Counterpoise Length For End Fed Antenna

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). If I can get away with end feed, and matching tuner, this is best. 5 metres long or 0. maybe better. A 1/4-wave end-fed is resonant and low-Z. Been thinking a lot lately about trying an end fed antenna. 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. 3:1 or better on all bands. - End-Fed antennas have wild impedance swings. The resistor should be the value that is appropriate. Web Site of PA3EKE Hy End Fed Antenna. A single non-resonant counterpoise with a length of 25 feet will provide satisfactory performance on all frequencies. The random wire with counterpoise (version 2) is a great option for backpacking/camping because it eliminates the need to bring a roll of coax but still gives good performance. The classic sloper antenna is a top-fed 1/4 wave vertical antenna sloping down and away from a tower. 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. 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. Volunteers of the Honolulu Emergency Amateur Radio Club (EARC) carefully assemble the 6-40 End Fed matchbox antennas for those who prefer not to build one. An HF antenna with a single wire feed (not coax fed). Because the electrical length is 33’, the radiator will b e a low impedance, or current fed antenna. 22 milli-metres. 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. Resources listed under Antennas for 80 meters band category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. Windom – Similar to the OCFD. 8 mm) of the end of that antenna is really the antenna, any length between the end that is bare (usually bright and shinney) is a coax line connecting the antenna to the receiver printed circuit board. A half-wave at the lowest band of interest will also work well on all harmonically-related bands which has become particularly attractive to those wanting a quick portable wire antenna. DERIVATIVES. Whether you're QRP backpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $49. A tuning circuit is coupled between the counterpoise conductor and a ground. End fed 5 band wire antenna for 80m, 40m, 20m,15m, 10m, short version with wire length 23m. 07mm stranded wire with an OD of 1mm. The antenna wire is 26 AWG copper clad steel wire with a great “silky” jacket. As for performance, 2m works better than any other HT antenna I’ve tried - not surprising considering it’s a full 1 ⁄ 4 wave in length. 0 'Height of ends above ground SY ApexHeight=4. 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. The key to these antennas is to have an elevated counterpoise. 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. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. Do You Need a Balun or Unun? I connect my 29-foot cheap HF antenna to a 9:1 unun to lower the impedance. Power: 100W SSB or 50W CW. 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. 5″ for 440) of stranded wire, crimped and soldered to a battery clip. Given this is MFJ, I expect there are compromises made to the transformer to get their product at the $17 price tag. There are a few easy to remember frequency to wavelength points: 200 kHz - 1500m. The antenna will be > >a. The ideal radiator length is one that avoid harmonic multiples (1/4 or 1/2) of the operating frequencies. ; Stainless Hardware, UV resistant materials throughout. I have an antenna relay on the mast which connects either the transmitters on the MN2000 tuner or the Icom on the AH4 tuner to the antenna. Recommended wire lengths and Installation Notes for Unun models 4932, 4935, 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. Click on Calculate and the optimum length for that combination will be displayed in feet, inches and fractions of inches, and in meters. FULL HF Coverage, no tuner needed on most frequencies. (For 20 meters) The length of 468/14. The end fed antenna system works well in horizontal, sloper, and vertical configurations. Fed via 9:1 Unun with second 9:1 Unun at far end feeding 50 ohm termination. 24 ft) is recommended. End Fed Half Wave (6. but not in a. End Fed Half Wave Antenna, 40/20/10 meters, QRP, 25W CW/SSB, 41 ft. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. without radials and has a verry low swr combined with a low noise level. This appears to give quarter wave antenna. Assuming the other wingnut is connected to ground, an extra length of wire as a counterpoise would probably help. ----- That is it! You are ready to start making contacts. While end loading is by far the most efficient of the three, rt is also the most demanding for good physical design. New style resonant end fed antenna requires no counterpoise. The end fed half wave. Using the technique of your choice, support the other end from a tree or other tall support. Ideal for camping, weekends away, holidays etc. An HF antenna with a single wire feed (not coax fed). It is only a quarter-wave on one band. While end loading is by far the most efficient of the three, rt is also the most demanding for good physical design. In the 80s, some Swiss OMs rediscovered the Fuchs Antenna Tuner, especially for portable use. Over lossy ground, especially when the antenna is low in height, feed resistance decreases even more. The counterpoise simply lays on the ground underneath the antenna and is also a random length. Although about 5S units down from my 20-40-80 fan dipole center up at 30′, with one pre-amp on the end-fed 5-6 feet up matched the fan dipole. I am not a mathematician that calculate ohms, coils etc. One such antenna is the W3EDP end fed. Hi, For sale here is our End Fed Half Wave (EFHW) antenna for 10m-80m. [citation needed] To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. kubark42 op 9 mei 2013 om 02:00 schreef: Too bad it won't work at those frequencies. The black dots represent exact harmonics of the 3. Add three more 20 ft counterpoise for a total of 4. The simulations were performed for ideal (lossless) antenna elements with a diameter of 1. 