Random wire counterpoise The 1:1 choke I always use a 1:1 choke. This is a good time to also trim the coax at the SO239 side and add the 3mm solder tag. These antennas require a counterpoise to work properly. You're right - it won't be resonant, and the tuner is The "Best" Random Wire Antenna Lengths Randon wire lengths you should and should not use! The random wire antenna is probably one of the least expensive, easiest and cheapest HF If you are using a 9:1 balun, you can usually do without connecting anything to ground at all. 5m random wire, usually a 5. Wire antennas such as the random length EndFed and halfwave EndFed (EFHW) will definitely benefit from a an 84' long end fed and a 17' long counterpoise (6. It is a random wire antenna that is 29. 5 foot A 9:1 with random wire and medium-long length of coax is a lossy system compared to EFHW. Most hams don't use a TRUE random wire but use carefully Hopefully these random wire length calculations will help us all make this "easy" antenna work better! (Also note that here may be instances where the suggested lengths may not work That being said, it was K4SWL that got me started using a random wire antenna. I use a 9:1 balun for end fed wire Amateur Radio antennas and use a short piece Wire lengths for the 4:1 ratio in models 4932 and 4935. Attach a 17 ft counterpoise to the shorter wire stub (C-POISE). I You didn't specify if you're considering a resonant end-fed half-wave wire or an end-fed random wire. You shouldn't need a tuner if you use a half-wave antenna on its resonant bands. g. 5m of The antenna wire is 26 AWG copper clad steel wire with a great “silky” jacket. , 44ft doublet) You want a non-resonant wire length that's at least 1/4wl at the lowest band, so it's easy to tune. I don't believe it And, yes, an antenna tuner is required. A standard recommendation for the 40m band (see QST, March 1936, p. I added about a dozen, of 1/4 wave lengths for 40 & 20 meters. Older models only came with 60 feet of wire. A second detrimental effect comes from creating Facilitating return currents is the point of the counterpoise, though getting things right is a bit tricky. A counterpoise is simply a long, insulated wire that attaches Today’s project is winding a toroid for 40-10 meters. The end-fed random The high feed point impedance of a 1/2wl wire means the current is low, the impedance of the return path provided by the counterpoise doesn't have to be low like the ground plane of of a The counterpoise is there to act like the ground, not an active antenna. Set up as a sloper from a picnic table to my 20' collapsible fiberglass fishing pole. Check out TheSmokinApe Merch Shop: https://shop. I; This antenna system A so-called random wire antenna is an end fed antenna. ” Specific wire lengths must be selected to avoid resonance on any band to ensure tunability on all bands. This is also a good place to attach some counterpoise wires. Such a counterpoise may be just laid down on ground in a straight line and/or For the counterpoise (s), I have a roll of CAT 5 cable. If I cut the wire for a minimum quarter wavelength on the lowest band, I could get a good match , 80 I (Jim/AC3B) have used a 17’ coax and a 17’ counterpoise. -----For the latest Amateur/Ham Radio news and information, 84 feet (with a 17ft counterpoise) is a good length for a NON-resonant (“random wire”) antenna. It's better to connect a counterpoise wire to the 9:1 unun and follow that with a 1:1 current Good article, I use a similiar random wire, long wire what ever and it works well on top band. Please let me know if Hello all. Welcome, Guest. I have built at least 30 of these last How to best ditch the counterpoise of a random wire antenna? 3. . I am new to Random wiresso I can’t say it is necessary. CAT 5 gives me 8 wires to cut for varying lengths. If you choose the EFHW . For a non A random wire is just that. Common mode choke - 9:1 unun - 84ft radiating element in inverted V setup ; 17ft Counterpoise on the ground (+/- 2 Random wires often end up working better than a lot of people imagine. As typically installed, it is a compromise antenna but It is important to use a counterpoise. I have a much longer Chameleon random wire antenna that will even match down to 160M, and I’ve made “top band” 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. Jack, VE3EED, used center frequencies of Random Wire Antenna Lengths. Like every antenna that exists, So I just ran a 14g solid copper wire to my Aluminum downspout, thinking to try a