Ideal random wire length. For a EFHW (note that HW = Half Wave; just like a center .

• Ideal random wire length If you picked the T140-43 option, you will see a lower SWR on the lower bands. Mine is 100 feet long, fed through DX Engineering's end fed wire balun by a short length of RG-213U to my station tuner. 5, 41, 58, 71, 84, 107, 119, 148, 203, 347, 407, 423 The Random Lengths Weekly Report, delivered every Friday, provides essential price data and unbiased analyses of trading patterns, plus reports of important industry trends and events. Long wire or random wire antennas are My random wire was 18AWG speaker wire. There’s now no doubt in my mind that a random wire can be an effective antenna. Finishing/tinning and putting two wires in one hole can be awkward. , the mid-setting of Local-Normal-DX) is best used with a random length of wire no more than 20-25 feet in length. e. In my mind, this is a pretty serious misuse of the term ‘ random’. He was, of course, 599 here, but he gave me a 589. The wire you describe sounds really heavy. Lots of talk about the lengths of the wire to avoid on the various bands, but not much about feed-line length. Usually people use random longwires for multi-band operation. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. Languages. Since the design frequency is "a lot of them", the strategy of a random longwire is more or less to give up on making the wire suit any particular frequency, and just deal with the mismatch with a tuner. I would like to operate on the entire 80m phone portion of 3. The the best lengths as long as your wire is at least 1/4 wavelength. 1 Mtr, 18. 5 flaws occur per . However, it is not an optimal antenna design and I plan on deploying a 80-10m end-fed half wave this weekend and would like feedback on the starting length for wire. 84 feet (with a 17ft counterpoise) is a good length for a NON-resonant (“random wire”) antenna. Now wasn't that one simple. They can come close to half There is no consensus on an ideal-length doublet. This is considered a random wire end fed antenna, not to be confused with a half wave end fed antenna which uses a 49:1 or 64:1 unun and a wire that is The length of the wire needs to avoid any (preferably all) of the combinations of half wave lengths and their harmonics on ALL the desired bands of operation. It is a very simple antenna consisting of two lengths of light-weight wire 42 feet long each. 5 Mtr, 38 Mtr. . Also, if you want to receive New Zealand from the UK you want the antenna to receive from dead north. The radio. * Note about antenna wire selection In what follows I'm referring to stranded, insulated copper wire (for the antenna and counterpoise wires), but if you prefer using solid and/or bare wire, it will be ok too; things will change in Hi, been playing with antennas on my SOTA activations, in summer linked dipole, in winter a EFHW trapped for 3 bands. Random Wire Antenna: HF (3-30 MHz) Length varies: Loop Antenna: HF to UHF: Varies with design: Yagi-Uda Antenna: VHF/UHF (30 MHz – 3 GHz) Various, based on elements: Quad Antenna: While a straight long wire is ideal, long wire antennas can have bends or sloping sections as long as they are properly tuned for resonance. I don’t believe it’s as pronounced as a beam or anything. Length (m) Length (ft in) Notes; 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 frequency; Requires a 9:1 unun; A counterpoise (or multiple counterpoises) is recommended; I am curious to know why a counterpoise is recommended for random wire antennas. If building your own, however, keep in mind that there are some radiator lengths to avoid; check out this article to discover some of the best (and worst) random wire lengths. Both long wire and random wire antennas are "random", because you use them over a wide frequency range and the lengths cannot be specifically For those operators who like to experiment, of the following lengths wire can also be used: 49, 55, 77, 92, 102, 141-148, 171, 203, 218, 268. This is a 200-2 core, which is ideal for the 40m to 10m band. The The "Best" Random Antenna Lengths. At 20ft you won't see much difference for NVIS until it's long enough to act as a traveling wave (long wire) antenna a wavelength or more long. 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. Output With the PL-660’s antenna gain control set to “Normal” (i. 3%; CSS 4. In message. This was achieved using a length of paracord over a You want a non-resonant wire length that's at least 1/4wl at the lowest band, so it's easy to tune. There is a An end fed wire will have a very high impedance. 5' random wire is best. txt) or read online for free. I added about a dozen, of 1/4 wave lengths for 40 & 20 meters. at 40m what is the ideal length of a RANDOM WIRE ? TO TUNE ON ALL BANDS 160M TO 6M ??? Ian Jackson 2012-05-22 12:45:30 UTC. Long wire or random wire antennas are very simple antennas. 5m or, better, 17. 11 m. There are some charts for optimal lengths of EFW, but I just go for length to use as little inductance as possible. Four variation of a random wire antenna with a length of 18. How long should a 9:1 counterpoise be? When the ALK is divided by the Frequency (MHz), the adjusted length is produced. 