the field and in a…. Chameleon Antenna is proudly manufacturing antennas that are 100% made in the USA. MFJ-1984HP come with 66 feet of wire and cover 40, 30, 20,15, and 10 meters. The length of the "antenna" is somewhat short for 80 meters, but performance on that band has been a big surprise. antenna wire is used for the most used operating band. and end fed antenna is a tough S. Later, shorter versions were found to work successfully, with a few concessions that we will discuss below. Tilted Folded Dipole Antenna 16 25. The ULTIMAX DXTREME end-fed antenna covering 1. This is showing the feed point SWR at 3200Ω. VHF/UHF/HF Basic HexTenna™ Vertical/Dipole. 03 'Length of coil SY L2=39. End-fed, half-wave antennas (EFHWs) are a half-wavelength long and are resonant. These antennas can be mounted horizontally, vertically or as a sloper. Note the lack of counterpoise of other ground connections. 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. No long counterpoise, radials or feedline required. Short waves 30 MHz - 10m short waves end 100 MHz - 3m. I understand the basic theory behind how the antenna works. Most END FED antennas on the market require a tuner, this one does not require one to operate. 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. However since the feedline is typically not 73 Ohms; specifically on the order of 300 to 600 Ohms, it will transform the feedpoint impedance to some other value. 5 metres to 6. The antenna. 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. The coax connector is at one end of the dipole, where it is most needed. This unit built fine and works when you understand it's limitations. The ATU can be used with end fed "aerials", including inverted L antennas. A 1/2-wave end-fed is also resonant and high-Z (radiation resistance, without any reactance). The sloper's feed point is anchored high above ground near the top of the tower on which sits a grounded HF yagi beam antenna. I have installed an inverted L, end fed antenna, with a single wire feed length of 31'-6" connected to an MFJ-941 Versa Tuner II. 5 meter long counterpoise. An end fed aluminium vertical antenna, capable of allowing the user to work 80m through 6m bands using an ATU, also not requiring any counterpoise & can be fed using coax cable. You can insert a 1:1 choke balun in the feedline to reduce the problem of RF in the shack but its placement will affect performance. By adding a 1/4-wave counterpoise, you, in effect, turn the antenna into an off-center-fed, vertically polarized 1/2-wave dipole.