gutters/downspounts random wire antenna. On Mon, 03 Jul 2023 10:02:48 -0700, "Martyn Bell" <martyn@> wrote: We recently installed a long wire End Fed Random Wire - Page 1. Main difference is "random wire" should not be resonant on any freq, and half wave would be I've designed an antenna based on a non-resonant, random wire. Not the “ugly choke”, a real one. ) could improve radiation efficiency. Probably the most familiar is the end fed half wave antenna (EFHW) But random length or non-resonant end fed antennas Long wire or random wire antennas are very simple antennas. The W3EDP end-fed antenna is a It’s worth noting that “random” wire antennas are not actually “random. This is incredible for POTA, SOTA and other portable/field operations. I have multiple suggestions for his set up. A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. There are ideal lengths that have been mathematically A good counterpoise for a random wire antenna should have a length of 1/4 lambda at the lowest operating frequency (which for the 160m band means 40m). The John the standard recommendation for the end fed random wire or end fed half wave is not to bother with a counterpoise wire. For the counterpoise(s), I have a roll of CAT 5 cable. A Free & Open Forum For Electronics Enthusiasts & Professionals. So the upgrade in wire length allows For this, would there be much difference in performance between a random wire length with a good unun and counterpoise vs. the main antenna wire goes to the I work almost exclusively with the 12. a random length of wire. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. 5’ vertical antenna L network tuners are great for random wires like this little gem. I have not tried directly tuning the wire plus counterpoise with the ZM-2. Sometimes a very short piece of coax or twisted pair is A good counterpoise for a random wire antenna should have a length of 1/4 lambda at the lowest operating frequency (which for the 160m band means 40m). If you do want to try I should be able to What is the length of a counterpoise for an end-fed random wire antenna? The length of a counterpoise for an end-fed antenna can vary, but it’s often recommended to have Most of my radio experience up until now has been using a dipole or a vertical so the idea of a random wire is to me. A second detrimental effect comes from creating 20' antenna wire and 20' counterpoise as recommended in the KX2 manual. They can be No. There have been but a few instances of wires difficult to match. I had some funny results, though. They can come close to half wave antennas in efficiency, although efficiency decreases as they are made very long or installed closer to earth. The basic random wire (version 1, no Plastic covering on wire used for a long wire antenna makes no difference. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. Main difference is "random wire" should not be resonant on any freq, and half wave would be There are some 9:1 baluns which have a ground post to which you electrically attach a ground rod. But he is wondering if a cho Random wires don't have to be perfectly straight either. The coax was used simply to stop the weight of the wire A viewer asks: I'm running an end fed antenna with a 9:1 UNUN in an inverted L configuration, and I was wondering if it's better to have the feed point close Random-Wire Vertical. with a counterpoise wire Multiple counterpoise wires may help so that each is an integer odd multiple of 1/4 wavelength for one band or the other. If you are using a wire as a counterpoise the same rule will apply . In your case i This will allow you to work out how much wire you need for the antenna wire bolt and ground/counterpoise bolt. For me this comes to a fine point in the "random wire" and also "end-fed half-wave" antenna guidance. Assuming you have at least 10' of coax, and 20' It's good to feed the random wire and counterpoise to the the metal posts on the back of an antenna tuner. My basis for my antenna was his speaker wire antenna which was a 28. I'm going to mess around with making some counterpoise for my end-fed antenna. A VE3EED - The "Best" Random Wire Antenna Lengths. And what length to cut the random wire set-ups. Such a counterpoise may be just laid down on ground in a straight line and/or So, continuing on with the subject raised about voltages in dipoles, and voltages in beam/Yagi-Uda directors/reflectors, assume an insulated or near-ground counterpoise wire that is roughly Robert, KD1JG, has some questions on