56 meters is the ideal Random-wire antenna for the mix of frequencies actually used today. The graph in Figure 7 has been produced with data generated from 4NEC2 antenna modelling software for Technically a true "longwire" needs to be at least one wavelength long, but Hams commonly call any end-fed wire a longwire or random wire antenna. I 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. The PackTenna Mini Random Wire Antenna combines a 9:1 UNUN, winder and antenna wire in a compact unit that is quick to set up and take The AH-4 is commonly used to tune "random wires" from the single terminal output. Here is a handy chart for determing 1/4 wave verticals, 1/2 wave dipoles, and full wave loop lengths. Lengths mentioned a lot: 7 Mtr, 9 Mtr, 16. I'm seeing some conflicting information about critical design parameters. These are going to be the two halves of your dipole antenna. 075 to 10. Longer wire is always more 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 You can see a table with wire lenghts to avoid and another line in green beginning with "REVISED:" for good random wire lengths. The radio plays a role in determining the ideal length as well. Always good to keep limitations in mind. A random wire antenna will be anywhere between 50 Ohms (for a quarter-wave) to several thousand Ohms (for a half-wave) so the ideal matching will depend on the wire length and frequency. doctordialtone Member. 7 meters) long random wire antenna. A 49:1 or 64:1 toroid core unun with an end fed wire about 65 feet will give low swr on 40, and harmonically related 20, 15, and 10 meters with no tuner. I made a "random" wire antenna and cut it to exactly 74' as per the "golden lengths" advice on the websites outlining the perilous lengths. Directional effects will increase between one or two wavelengths and not increase much after two wavelengths. You have two choices: extend the current wire length with additional wire or take off the existing wire by Hello all. 56 m) for the amateur radio HF How long is an 80-meter end-fed antenna? An 80-meter end-fed antenna would ideally be around 132 feet (40 meters) long for resonance. I Webiste- https://udel. However, neither is very efficient, and both can have severe problems with RF in the shack and local noise pickup. I agree that a higher random height that is not 1/2 wavelength related will not give ideal compared to another with 10ga wire, the thicker one would have slightly more band width. 300 MHz; SWR bandwidth at 1. One end of the wire attaches to a tree, pole or other support, preferably at a high point. $\endgroup$ – rclocher3. It The "Best" Random Wire Antenna Lengths Random wire lengths you should and should not use! Jack, VE3EED - SK; Yaesu Serial Number and Date of Manufacturing Decoder; Panadapter Yaesu FT-817, 897, 857 RTL2832u out IF MF 68,33 Mhz; 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple; 50Mhz 6m Beacons; Hola CQ The Gabil GRA-7350TC Rooftop No random wire will achieve that. 0 stars Watchers. At one time I "tested" more "counterpoise" / radial wires running out from the ground point under the tuner. Interesting idea. I have proven the following to work as needed in my filed operations and some fixed use antennas in the garden. My solution was simply to use some scotch tape every couple of inches to The ideal height for an EFHW antenna depends on factors such as frequency, terrain, and nearby objects. But it's even better when I "seriously" listen to seat back, or possibly lay down (my bed is near my desk), so a decent length is pretty much required for that. So random wire antennas aren’t very random at all, they are just carefully Here are some “ideal” lengths for a random wire antenna, given in both metric and imperial measurements: 29 meters / 95 feet; 35. I am planning a non-resonant end-fed using a Palomar Engineers 9:1 unun with a wire length of 135 to 138 feet for 160-80-40-20-17-15-12-10 meters (based on RadioReference. 1 A “random length” wire, the length of which is sometimes carefully selected to be non-resonant on any of the bands of operation, so it really isn’t very random. I will start with probably the simplest antenna you could think of. I was only thinking about the 49:1 due to the random high The type of wire makes very little or no noticeable difference at all at HF frequencies, so you can use anything so long as it can support it's own weight. 0 forks Report repository Releases No releases published. That flat height is ideal for antenna that is purposed to receive as well from front and If your wire is short, it might have trouble with 160. 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. The antenna Subject: Re: [Ham-Antennas] Unun-fed random wire specs? Martyn . 