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. 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. but not in a. Manufacturer do not provided a ground/earth plane for the antenna, only a tuned radial, or counterpoise as it is called some times. If using coax in this manner, does the coax need. The Zeppelin Antenna. If we don't isolate the ground path in this small non-resonant radial system, as much as 5 dB loss can occur. The W3EDP end fed wire antenna lends itself readily to QRP and portable operation. The overall length, deployed, is 52″, and can be disassembled to it’s longest piece being only 6. This is showing the feed point SWR at 3200Ω. My antenna is NOT an end fed Dipole. End-fed wires resonate on their 1/2-wave fundamental frequency plus all odd and even harmonics above. 0:1, depending upon the frequency used and surrounding objects, ground conditions, etc. Here is a side view of the equiptment. 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. If you don't specifically provide one then the coax shield will act as the counterpoise. The graph below (fig. Great job, look forward working summit to summit, end fed to end fed. Web Site of PA3EKE Hy End Fed Antenna. Most END FED antennas on the market require a tuner, this one does not require one to operate. This antenna is grounded thus giving les static noise to your receiver. [citation needed] To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. This calculator is designed to give the vertical length (height) of a quarter wave ground plane antenna, and the length of each of the four radials (often called radiators) for the frequency chosen. The normal quarter wave ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding. and end fed antenna is a tough S. It's a DIPOLE. Great job, look forward working summit to summit, end fed to end fed. Rma required to return an item. In the 80s, some Swiss OMs rediscovered the Fuchs Antenna Tuner, especially for portable use. I made a new Link Multiband EFHW for 15/20/40 2 weeks ago. I chose the EARC end fed 6-40. The counterpoise simply lays on the ground underneath the antenna and is also a random length. [citation needed] To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. Some of the articles I found say that for a 1/2 wavelength end-fed I need a "small to no counterpoise" (with a lambda*0. 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. This antenna works on 80 - 40 - 20 -15 and 10m. Small enough to fit in your glove box or your bug-out bag. This problem usually is worse with a End-Fed antenna that the manufacturer told you doesn't need a counterpoise. 600Ω Open Wire Ladder Line Doublet. SWR will vary based on topography, proximity of nearby structures, configuration of the antenna wire and choice of ground or counterpoise. Fed at 34% from the end, it uses a single feed wire and can be resonant on more than one band. 05 lambda counterpoise to work correctly. The antenna will be > >a. The resulting antenna has the same strength as a one piece structure. 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. For the 80m-band accordingly at Lambda 1/4 a wire length of 20,8m (68. The compromise found by G5RV is only one of many. 07mm stranded wire with an OD of 1mm. Base End-Fed antenna for 20m, 10 meter in length. Length of counterpoise should be approx. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. Attic antennas •Many types of antenna can be mounted in the attic IF you don't have Radiant Barrier (Tech Shield). I'm quite impressed with it so far. End-fed, half-wave antennas (EFHWs) are a half-wavelength long and are resonant. 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. 5m) end-fed is insulated for safety. An LED or other indicating. QRP Multi-band HF EFHW antenna for SOTA Post updated 29 September 2017. The key to end fed antenna success is the matching network interface between the long wire antenna and the coax feed line and feed line choke at the transceiver. Next, create the counterpoise. For instance, the ½-λ end-fed whip can be hoisted into a tree or suction-cup mounted to a window and fed with small coax from the HT. Shorter length counterpoise wires can be used of operation is confined to 40m or higher. a ground plane. 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. I have one question, build an antenna for cb 27Mhz vertical dipole. 5″ for 220 and 6. (I think Eric recommended somewhere around 28’ depending on the band coverage). The key is the wire can only be one of a few lengths if you want it to work on just about all the high-frequency (HF) amateur radio bands here in the USA and the rest of. 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. For instance, the ½-λ end-fed whip can be hoisted into a tree or suction-cup mounted to a window and fed with small coax from the HT. Established in 2008, Chameleon Antenna has been a great source of enjoyment for amateur radio operators. A radial/counterpoise field is not necessary with this EFHW wire antenna. The feed line enters at the left end and the first few inches of the half-wave radiating element can be seen at the right. If you droop each end down by 5 metres then you'll be able to fit it into a 20 metre span. The end fed antenna has a 9:1 unun which tames the impedance. There has been much written here about counterpoise ground installation, but after reading many post, reference books, etc. End Fed Wire Antenna. A 160-meter system might require 16 feet of counterpoise height, and that will directly subtract from effective radiator height. 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 Horizontal Wires (EFHW) cover multiple bands with-out. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. The normal quarter wave ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding. I decided to bring an end fed antenna to the party. 