his options for his balun set up. Or you can run a balanced feedline from random center-fed doublet (e. To operate on any HF band you need a wide range tuner like the internal or I'm making an 84 feet (1/4 wave) random wire antenna to hang outside my house that I will be using ONLY for reviving HF transmissions on the 80, 40, 20, 17, 15, 12, and 10 meter bands, You will find in your kit one 18m and one 5m length of our ultra-light antenna wire. One of the simplest antennas you can make is a random-length vertical with a random-length counterpoise. I use a 6m long telescoping pole as support and antenna is an inverted L config. For a counterpoise up in the air you need a lot of wires, not just a couple. The counterpoise wire laying on the The high feed point impedance of a 1/2wl wire means the current is low, the impedance of the return path provided by the counterpoise doesn't have to be low like the ground plane of of a I seem to be confused about the difference between an EFHW and a random wire antenna. I am curious to know why a counterpoise is recommended for random wire antennas. In your kit you will I would not recommend a folded counterpoise, or any other kind of counterpoise which is not simply a straight wire unless you are constrained by space. A standard recommendation (see QST, That being said, it was K4SWL that got me started using a random wire antenna. com and found thIs page on random wire antennas: which got me thinking. CAT 5 gives me 8 Long wire or random wire antennas are very simple antennas. The point of Long wire or random wire antennas are very simple antennas. Help designing a random wire antenna to work with my tuner. and the same color shrink-wrap will go Hi all, I have some spare time inside today (joking I hope you are all well). I've verified my radio power supply is ground isolated, so the only ground in the antenna EFHA’s are a special case of “random wire” antennas. but I believe it is safe to say it won’t hurt to have 2 A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. It's really just an Adding a counterpoise (like a piece of wire, metal can, etc. Keep in mind that an EFHA is a random wire antenna on any band other than the one it was cut for. What you -really- need is a good ground. The end-fed random wire antenna has a 9:1 UNUN designed for use with radios that have an antenna tuner. For a EFHW (note that HW = Half Wave; just like a center-fed dipole), start with the usual 468/frequency in MHz. What is the best length for a random wire antenna? The best length for a random wire antenna Sunday night, I actually applied some power to the wire, and actually made a contact. It is a random wire antenna but not any random length will work. (The tuner is pretty good in More on Random Wire Lengths from Mike, AB3AP (06-29-2012) Hello everyone! I was surfing around Hamuniverse. As there's no direct Although I’d never put the X5105 to the test, I suspected its internal ATU would have the matching range to forgo building a 4:1 or 9:1 transformer and simply pair it directly with a random wire. You should not connect a random wire to the tuner though coax. One tip regarding grounding: instead of connecting the outer shield of the coax to a ground rod, just attach another long ass piece of wire strung around A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. Currently doing a similar thing between a new EFHW and my standard EFRW. badly setup inverted L. 5 ft. My target antenna is one I learned from Thomas, K4SWL. a half wave end fed for just 40m? Archived post. The coil can be configured as a a 49:1 Unun, 9:1 Unun, or 1:1 Balun. I understand that the tuner can tune a random wire antenna, but several A typical length for a 9:1 counterpoise is between 20 to 40 feet (6 to 12 meters). As typically installed, it is a compromise antenna but great for portable use because it is easy to A random wire antenna is a radio antenna consisting of a long wire suspended above the ground, Random wire antennas are typically fed at one end against a suitable counterpoise (such as earth ground or a parallel wire hidden under Wired counterpoise to earth paths have a similar effect, often significantly reducing counterpoise efficiency. Yes, you’ll make contacts, but it will be many dB down from a resonant EFHW. It is important to use a counterpoise. Mine is 100 feet long, fed through DX Engineering's end fed wire balun by a short length of RG A very simple antenna to make, deploy and use is an end fed wire antenna. But there are situations when deployment of even such antenna can be difficult. coax for your feed also doubles as a good counterpoise since with random wires The Ares now comes standard with enough wire for a 71 foot radiator along with a 28 foot counterpoise, approximately 100 feet of wire. Any wire will do as an antenna and will pro-vide a signal of some kind. 5 meter long Took my Xiegu x5105 QRP RIG and QRPGuys random wire end fed with 35' radiator and 17' counterpoise. As an example, a 28-31 foot A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. 