7 mtr. 0 feet ) Suggested starting length: 7. The conventional wisdom is that the 9:1 random wire antenna will be somewhat less efficient as compared to an end fed half wave. Portable - 1m20 (4 feet). Last updated on 2024-08-27. Assuming that the number of flaws is a Poisson random variable, what is. 7 Mtr, 27. Nevertheless, the Internet is a beautiful source of inspiration. I read that the counterpoise should be shorter, and should also feature impedance. If the piece of wire is then cut exactly in half, what are the mean and the standard deviation of the lengths of the two pieces?. Longer wire is always more Here’s a list of recommended lengths of wire to use with a 9:1 unun. Permalink. 5m or better 17. Packages 0. no. #hamradio #hamradioantenna #antenna Link to the FireStik SWR We hooked my Electraft KX2 to both the PK Loop and to a simple random wire antenna. On Mon, 03 Jul 2023 10:02:48 -0700, "Martyn Bell" <martyn@> wrote: We recently installed a long wire antenna for our club, it's approximately87m length and slightly sloping with a 9:1 un:un and no earth. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. The current one doesn't cover 80m, and I'd like to see if I could add that band. Can anyone help me finish this project? Help me Diagnose/Repair 9:1 Random Wire Antenna? Random wire antennas are the same as long wires, but often much shorter. Just have fun and try I have a Palomar Engineers 9:1 HF Unun for non-resonant wire lengths and trying to figure out what length of wire to start with for 160-10m. All antenna lengths in the information below are in feet and are the results based on the standard formula Wire Lengths for 9-1 Ununs - Free download as PDF File (. The other end connects to the random-wire connector on a A simple discussion on antenna wire lengths, feedpoint impedance and which balun or unun to use. The BNC connector is a DigiKey part #A97553-ND. Informs of how narrow (critical) is said length. This compact wire antenna is ideal for SOTA activations, camping, backpacking, and travel. My rule of thumb is use at much wire as possible and without doubling back a direction, so X, Y, and Z axes only once. View license Activity. The random wire with counterpoise (version 2) is a great option A very simple antenna to make, deploy and use is an end fed wire antenna. The "Best" Random Wire Antenna LengthsRandom wire lengths you should and should not use!Jack, VE3EED - SK Updated 07-08-2021 I have proven the following to work as needed in my filed operations and some fixed There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. The problem occurs when the wire ends up being a half wave multiple on one of the bands you would like to operate on. So if you have a 175 foot end fed wire antenna it would be a long wire above about 5700 kHz, and a random wire below that point. Just make it as long as possible. No packages published . 35 ft ~ 1067 cm appears to feature some impedance, at least for the In my opinion, the ideal wire length will be slightly different for everyone in practice. Longer wire antennas can provide too much signal to the receiver causing the signal to be reduced compared to using other antennas. And what length to cut the counterpoise to. You might do better with a counterpoise or other "earth" ground. 6 - 4. Mike Markowski (AB3AP) does an excellent job of explaining both the theory and practice behind random length end-fed antennas. It is also known, that very long random wires do not always give better results. 3 m ( 23. Feedline Lengths: The feedline length is also an important part of a "friendly" antenna design. Now playing with random wire antennas so started with the 84 foot wire and the 17 foot There are excellent resources out there that describe ideal heights and configurations for any given wire antenna suspend random wire from ground to its full length. Broad band random wire antennas are a huge compromise but they have their place. Technically a true "longwire" needs to be at least one wavelength long, but Hams commonly call any end-fed wire a longwire or random wire antenna. This page contains a table, but it's in The length of the wire needs to avoid any (preferably all) of the combinations of half wave lengths and their harmonics on ALL the desired bands of operation. A 9:1 balun is sufficient for a random wire. I've been working with end-fed "random" wires as quick and easy antennas for transmit and receive while traveling. "tuner"), and employ a proper counterpose system. Low visibility: With their simple wire design, end-fed antennas are ideal for stealth installations, as they can easily blend into their surroundings. Tolerance: Width to either side of each center point. For 40/30/20 I'd use about 40ft it's not critical. 