1: The end-fed antenna, the simplest of all multi-band antennas Fig 15. End fed 5 band wire antenna for 80m, 40m, 20m,15m, 10m, short version with wire length 23m. The measurements below are for building a simple Dipole Antenna. Directivity with the Counterpoise An additional benefit of using wire counterpoise with a rubber duck, ¼-λ whip, or ½-λ end-fed whip is that the resulting antenna can be made. Questions: 1. Because the electrical length is 33’, the radiator will b e a low impedance, or current fed antenna. As in any vertical type antenna, a ground radial system or counterpoise is essential for maximum results. Portable operation could not be easier. Then riveted. This is what I use with I go portable camping. It is at this BASE that the Ground Rod is installed. Your complaints of RF in the shack are to be expected and tough to kill unless the system is set up properly. 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. I understand the fact that these types of antennas need a good ground/counterpoise network etc,and have RFI isues etc, which I fully understand. 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. 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 random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feedline, and all the rest that goes. This is the impedance matching transmission line portion of the 2nd APRS antenna built and used for SABLE-1 & SABLE-2. Questions;. As per my knowledge any base fed antenna without a counterpoise is in reality only half an antenna. MFJ-1982HP EndFed 1/2 Wave 800W 80M-10M Wire Antenna 132 feet. The yagi plays the role of a ground plane, while the tower plays the double role of reflector and grounding "rod". Power: 100W SSB or 50W CW. A counterpoise is simply a length of wire laid on the ground and connected to the earth connection on the Paraset. (Counterpoise) In the case of the End Fed antenna, you can simply make an extra connection and connect it to the coaxial cable shield. Fine Tuning the End Fed Antenna. Recall that an ideal quarter wave monopole over an infinite conducting surface has a radiation resistance of around 37 Ohms (1/2 of a free space half wave dipole). g - An antenna, rated for 50 ohms impedance with 18 feet of coax, over a counterpoise that forces the antenna to become a radiator that is now presenting 120 ohms of impedance. The larger the wire, the wider the bandwidth. 5′ long counterpoise. 5 meter long counterpoise. The end-fed feature adds convenience, and makes it very portable. To work well, however, the ground side of the antenna tuner needs to be connected to a network of radial wires, or a counterpoise. It is a resonant Half wave low on 80m (3. Simply type --- end fed antenna ---- into the search box and it will take you to all of our "QSO-KING" models. The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. End fed 5 band wire antenna for 80m, 40m, 20m,15m, 10m, short version with wire length 23m. Make one of these antennas for your emergency "go-kit. RE: Random wire antenna: counterpoise length? - zs6bzm - 10-06-2016 Hi Jim, If you get a 9 to 1 unbalance to unbalance Balun with 16. 8m) of 100ft (30. A single non-resonant counterpoise with a length of 25 feet will provide satisfactory performance on all frequencies. 32, “An Unorthodox Antenna”) is an 84′ long end fed and a 17′ long counterpoise (6. Ok friends, need some help understanding. The AP-10B utilizes a counterpoise to make the antenna function properly. The compromise found by G5RV is only one of many. This is a good example of an End Fed Half-Wave antenna that radiates almost as well as the reference dipole and seems to do so without regard to adding an appreciable counterpoise system. Last up was the 20m antenna. If it is shorted at the far end, the impedance is high at the near end. A termination resistor at the far end absorbs reflected wave along the antenna Counterpoise wire running under Vee connects the ground posts at each end. Short video on a simple multiband HF antenna (w/tuner) you can put on the air with a few mulitpurpose items in less time than it takes to watch this video. 3:1 with a counterpoise of 15. 2MHz, ground mounted) SWR – Actual bandwidth on the 50Ω side of the coupler will be much narrower, due to the tuned circuit we are using. The primary side (50 Ohm) should have an inductive reactance of at least 4 times the input impedance for a broadband transformer. Note that any of these lengths are going to be long on 6 meters. Most of the material I have read on the net about this type of antenna says the coax is used as the counterpoise but none discuss the coax length. For better effciency with the counterpoise, you can build or buy (the MFJ Artificial Ground) a counterpoise tuner. A single non-resonant counterpoise with a length of 25 feet will provide satisfactory performance on all frequencies. CM End fed multi-band using a single coil to adjust resonance CM CE SY L1=2. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. There are a few easy to remember frequency to wavelength points: 200 kHz - 1500m. You can't get much cheaper than that. Assuming the other wingnut is connected to ground, an extra length of wire as a counterpoise would probably help. You can make it work on any band with the right length of antenna wire. The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feedline, and all the rest that goes. Steve Ellington 19,049 views. I have NO rf in the shack. A definite must have accessory for radio amateurs using random length or inverted L antennas. 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. As a result, if the ground sucks, the antenna will also. Counterpoise is not required in this design. Most of the material I have read on the net about this type of antenna says the coax is used as the counterpoise but none discuss the coax length. Here are some photos of one of my 9:1 baluns. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6. 