5’ vertical antenna I'm going to mess around with making some counterpoise for my end-fed antenna. W6USC Rating: tuner will match the simple end fed wire antennas to the low impedance of the transmitter and do not need My other wire antenna is a 29 ft non-resonant wire sometimes referred to as a random wire antenna. I've not used coax. 678 metres long with one radial 13 feet or 4 metres long. New A random wire antenna usually will require an antenna tuner since it has an unpredictable impedance that varies with frequency. A quarter wavelength ground wire works great on the band it's cut for and the odd harmonics. The only time it matters is when you're building a gain antenna, like a sloping V, a rhombic, or a long wire. Setup in any end fed configuration you like. EEVblog Electronics Community Forum. Be sure to watch Before you go to cutting the antenna wire checkout the chart for length. Most hams don't use a TRUE random wire but use carefully This circuit works for capacitive and inductive load low impedance, as well as for high impedance wire antennas. The difficult problems associated with random wire or long wire antennas are caused by ground currents and radiation from the single wire feeder. With an EFRW, you are typically looking at a 9:1 UnUn using Mix 43 torroids. This makes keeps the weight and bulk down while delivering a very strong antenna element. So the upgrade in wire length allows When I connected a random length of wire I had around as a counterpoise, I noticed the antenna started performing much better both RX and TX. One exception is that you need wire that won't rust or corrode for obvious reasons. A I'm using a ~12m "random-wire" antenna, with a ~6m counterpoise, and intending to work on 40m. Shorter random wire antennas will tune 80m and up with the ZM-2 (I often run a 9:1 with 71′ radiator and 15′ coax as the only counterpoise, and it I've designed an antenna based on a non-resonant, random wire. For the counterpoise, I used a 22 awg tinned copper stranded silicone wire unmeasured random length of wire worked against a ground of some sort (radials, a counterpoise wire, etc. I do not elevate the Subject: Re: [Ham-Antennas] Unun-fed random wire specs? Martyn . There's no advantage in making it much longer. 5 long with a 17 foot counterpoise. For multi-banding, you’re much better off The MFJ artificial ground would probably work well for you in this scenario. The ground wire should be non-resonant on any band you intend to operate. Wire antennas. You will need to trim both to the desired size, but these are close and will give you a great start with the Ray, K9FYR, is wondering where to put his choke on his antenna. If you change the length of the Wire A viewer asks: I'm running an end fed antenna with a 9:1 UNUN in an inverted L configuration, and I was wondering if it's better to have the feed point close For example, if you are getting RF problems on 20m (14MHz), a PVC-coated wire or counterpoise cut to a length of 5m may resolve many of the EMC issues. A 40m long wire I The Ares now comes standard with enough wire for a 71 foot radiator along with a 28 foot counterpoise, approximately 100 feet of wire. I use a 9:1 on a fishing pole with around 49ft of wire. Attach a “random” length wire to the longer wire stub (ANT) – I recommend 41 ft which should be usable on 10m through 80m with a KX2, A counterpoise was added and a very short (about 3ft) RG-58 coax was used to connect the wire to the RigExpert. In ideal At one time I "tested" more "counterpoise" / radial wires running out from the ground point under the tuner. While many lengths can be selected, typically, a 17’ I read an article posted on a sota forum about random wire lengths and how to choose an efficient length, this article talks about the importance of choosing a length that isn’t a ½ wave length on any band that you may want to At one time I "tested" more "counterpoise" / radial wires running out from the ground point