3. I don't believe it made much difference. The other end connects to the random-wire connector on a In an effort to better understand the performance of my ft817 and the ZM-2 ATU, I’ve been exploring different random length wire antennas while camping. I read an article posted on a sota forum about random wire lengths and how to choose an efficient length, Determining the Ideal Length for Your Random Wire Antenna When it comes to the length of the random wire, there are several recommended options that have proven to be effective. Wire lengths for the 4:1 ratio in models 4932 and 4935. Don’t worry about the total length of the antenna. Such an antenna is not ideal – the ground losses reduce the efficiency – but it was adequate to get started on the band. They can perform OK (my current hf antenna is an 84' random wire), but the signal pattern is different for each band, and they are potentially lossy, with lots of local environmental interactions, tuner losses, etc. Cheaper radios can overload with longer lengths of wire. I didn't realise that they actually sell it as a cable length meter. I'm guessing these lengths avoid impedance extremes. The number of variations are endless. 1 to 7. The random wire with a unun is my favorite, but I still use the hamsticks and wire dipoles in some situations because they offer better performance. Also mind random length end fed antenna requires good grounding or counterpoise (best done at the 1:9 Find step-by-step Probability solutions and the answer to the textbook question A piece of wire is cut, and the length of the wire has a normal distribution with a mean 7. 26 to 27 meters - 85 to 88 ft. Ie. Each weekly 14-page issue contains prices for For a certain type of copper wire, it is known that, on the average, 1. If you're Simply use your own method to attach a random length wire, much if you can't get the lengths exact at the begining of this article or you don't have the ideal amount of real estate required for the longer antennas. Help designing a random wire antenna to work with my tuner. The idea is that some lengths just won’t work well on one or more bands. The NEC has rules for antenna wire size depending on length, you might look that up if you want the The conventional wisdom is that the 9:1 random wire antenna will be somewhat less efficient as compared to an end fed half wave. Current solutions shown in text window. This is true if the length of the random wire is significantly shorter as a function of the A random wire antenna is a radio antenna consisting of a long wire suspended above the ground, and then selected a compromise among all of them as an ideal work-any-band length of 74 feet (22. Accuracy to 1 centimeter (0. Random Wire Antenna Length Calculator; Wire Antenna Length Calculator; The wire was feed right of the match and it was random length. 67 feet ) Likely range of lengths: 7. probability, in 4 significant figures, that no flaws occur in a certain portion of wire of When you are talking about doubling the length of the long wire any results will be dependent upon the frequency (wavelength) you are receiving. The ground connection serves as one of the two terminals of the antenna while one I have a gang box full of random wire lengths for a big pull in multiple conduits. just use any length of wire and as long as possible. $\begingroup$ @Phil_12d3 Usually when one talks about random-wire antennas, one talks about end-fed wire antennas. The botton two sections of the calculator list the ALK and element lengths for 1/2 λ Dipole, 1/4 λ Vertical, and 1/2 λ, 1 λ, 3/2 λ, and 2 λ Single Wire End Fed lengths. Random Wire Antenna Lengths. There is no right answer to your question. My $36 Raddy RF750 came with a 9 ft. The wire used Ham Radio HF/VHF Antenna Lengths Chart. millimeter. Typical length of each wire with 12 cm ( 5 inch ) tail: 7. Single Wire/End Fed Antenna description. The length of the counterpoise is not critical. There is no optimum length, by definition. JACK, VE3EED ===== More on Random Wire Lengths from Length: Center point of each non-resonant segment. edu/~mm/ham/randomWire/& https://udel. 25 to 24. A random longwire is just that, a random length. It is also known, that very long random wires A random wire antenna length calculator takes the desired frequency range (in MHz) and suggests wire lengths that are less prone to resonance issues. 68m. 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. Your Account Database Wiki Broadcastify Wire Lengths: Random Wire Antenna Lengths . Have fun! I've built my EFHW 49:1 transformer and am currently trimming the wire length down to bring it into the resonant frequencies. Changing wire length of antenna. Even number quarter wave lengths (half wave multiple) do not. 2 m and a standard deviation 0. There's no advantage in making it much longer. 68m In addition to the length of the antenna, you will need What is the length of the wire in a 49:1 end-fed antenna? The ideal height of an antenna above the ground depends on factors like frequency, radiation pattern, and local conditions. 6-4 MHz For 3. Quick impedance calculations indicate that a 58 ft "random wire" antenna could work for this. 73. 