40-10 Meter Coverage, no tuner needed on most frequencies. The key to end fed antenna success is the matching network interface between the long wire antenna and the coax feed line and feed line choke at the transceiver. No counterpoise needed but grounding is recommended on permanent installations. I have done several Field Strength Readings in the field and in a…. On higher floors you'll need a counterpoise. If we don't isolate the ground path in this small non-resonant radial system, as much as 5 dB loss can occur. 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. End-fed wires resonate on their 1/2-wave fundamental frequency plus all odd and even harmonics above. If it is shorted at the far end, the impedance is high at the near end. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. If you don't specifically provide one then the coax shield will act as the counterpoise. But it is a problematic dipole:. 24 ft) is recommended. A multi-band end fed wire antenna presents a potential problem in that a ¼ wave length antenna cut for say the 80 metre band will present a feed impedance of about 70 ohms however when the same antenna is used on the 40 metre band the feed point impendence will be several thousand ohms and therefore difficult to achieve a match even with a. 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. 05 of a wavelength on 40m. 05 lambda counterpoise to work correctly. Also another unusual coincidence is that the length of my counter poise wire that I made a year ago, also happens to be close to the length of the NA-771 antenna (counterpoise is 16. (I think Eric recommended somewhere around 28’ depending on the band coverage). In this configuration, the coax shield will act as your counterpoise. Displacement is the term used for the distance between the counterpoise (which is the antenna system's lowest element) and the ground. Any other 50 ohm fed resonant or broadband antenna Efficiency and stable tuning of the end fed antennas is greatly improved by use of a counterpoise wire (or ideally several) and these were available in both portable and fixed site versions. It consists of an 85ft wire fed against a 17ft counterpoise (attached to the earth point on the ATU). SWR will vary based on topography, proximity of nearby structures, configuration of the antenna wire and choice of ground or counterpoise. 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. It is a resonant Half wave low on 80m (3. Rma required to return an item. Base End-Fed antenna for 20m, 10 meter in length. The finished End Fed Half Wave antenna coupler. It's a decent match on everything from 40m to 10m, but i was wondering about the effect of the length if the counterpoise. Delta Fed Dipole Antenna 13 18. To capture the 80m‐Band the counterpoise cable length has to be at least 80m x 0. counterpoises is better. Call us at from central time m f or use messaging sales for us customers only8 Kansas residents pay sales tax. A dipole can be fed anywhere along its length. Assuming the other wingnut is connected to ground, an extra length of wire as a counterpoise would probably help. While end loading is by far the most efficient of the three, rt is also the most demanding for good physical design. In my case for me to work 40/80 meters I had to increase length to around 67' otherwise this antennas was numb to the lower 2 bans. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6. Is there any particular gain advantage?. The ideal radiator length is one that avoid harmonic multiples (1/4 or 1/2) of the operating frequencies. MFJ-1984HP come with 66 feet of wire and cover 40, 30, 20,15, and 10 meters. Length: 73’ + 25″ Copper Clad KEVLAR PTFE (Teflon) (-70°C to 150°C) wire. End Fed Half Wave Antenna Coupler Schematic – 7-30MHz For calculating the length of a half wave in metres, I use 141÷ƒ(MHz) for wire elements. The feed through insulators allow the antenna and counterpoise wires to exit the house. That's a lot of wire at, say, 3. The end fed 1/2 wave antenna, much like the 43 foot vertical, has become a cult phenomena. Attach one end of your antenna wire to one of the binding posts, either directly or using a jumper wire. If using coax in this manner, does the coax need. 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. •Requires a 0. 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. This is purely unintentional as I had made that wire at least a month or two before I ever knew about the aftermarket antennas. 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,. I have the current Rybakov antenna setup as a baseline. This helped only a bit. Remember that the antenna tuner wants to match the antenna and transfer as much RF energy to it as possible. 8m) of 100ft (30. The FCP: A 160 Meter Counterpoise for a Postage-Stamp Lot Guy Olinger, K2AV / [email protected] The antenna was deigned for the ham radio bands of the day: 160, 80, 40, 20 and 10 metres. I understand the fact that these types of antennas need a good ground/counterpoise network etc,and have RFI isues etc, which I fully understand. [citation needed] To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. 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. Reference site: Steve Yates AA5TB The End Fed Half Wave Antenna. The counterpoise is the mirror image of the electrical side of your antenna. However, when using it with an End-Fed antenna it is wired as a (so-called) "unun" transformer (unbalanced to unbalanced). SOTAbeams Half-Wave End-Fed Portable Antennas are half-wave end-fed antennas for hams on the move. What I do is fiddle with the analyzer and antenna tuner to get 1. Depending upon the performance of your antenna tuner, most operators can expect to easily tune 40 meters through 6 meters when using a 16 to 33 foot coax and a 33 to 66 foot. Counter to tuning a length of wire like you would with a dipole, with a random wire you don’t. Higher almost always. Your radio may be rated for 5 watts, but you’d be lucky to have a third of that power radiate from the antenna. I also chose to use a counterpoise of 16 feet of Wireman 532. The antenna may work best with the counterpoise not connected to the ground side of the balancing network. Recall that an ideal quarter wave monopole over an infinite conducting surface has a radiation resistance of around 37 Ohms (1/2 of a free space half wave dipole). End Fed Half Wave Antenna Coupler Schematic – 7-30MHz For calculating the length of a half wave in metres, I use 141÷ƒ(MHz) for wire elements. 