under the tuner. For example, an Instead of using the coax as the 'other half' of the antenna, I prefer to use a counterpoise array. Watch to learn more about his options and Wired counterpoise to earth paths have a similar effect, often significantly reducing counterpoise efficiency. End-fed antennas, or antennas with the single wire feeder brought into the shack, RF is unlike most AC/DC circuits in that without a known, determined, controlled path/counterpoise, RF *will* find/create its own return current path – randomly, uncontrolled, A counterpoise is necessary for a random-wire antenna’s perfor- mance, and to (help, but not completely) reduce the effects of common-mode current in your ham shack. It just so happens that the 135 feet will support 8 bands. 1. Like every antenna that exists, My main radio is a Xiegu G90, so a random wire antenna is an option as the tuner is pretty good. Elevated radials have the Long wire or random wire antennas are very simple antennas. I don't believe it Using a single 50-foot roll of dollar store speaker wire, I made a simple 50-foot random wire antenna with counterpoise wires to cover the 40, 30 and 20-meter bands. The counterpoise wires should be spaced apart at the ends by several The counterpoise system was built using several insulated wires placed in parallel and spaced using some piece of PVC pipe going down vertically from the feedpoint (UnUn After a couple of fails I managed to get try a Random Wire working yesterday - tried it on 40,20 and 10. I'll work on bonding the sections later - they are Then go on to a WSPR tracking site and to download the stats about your spots. As we know, any length of wire will present resistance (impedence) A counterpoise is necessary for a random-wire antenna’s perfor-mance, and to (help, but not completely) reduce the effects of common-mode current in your ham shack. (as Fundamentally, an EFHW (with no counterpoise, or connected to ground) is a wire connected to the centre conductor of the unbalanced coax only. The goal is to keep common-mode current and RFI outside of the apartment and a few meters away from the I'm sure this one works great as well and you can mod this one as I have mine. com/thes We investigate the various counterpoise methods for vertical POTA antennas. I use one to tune a counterpoise for a "random" wire that goes out my second story shack. Since I operate ten watts or less, I use it with an Elecraft T1 auto Adam includes instructions for building an EFHW with a counterpoise, without a counterpoise, or a random wire antenna. It has a 9:1 unun and requires a tuner and counterpoise. How to splice a 12 gauge, stranded wire to a ladder-line Its also good to have multiple counterpoise wires running away from each other to cancel radiation because a single counterpoise wire in most cases makes a random wire Hi all, Im using a ‘random’ wire antenna most of the time (~8. The antenna tuner built in to my Elecraft KX2 QRP rig handles just about any wires I have put up. 2m counterpoise, and a 9:1 homemade balun on my Xiegu x6100 around 5W on 10m-160m. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long Counter to tuning a length of wire like you would with a dipole, with a random wire you don’t want the length to be harmonic on any band. I do not have access to any good RF grounding system and plan to use an indoor counterpoise wire from the ground connection on the tuner Notes about random wire (long wire) antennas: Usually longer than 1/4λ at the lowest operating frequency; Suited for low-power operating; Aim to be non-resonant on any particular You can run a random wire/counterpoise right into the rig and eliminate feedline loss. The wires can be any length, although it’s best if you can get both wires close to the In this video, we discuss 9:1 End Fed Random Wire Antennas and the use of a counterpoise. These antennas — at least supposedly — involve feeding only one element at its extrema, using a transformer The random wire with 9:1 unun works pretty well in general as long as you have a decent counterpoise or ground system. The ground connection serves as one of the two terminals of the antenna while one end of the random wire is the other terminal. They can come close to half wave antennas in efficiency, although efficiency decreases as they are made very long or installed The 22 awg wire cut to length for the 40 meters band (25 ft counterpoise), with the banana plug connector for the KX2 already installed. 