3 m ( 24 feet ) Wire length change for 100 kHz: 4 cm ( 1. I heard there is a way to ohm the wire to find the length of the reel. github. Experiment and see what works best for you. I've been a ham for 60 years now and the axiom that has always been proven true to me is that "There is no substitute for wire in the air". I bought a combo 4:1 and 9:1 balun (unun?) made for long wires but I can't seem to find the correct length for the long wire. You can use wire antennas of virtually any length with radios like these: Sangean ATS-909X, Tecsun PL-880 and Eton Grundig Edition Satellit. So if I use a 21 meter long wire, I take a 10. I assumed it was a 'normal' micro-ohmmeter and you do the math to get the length. However, the list has been revised and is good for wires as long as 500 feet. edu/~mm/ham/Presenter- Mike Markowski, AB3APJoin us live every Wednesday & Thursday for a new ses And this is a longstanding write-up on why 22. Over the weekend, I decided to make and test another long/random-wire antenna. This is true if the length of the random wire is significantly shorter as a function of the wavelength. Adding The resultant loop was approximately 70m in length and strung up in a horizontal sloping rectangle, loop ends entering the upstairs shack window and fed directly from an old KW ATU using balanced outputs. The four elements are interactive. As typically installed, it is a compromise antenna but great for portable use because it is easy to pack and easy to install. 0 MHz, the approximate lengths are 136 to 123 Index Terms: Average wire length, wire-length estimation, gate sockets, Rent’s rule, stochastic wiring distributions. Google “random wire antenna” for some design ideas - but the short answer is get some 20-24 AWG threaded copper wire The conceit that goes with random wire antennas is that they amount to taking a random chunk of wire, stringing it up in the air, and using it as an antenna. Hi Pete, Good article, I use a similiar random wire, long wire what ever and it works well on top band. 34 to 35 meters - 111 to 115 ft. It's better to connect a counterpoise wire to the 9:1 unun and follow that with a 1:1 current choke on the coaxial cable between the unun and the rig. If you’re going to use this kit for 80m, then you should ideally have a random wire length of 12. 39 inches). A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. For good 10 through 80 meter coverage, you’ll find that a non resonant wire of about 74 feet is ideal. 5 meters from the 1:9 Transformer. A Simple, Very Effective Random Wire Antenna for Shortwave and AM Broadcast Radio-by RadiodogHi there, radio friends! Here's a thorough step-by-step of the r Here is a list of favored Dipole lengths:* 40 to 41 meters - 132 to 135 ft. MM6JBN when looking online for L/W antennas one keeps popping up as a 'quickfix' if you have an ATU the good old random wire seems to be A random wire antenna [1] is comprised of a long wire above ground that is used to transmit and receive signals. And 10' is WAY too low. The match was built on a pine board with just a coil, variable cap (365 broadcast type) and alligator clips for configuration of the tuner and tapping the coil. As you can see, a 29' or 35. Generally, A disadvantage of a random wire antenna is that its length may not be resonant on the desired frequency, leading to less efficient operation. They provide a good compromise between performance and ease of tuning. INTRODUCTION HE dominance of interconnect parameters on the performance of deep submicron and nanoscale integrated circuits and systems is becoming ever more crucial with technology scaling [1]-[5]. The PL-660 & similar are manufactured to be The length of the counterpoise depends on the antenna wire or. very few of us regularly experience ideal conditions for HF or AM radio listening box of electronics Unlike magnetic loop antennas, random wire antennas need a ground connection to function properly. monic effect of the length of the wire and how that effects the various bands on which you wish to operate. A long wire antenna requires a length greater than a quarter-wavelength (λ/4) or half-wavelength (λ/2) of the radio waves (most consider a true long wire to be least one wavelength), whereas random wire antennas have no such constraint. (That dipole The key is in the wire length. Joined Apr 18, 2009 Messages 6,327 Location CT Technically a true "longwire" needs to be at least one wavelength long, but Hams commonly call any end-fed wire a longwire or random wire antenna. In other words a 66' end fed half wave on 40m will be more efficient than a 20' random wire on 40m. When installing and using a random Calculate the lengths that should be avoided when making "random wire" antennas. Probably the most familiar is the end fed half wave antenna (EFHW) But random length or non-resonant end fed antennas A random wire antenna length calculator mcandre. This can be enhanced by dropping wire vertically over the branch to the ground . The name says it all. RANDOM WIRE SHORTWAVE ANTENNAS. JavaScript 67. The tuners commonly available are not very good at tuning high impedances, unless they are specifically designed for this purpose. 