5 metres long or 0. As in any vertical type antenna, a ground radial system or counterpoise is essential for maximum results. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. It is essentially a vertical dipole, in which one side of the dipole is the RF image of the antenna in the ground. The Wire Size can range from 16 AWG to 12 AWG. 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. All on one end fed wire. Be careful of power lines and other hazards! 8. The resistor should be the value that is appropriate. Other designs, such as the popular commercial EFHW-8010, connect it to s separate screw/output so that you can either connect a short counterpoise or connect it to a ground rod. A tuner placed at the transmitter, fools a transmitter into working correctly. " A properly designed random length wire antenna can be used for portable or home operations. ground-plane isn’t available. The SE-360 is an end fed vertical fibreglass antenna capable of allowing the user to work 80 meters through 10 meters using an ATU, also not requiring any counterpoise. Note that any of these lengths are going to be long on 6 meters. To make the best use of an End-Fed antenna, it should be fed with a transformer. Some words of caution are in order, however, if you plan to use your rainspout as an antenna:. It uses The counterpoise should be 3 to 4 inches above ground. Once again the antenna was shipped and received with in a few days. The number of variations are endless. Above is a close up view of the current amplitude and phase distribution at the left hand side of the antenna system. 6 m with a 5. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. 2 enD-FeD AntennAS Another common antenna system for multiband opera-tion is the end-fed Zepp antenna shown in Figure 10. Bow-Tie Dipole Antenna 14 20. The antenna is sported by a 22ft (6. The first thing I did was buy some 24 guage black wire, specifically this 100 foot spool. This antenna has been made popular by the Emergency Amateur Radio Club of Hawaii (EARCHI). This antenna never could resonate on 30meters with builtin antenna tuners. So if I use a 21 meter long wire, I take a 10. It's a decent match on everything from 40m to 10m, but i was wondering about the effect of the length if the counterpoise. Established in 2008, Chameleon Antenna has been a great source of enjoyment for amateur radio operators. dipole on a vehicle. 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. I decided to start with a short 40/20/(15?)/10 meters version without any loading coils. Not bad for a relatively small antenna. This antenna build was strongly inspired by the well known PAR end fed antenna. Keep in mind. I've just built an end-fed wire antenna and am using a 9:1 unun to feed it. What else can I say? The total length of the MV-5+3 antenna is approximately 3,2 meter. However, I'm experimenting with SDR quite a bit and would really like to bu. Above applies when in free space. 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. Mark pa1ssb heeft een 80 meter qro end fed gebouwd met een tegencappaciteit. 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. The graph below (fig. Antenna projects for 80 meters band category is a curation of 169 web resources on , The CN2WW 80m wire-beam, Vertical antenna for 40 and 80m, Phased Delta Loops. The Zeppelin Antenna. However, I'm experimenting with SDR quite a bit and would really like to bu. 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 have an antenna relay on the mast which connects either the transmitters on the MN2000 tuner or the Icom on the AH4 tuner to the antenna. Here's a great end-fed long wire 80 - 10 Meter multi-band antenna. But you will introduce another potential source of. PVC is a soft material so it is not unusual for the rivets to want to pull through. Small enough to fit in your glove box or your bug-out bag. I have one question, build an antenna for cb 27Mhz vertical dipole. 5MHz) therefore also resonant on second, third and fourth harmonics etc. 8 metres long. Certainly, this antenna (even though it's called a "dipole") does not perform as well as a center-fed dipole in the same configuration, nor as well as an end-fed half-wave. Theoretically the capacitance to ground of the upper and lower arms of the dipole. 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). I don't have a counterpoise but rather use a ground connection from the 9:1 unun to the mast which is grounded well. My take on a QRP HF EFHW inverted V antenna designed for use on five amateur radio bands…. 950MHz with an SWR of 1. 2/ I also want to make a multi band portable aerial for HF, as portable as possible. Great, great choice of antenna. 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. 0 'Length from start to coil SY Lcoil=0. There is also included a 20m rope for installation. The coupler was tuned to resonance on the bench first using a resistive load. Length of antenna wire is 19. This is an End Fed Long Wire wire antenna that will cover all bands from 160 to 6 meters, including the WARC bands, as well as 60 meters and MARS frequencies. 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. 80-10 Meters. One such antenna is the W3EDP end fed. A definite must have accessory for radio amateurs using random length or inverted L antennas. (End-fed 1/2 wave feed impedance decreases, while center fed half-wave antenna impedance increases with added loss!) With a small counterpoise and end-feed we need to: keep the antenna clear of lossy media including the earth. ; Stainless Hardware, UV resistant materials throughout. 商品名 HFedz 160m/80m/40m End Fed Half Wave (49:1 EFHW) HF HAM Radio Antenna(HFedz 160m/80m/40m End Fed Half Wave (49:1 EFHW) HF HAM Radio Antenna) 商品画像一覧 商品説明 ※アメリカの現地出品者により作成されたため、英語のまま掲載いたしております。. 