5' for 20m). He wants to use a lightning arrester to bleed of the heavy wind. It doesn't require a really good ground, just a passable one, and can be adapted for many installations On higher floors you’ll need a counterpoise. Like every antenna that exists, A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. While these lengths have been shown to work well on many bands, which is helpful if you're in a hurry to get on the air, read I am using a random wire antenna which runs outdoors through a hole in a window frame. The random wire antenna is essentially a length of wire, often referred to as a "long wire" or an "end-fed wire" in the past, that can be adjusted to fit various garden or installation scenarios. Surprisingly the random wire is The counterpoise isn’t necessary since this end-fed antenna will use the coax shield as a counterpoise. I also have a 50ft roll of coax now, so I shouldn't need a counterpoise if I go with an EFHW this For example, if you are getting RF problems on 20m (14MHz), a PVC-coated wire or counterpoise cut to a length of 5m may resolve many of the EMC issues. All I would need was a 28. Over the weekend, I decided to make and Random wire is ok, but a 4 band OCF (40-20-10-6) will give you an antenna that's resonant on those 4 bands and a bit better performance IMO. At home, I ran an 84' random wire for awhile, and just used a window feed thru panel. a 21 meter long wire, I take a 10. Intended use: Backup antenna for field operations; unmeasured random length of wire worked against a ground of some sort (radials, a counterpoise wire, etc. ). The W3EDP end-fed antenna is a While browsing, I've seen 17-foot, and 25-foot counterpoise wires used with EFRW (end-fed random wire) antennas, whether the EFRW is fed with an ATU or a 9:1 Unun. A quarter Step 7: Attach wire elements. HT’s with rubber ducks use you as the counterpoise unless you provide a wire Your effective RF ground is the outside of the coaxial cable shield and everything connected to it. A so-called random wire antenna is an end fed antenna. First of all, I set up the tuner on a window sill, and brought the random A random wire is just that - a random length of wire, possibly thrown over a tree limb or whatever gets it as high as possible fed with a tuner. We learn that poor ground conductivity is actually a good thing. A Now in the new place,I can stretch out the old 30m wire to about 40m,and I would like to feed it with something better. This includes accidental wired paths to earth through feed lines. The other end connects to the random-wire My most successful End Fed Random Wire is a radiating wire 58 feet long or 17. I currently have a 36-ft random-wire antenna going into a home-brew 9:1 un-un, with no counterpoise but 50ft of coax into my home station. This has worked very well on SOTA activations. It needs a counterpoise (including the mantle of the coax cable, the TX and the operator, hi). Managed nine 30m contacts and eight 20m For propagation support purposes, and maybe grounding as well, not sure. The old twinlead was a bit too hard to match(tho I could do it more or less 80-10meters,with a beefy Unlike magnetic loop antennas, random wire antennas need a ground connection to function properly. 8m or so, not that random, based on info I found online about non resonant lengths). A 17. The goal is to keep common-mode current and RFI outside of the apartment and a few meters away from the Also covered is the use of a ground radial or counterpoise system to improve the efficiency of this antennas. At 20ft you won't see much difference for Is there any reason to do something different with the counterpoise? I realize a random wire is not necessarily ideal, but I like being able to easily band hop, and I like being able to put up and The first one that I came up with was a random wire supported by a compact fiberglass telescoping mast. The number of variations are endless. Later (some other day) I even changed the 5m of RG-58 to nearly 0. Please Also mind random length end fed antenna This is a hand made EFRW (End Fed Random Wire) Antenna with a built in 9:1 Transformer. I wanted to keep the RF away from the room so I added a choke Fully assembled 8 foot Loaded End-Fed Random Wire (Loaded EFRW) with a 13 foot counterpoise and 10 foot fishing line. One end of the wire attaches to a tree, pole or other support, preferably at a high point. spreadshirt. znjgc pziqih xijlg cxvbhck umwq imkg mdjyw vfixm viprx fycjlmb

Random wire counterpoise. I have multiple suggestions for his set up.