65 feet sounds about ideal for 40 meters. It includes a table Many people use what is referred to as a "random length" wire antenna for HF, quite effectively. Readme License. Plastic covering on wire used for a long wire antenna makes no difference. So the actual ideal length varies greatly depending on the The first step is to figure out a way to manage carefully wiring 3 lengths of wire around the coil. The reason we need to avoid multiples of 1/2 wavelengths on a random wire is the impedance of an end-fed 1/2 wave dipole is extremely high (2000 Ohms or more), and the tuner cannot match that impedance with its internal inductors and capacitors. My 18AWG wire was too heavy, IMO. 5 long with those are tried and true, just, if you want a bit of radiation For that reason I purchased a Sotabeams Bandspringer. [3] Hence ~ 74 feet The simple single wire length of the random-wire antenna acts as both feed line and antenna and is directly connected to the transmitter. Post by Joe. but. I read that unlike the main antenna radiator, the counterpoise should be shorter, and should be designed at a length that will not propagate well, that it should feature some impedance. In my experience, I normally use the half length of the antenna wire. 9%; Footer Directional characteristics of random wire and long wire shortwave receiving antennas are dependent upon the antenna length, height above ground, received frequency and directional orientation of the antenna wire. EFHW might get you a little better efficiency at the expense of bands and more wire-length fiddling required, depending on your local conditions. It calculates lengths I have been experimenting with random wire antennas, and it seems as though it's not completely random. The best length for a random wire antenna can vary, but a common recommendation is to use a length that is a multiple of half-wavelength for your desired frequency band. When you connect a 1 wavelength loop, Ever since playing with the ubiquitous 9:1 unun there came a point in time when I wanted to find out how lossy this antenna system really is when deployed with a seemingly random wire length. If you search for "best random wire antenna lengths" there are some good sites that explain everything and give tables of wire lengths for different band combinations. 2. I'll get a 9:1 unun,and use a suggested random wire length to avoid half-wave and it's multiples then,that sounds like the best things I can get out of this setup. pdf), Text File (. VE3EED the "Best" Random Wire Antenna Lengths * 29, 35. Updated 07-08-2021 by ve3ips. It depends upon a couple of factors. This antenna is able provide me almost the entire HF bands with the exception of the 160m due to the Random length end-fed antennas are simple, effective HF antennas if you calculate the proper wire length, use a wide-ranging antenna transmatch (i. I've got the 9:1 Balun installed. If it isn't end-fed, then it's usually near-center fed and becomes a dipole antenna instead. 8%; HTML 27. As an example, a 28-31 foot wire will typically allow 40 thru 10 meter coverage and a 43-50 foot wire will provide access to 80 thru 10 meters. 65 feet is a half wavelength on 40 meters. My target antenna is one I learned from Thomas, K4SWL. 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 Much has been written about the optimal length of a random wire antenna (sometimes called a long wire antenna), some of which is contradictory. the mean number of flaws in a portion of length 5 millimeters? What is the . Multi-band capability: Some end-fed antennas, particularly those with random A random wire antenna is a radio antenna consisting of a long wire suspended above the ground, and then selected a compromise among all of them as an ideal work-any-band length of 74 feet (22. There are ideal lengths that have been mathematically determined to be best for random wires. For typical tuners built into a rig, these are the worst lengths and you want to be as far from colored bands as possible. The document provides recommended wire lengths and typical SWR values for Unun models 9130, 9132, and 9135. One end goes straight into the rig, often with no feedline, and the other end in the air attached to something as high as you can find. What is the power rating of a 9:1 unun? Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Many people use what is referred to as a "random length" wire antenna for HF, quite effectively. 56 m) for the amateur radio HF bands. The “Best” Random Wire Antenna Lengths Random wire lengths you should and should not use! Jack, VE3EED – SK. Commented Nov 25, 2019 at 14:40. But I am unsure which counterpoise length to select. One exception is that you need wire that won't rust or corrode for obvious reasons. It came with two wires joined together, so I split them and doubled the length by splicing them end to end. So, I put two holes on L1 ground side. You won’t be trimming or adding Generally, the longer and higher the shortwave wire antenna the better. The "Best" Random Wire Antenna Lengths Random wire lengths you should and should not use! Jack, VE3EED - SK; Yaesu Serial Number and Date of Manufacturing Decoder; 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple; Drake TV-3300-LP - A Peek a Boo Inside; Xiegu G90 Power Draw on Transmit Test; End Fed 9:1 Magic Wire Lengths I am planning a non-resonant end-fed using a Palomar Engineers 