0:1, depending upon the frequency used and surrounding objects, ground conditions, etc. I understand the basic theory behind how the antenna works. The Hertz antenna is an antenna with an electrical length of a half wavelength at its resonant frequency. Taking this to the extreme is to feed the half wavelength antenna at its end. When buried in the ground, its effective length changes a lot. I know that i have to use a counterpoise for my setup, but i am unsure if my location for it (the lime green line) is acceptable with the placement of my antenna wire. The End-fed Half-wave (EFHW) EFHW antenna without a counterpoise may well give rise to problems of various sorts; it's parallel tuned, and the antenna length is selected to give good performance on the traditional ham bands, although mine works well on the WARC bands, too. A ¼ wavelength of transmission line is use to transform the Hi Z of the antenna to Lo Z for the transmitter. 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 wire was either thrown up in a tree or attached to my 20 ft. 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. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. 950MHz with an SWR of 1. The black dots represent exact harmonics of the 3. As in any vertical type antenna, a ground radial system or counterpoise is essential for maximum results. What I do is fiddle with the analyzer and antenna tuner to get 1. This calculator is designed to give the vertical length (height) of a quarter wave ground plane antenna, and the length of each of the four radials (often called radiators) for the frequency chosen. The length of the counterpoise depends on the antenna wire or. It consists of an 85ft wire fed against a 17ft counterpoise (attached to the earth point on the ATU). The End-fed antenna with a 1:64 Matching Auto Transformer is well worth building. •Need lots of room, keep. "Dublet" was the common name for this antenna when it was not a half. Also another unusual coincidence is that the length of my counter poise wire that I made a year ago, also happens to be close to the length of the NA-771 antenna (counterpoise is 16. This is an End-Fed Half-Wave (EFHW*) antenna for 40/20/15 and 10m bands. long (or multiple) and fed with a 1/4 WL (or multiple) open wire feed line which uses only one of the wires. It is a resonant Half wave on 80m (3. Call us at from central time m f or use messaging sales for us customers only8 Kansas residents pay sales tax. According to some sources (ref. Wire type: Copper stranded Color: Grey or Black depending in stock. The key is the wire can only be one of a few lengths if you want it to work on just about all the high-frequency (HF) amateur radio bands here in the USA and the rest of. Evolving from a simple end-fed Marconi for 80m, the idea was to use the opposing. My antenna is NOT an end fed Dipole. 66) end support. The antenna. Coax feed line between the impedance matching unit and the radio is a 2 metre length of RG58AU. 2 m radial, giving a vertical cut at l/2. 96% Nominal Velocity Factor. Questions: 1. This antenna build was strongly inspired by the well known PAR end fed antenna. When I was KL7FRY in 1966-67, my antenna was a 2000' end-fed long wire. That would make your end-fed antenna 150 feet long which is not a problem in itself. Tune for minimum. I've brought this up enough times already; let's de-mystify this beast. 66' Length. 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. As per my knowledge any base fed antenna without a counterpoise is in reality only half an antenna. Counterpoise can be in the same plane as the antenna (i. Jack greatly enjoyed big 160 meter transmit and. 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. Therefore, the counterpoise should extend 282 metres (925 ft) from the. Minimal counterpoise/radial requirements make for a convenient antenna for portable use, and I operate portably about 99%. 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. - a resonating 40m long end fed wire - a Zeppelin antenna (40m end fed wire with a 1/4 wave "chicken ladder feeder") - extra 1/4 wave radials on the roof - a metal rain gutter as extra "counterpoise". This antenna is depicted in Figure 2 24 Figure 2 24 End fed half wave antenna d from CCE Java at Lebanese International University. Ideal for any kind of outdoor activity like SOTA, hiking, holidays, camping etc. 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). A termination resistor at the far end absorbs reflected wave along the antenna Counterpoise wire running under Vee connects the ground posts at each end. (6) Enjoy your new antenna. Tuner & counterpoise efficiency tests using an RF Current sensor The objective of these tests was to try to determine: 1) The most efficient combination of tuner and counterpoise that will produce greatest RF current in a half wave, end-fed, field deployed, 40m, antenna. Since the band in question is 80 metres the counterpoise will be shorter than the resonant length for this band as it is laying on the ground and so. The UNUN transformer and connecting. Your radio may be rated for 5 watts, but you’d be lucky to have a third of that power radiate from the antenna. Now on to testing the both end fed antennas. Throw out the coax length, and use an abritrary length - say 14 feet. Posts: 58 The W3EDP antenna (pic attached) seems a popular length of end-fed antenna, being 25. Rugged weather-resistant 50-Ohm matching network. By adding a 1/4-wave counterpoise, you, in effect, turn the antenna into an off-center-fed, vertically polarized 1/2-wave dipole. Short waves 30 MHz - 10m short waves end 100 MHz - 3m. MFJ-1982HP EndFed 1/2 Wave 800W 80M-10M Wire Antenna 132 feet. Mark pa1ssb made a qro 80 meter end fed antenna with a counterpoise. It utilizes a 9:1 UNUN transformer in order to bring the impedance of the antenna to more manageable values for your antenna tuner. This configuration is terribly inefficient because the antenna is a fraction of a wavelength it should be. 150 the SWR was 3. I'm quite impressed with it so far. Please see our other "QSO-KING" antennas on E-Bay to find the perfect length for you. Great job, look forward working summit to summit, end fed to end fed. Of course that’s the same potential of the rig via the coax braide. Others say that you can use a 6. But you will introduce another potential source of. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. You would eliminate a source of unwanted interference: the "floating coax shield". Mark pa1ssb heeft een 80 meter qro end fed gebouwd met een tegencappaciteit. End Fed Halfwave. Andrew VK1AD / 08/08/2014. Ideal for camping, weekends away, holidays etc. This unit built fine and works when you understand it's limitations. 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. Shorter length counterpoise wires can be used of operation is confined to 40m or higher. (For 20 meters) The length of 468/14. length wire antenna, collapsible whip, universal mount, and counterpoise wire. The EFHW is an ideal antenna for SOTA, it’s easy to deploy and can be fed with a sort length of coax. Based on my experiments, if an end-fed antenna is called for, a random length of wire and a counterpoise (along with a suitable antenna tuner) will probably serve you better. If it isn't end-fed, then it's usually near-center fed and becomes a dipole antenna instead. This article will describe a 40/30/20m band end-fed half wave antenna, focusing on its matching unit. Most of the material I have read on the net about this type of antenna says the coax is used as the counterpoise but none discuss the coax length. ; End-Fed Horizontal Wires (EFHW) cover multiple bands with-out. The antenna current at midpoint was 210 ma. When I tune on 20m and 17m, the rig's SWR display indicates the SWR nudging 2:1. The finished End Fed Half Wave antenna coupler. A radial/counterpoise field is not necessary with this EFHW wire antenna. A counterpoise is simply a length of wire laid on the ground and connected to the earth connection on the Paraset. As with most End-fed antennas an antenna tuner in needed and I have my new LDG AT200proII. 950MHz with an SWR of 1. 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 counterpoise simply lays on the ground underneath the antenna and is also a random length. •Need lots of room, keep. Similar in construction to the X200A dualband, the V2000A has an additional counterpoise radial – adjustable for 6m (52-54 MHz only). If you are in a hurry you can throw it over a small tree. The length of counterpoise should be a minimum of 30 to 40 feet but not the same length as the antenna wire. 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. When I tune on 20m and 17m, the rig's SWR display indicates the SWR nudging 2:1. To operate on any HF band you need a wide range tuner like the internal. This method is often called the END-FEED or VOLTAGE-FEED method. The AP-10B utilizes a counterpoise to make the antenna function properly. 7m) central support and a 12ft (3. Step#4 --- Attach the end of the antenna wire with the insulator to a high support. length of coaxial cable to distance the antenna wire from the operating position. Don't forget to connect your antenna system to a good radial or counterpoise system. Thanks for the great article, though. > > > >Thus a monopole. Their antenna designs have inspired other companies to also rethink their own antenna systems. 5 MHz, but you can loop the wire around the room and hide it from view. Be careful of power lines and other hazards! 8. The formula for a half wave antenna, whether fed in the middle or at the end, is still the same. A dipole is impossible with > >our planned deployment design due to risk of entanglement. 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. Here is a side view of the equiptment. 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 random wire with counterpoise (version 2) is a great option for backpacking/camping because it eliminates the need to bring a roll of coax but still gives good performance. A 1/2-wave end-fed is also resonant and high-Z (radiation resistance, without any reactance). 22 milli-metres. End Fed Half Wave Antenna Coupler Schematic - 7‐30MHz Minimum counterpoise: Metres End Fed Half Wave (6. counterpoises is better. 03 MHz fixed, with the least components. Keep in mind. 5′ piece of wire. A spade connector is provided for the counterpoise, but the user supplies the 16. Here is a closeup of the end cap. Stainless Hardware, UV resistant materials throughout. Usually it is a simply a Dipole, fed in the middle with openwire feedline. So, with just a short 3 foot counterpoise this antenna should be as efficient as a half wave. I have a length of 14 gauge wire that has ring connector on one end and a female spade connector on the other. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. 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). OK, call me an antenna snob, but in my opinion the End Fed Half Wave antenna is about as good as it gets for an easy to put up, great performing antenna. G5RV Antenna 15 22. " A properly designed random length wire antenna can be used for portable or home operations. Specially made for the portable user comes complete fixed with winder to unun to store away with ease while on the move. The coax connector is at one end of the dipole, where it is most needed. 5K End Fed Long Wire Antenna / 160-6m / 1500W-max. End fed 7 band wire antenna for 80m, 40, (20m, 17m) 15m, 12m, 10m. Initially these antennas were one half wavelength long on the lowest operating frequency. 21 'Length of whole antenna SY L=4. Because the electrical length is 33’, the radiator will b e a low impedance, or current fed antenna. Someday, when I get around to setting up an antenna at home, an end-fed antenna is probably what I’ll use because my lot makes radials a challenge. 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. Fine Tuning the End Fed Antenna. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. The transformer is designed with a medium power single core 4:1 voltage Unun. I'm quite impressed with it so far. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6. End Fed Half Wave Antennas VS Random Length End Fed Antennas - Duration: 18:04. Due High Impedance feed point, the antenna is less. The antenna current at midpoint was 210 ma. One such antenna is the W3EDP end fed. With my 80m EFHW wire cut for lowest SWR when plugged into the 1:64 jack I get a perfect match on 40m (end fed full wave in this case) when plugging it in for a 1:25 transformation – however the antenna is wildly zig-zagging in close proximity to the building, part of it is even in the attic, so other setups may return different results. SWR will vary based on topography, proximity of nearby structures, configuration of the antenna wire and choice of ground or counterpoise. (Haven’t tried it. Simply hang the far end from. 18m counterpoise. 66' Length. A BALUN is needed to isolate the antenna common mode current from the station. The problem with an end fed half wave antenna is that the antenna presents a high impedance, creating a significant miss match with the usual transceiver. MFJ-1984HP END FED, 1/2 WAVE, 40-10M, 800W, WIRE ANTENNA End-Fed Horizontal Wire antennas (or EFHWs) cover multiple bands without traps, stubs, or resonators. I was searching for DIY end-fed antenna. Recall that an ideal quarter wave monopole over an infinite conducting surface has a radiation resistance of around 37 Ohms (1/2 of a free space half wave dipole). These antennas can be mounted horizontally, vertically or as a sloper. that I have yet to find another experimental indoor antenna that can beat it, including magnetic loops, crossed field loops and EH antennas. End fed 7 band wire antenna for 80m, 40, (20m, 17m) 15m, 12m, 10m. The number of variations are endless. Hi, I am interested in end fed aerials. NO counterpoise needed! Frequency coverage: 7-30MHz Resonant on 40/20/15/10m Wire length ~63 feet Power Handling: 200W I. This is showing the feed point SWR at 3200Ω. This End-fed antenna has a rating of 2kw which is more than enough of a buffer for me. Length: 60' Weight: 1. However, I'm experimenting with SDR quite a bit and would really like to bu. End Fed Halfwave. 30 Watts PEP. 5 MHz, but you can loop the wire around the room and hide it from view. - Radials are not a counterpoise - they are a capacitive coupling between the antenna and the Earth. As for performance, 2m works better than any other HT antenna I’ve tried - not surprising considering it’s a full 1 ⁄ 4 wave in length. If you are only interested in operating 40 through 10 meters, you can try 36, 44, or 49 feet. Questions: 1. End Fed Half Wave Antennas VS Random Length End Fed Antennas - Duration: 18:04. Antenna winder: TET-Emtron (Perth), Squid Pole: Harverford (Sydney). To use it on 30, 12 and 24 meters does require a tuner. I came across EFHW antennas a while back when I was just starting to figure out antennas. connected to the ground lug on the network of the antenna and you're ready to go. Thanks for the great article, though. However, when using it with an End-Fed antenna it is wired as a (so-called) "unun" transformer (unbalanced to unbalanced). A spade connector is provided for the counterpoise, but the user supplies the 16. The Hertz antenna is an antenna with an electrical length of a half wavelength at its resonant frequency. For the past couple of weeks, I've been playing with end-fed wire antennas. Fast Setup and takedown. 05λcounterpoise •Transformer is a toroid with N:1 turns between primary and secondary •Capacitor should be in range to resonate at the operating frequency with the. 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. and end fed antenna is a tough S. This is what I use with I go portable camping. But it is a problematic dipole:. The overall length, deployed, is 52″, and can be disassembled to it’s longest piece being only 6. I have NO rf in the shack. Would this setup be effective for the 15 meter band without the use of antenna tuner (since the 15 meter. Wanted to get some thoughts from folks about pros and cons of an end fed half wave for portable/SOTA use, as opposed to just using a random length wire with a counterpoise connected directly to either the KX2 or 3. Steve Galchutt, WG0AT, uses a 58-foot wire length with a 25-foot counterpoise. An adaptive antenna system having a counterpoise conductor contained within a housing of a communication device and located distally from such surfaces of the housing that can be held by or placed in proximity to a user or external objects which detune the counterpoise. We've been in the radio business for over 15 years and sold hundreds of these antennas to satisfied hams. Been thinking a lot lately about trying an end fed antenna. The length of the "antenna" is somewhat short for 80 meters, but performance on that band has been a big surprise. 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. Under the black line is the End Fed Wire, above the black line the MV-5+3 antenna. S Stainless Steel hardware Stealth Marine #18 AWG. When I tune on 20m and 17m, the rig's SWR display indicates the SWR nudging 2:1. 6 m with a 5. If I can get away with end feed, and matching tuner, this is best. There's many info in the internet, Google is your friend HI. Call us at from central time m f or use messaging sales for us customers only8 Kansas residents pay sales tax. 75', 3/16" 100% Dacron Polyester Rope. 7m) central support and a 12ft (3. Placing radials in soil DEGRADEs effectiveness compared to elevated radials but in ground is more practical. 2 MHz the antenna wire is 32. It is fed by an trivially small transmitter at the base of the vertical section using an ideal current balun. Not bad for a relatively small antenna. Attach one end of your antenna wire to one of the binding posts, either directly or using a jumper wire.