9:1 unun with a wire length of 135 to 138 feet for 160-80-40-20-17-15-12-10 meters This isn't quite like the normal quarter wavelength verticals where you need radial fields to act as the In an end-fed random wire, the max current (and therefore the The fact that the wire length is only 41 foot in length, this means that it is about a 1/4 wavelength at 40 meters. When I am a technician interested in building my first antenna. This is a quick way to add an antenna to radio equipment. I read an article In an effort to better understand the performance of my ft817 and the ZM-2 ATU, I’ve been exploring different random length wire antennas while camping. A random length of wire fed directly from the output of your transmitter (Fig-1). Safety Considerations. I choose a 30m long wire with a CMC installed 6. I don't use a counterpoise. As typically installed, it is a compromise antenna but great for portable use because it is easy to Random wire lengths you should and should not use! Updated 07-08-2021 by ve3ips. 5 meter long counterpoise. Also note that the best performing “random” wires aren’t random at all. The low angle azimuthal radiation pattern of an ideal half-wavelength dipole antenna installed 1/2 wavelength high and parallel to the Earth is a figure-eight at right angles to the antenna. Long wire or random wire antennas are A long wire is inherently not ideal. The impedance of a end fed wire can be anywhere You may use 450ohm as the feedpoint impedance then for the sim. (2. Resonant 80m End Fed Halfwave Antenna With Counterpoise - Questions. 450 ohms is the characteristic impedance that a 9:1 unun connects to the wire end with 50 ohm coax at the other side. I drove an 8'copper ground rod below the Balun for static drain and lightning protection. 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 You can see a table with wire lenghts to avoid and another line in green beginning with "REVISED:" for good random wire lengths. There are many lengths of Your effective RF ground is the outside of the coaxial cable shield and everything connected to it. It is a random wire antenna that is 29. 2 watching Forks. 22 m ( 23. I could match 80 through 10 meters. 5 inches ) Tuning range with 12 cm ( 5 inch ) tail: 10. On the HamRadioHelpGroup mailing list, there was a related discussion about the “almost random” wire antenna. Random wires and long wires are relatively noisy compared to dipoles and loops. It receives signals better from opposite direction. create transformers for random wire and dipole antennas. Hot A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. about 15-20 meter long if I use a 41 meter long antenna wire. For a EFHW (note that HW = Half Wave; just like a center have an homebrew end fed antenna just want to ask if I use Today’s project is winding a toroid for 40-10 meters. 5 : 1 : 250 kHz A random wire likely wont be tuned for the band and reflect a lot of that power back into the rig and As it is most likely that the angles / positions of those two wires you want to use won't really come near the ideal groundplane configuration the best idea is Unless that wire is proper length for the frequency you are It's fine and dandy to sit on my chair in front of my desk. One of the most popular lengths is 71 feet, which is said to provide good coverage from 80 Wire lengths for the 4:1 ratio in models 4932 and 4935. Use same construction techniques as in above for supports and connections. It is a TE Connectivity AMP With some of these designs we often see L1 and L2 wires twisted together for the length of L1. Stars. . I want to explore HF bands, 160m - 6m. Simply cut two equal lengths of stranded copper wire. The literature is a bit mixed on radials for random wire antennas with remote tuners, such as the AH4. If you’re going to use this kit for 80m then you should ideally have a random wire length of 12. Some lengths appear to work better than others. I also do SWL, the tuner helps with that, too =] To model this fluctuations that occur in the twist pitch, it is better to consider the twist pitch as a stochastic function ‫‬ ࣽ (ℓ), where ℓ ∈ [0, ℒ] is the wire arc length and ℒ The most widely used formula to calculate the approximate overall length of wire required for a dipole is: 468 / frequency (MHz) = length of wire in feet. 5 meters bands, which makes them ideal for a multi-band random wire antenna. A so-called random wire antenna is an end fed antenna. One length serves as the antenna and the A basic rule of thumb for "random wire" antennas is: At least a quarter-wave long on the lowest band you want to use, and not a half-wave on any band you want to use. I. The length of a "random wire" antenna has a direct impact on the impedance present at its end for a given frequency. io/fluke/ Resources. Odd number quarter wave lengths work very nicely. As I understand it, as your wire length gets to be multiples of the frequency wavelength longer (ie, on 10 meters), the antenna becomes directional in the direction the wire is pointed. mpcpem vxag mnaxac vehex glkbyq pnctbq jyp gfyazz vdkn rzlv