20m spiral loop antenna The following is an article which I wrote and was published in the February 2013 edition of the Central Coast ARC "Smoke Signals" magazine. It can also choke off unwanted RF currents flowing down the shield of a coax line. 20m 1. You can see t I am in the planning process for a magnetic loop antenna, and also have a Comet CVBA-500 capacitor. My delta loop will adequately tune on 20M, 17M, 15M, 12M, and 10M. In this article we selected the best seven delta loop antenna projects for the 40 meters band chosen from our full list of 7 MHz Delta Loop Antenna dedicated page, we suggest you to visit. J. In Figure 1, a plot of a planar Log-Periodic Spiral Antenna is shown. 2 Home Made HIGH POWER Magnetic Loop. It turns out that we can use the two twisted wires at the end of the diamond spiral as a tuning stub. 5MHz) loop (or frame) antenna has been really popular, and that there are loads of other radio To begin with, my design goals was to work 40m and 20m since those are the two primary bands I use for DX communications. [3]: F W Grover, "Formulas and Tables for the Calculation of the Inductance of Coils of Polygonal Form" Scientific Papers of the Bureau of Standards, Vol 18, p753 Wall Loop for 20m (QRZ. Magnetic Loop Antennas for The Radio Operator with Limited Space pt. 40m vertical dipole at 20m; 10. nonstopsystems. But resonance of the loop does not exactly correspond with lowest impedance. of 1/2" pipe you will need about 16pf of capacitance to resonate the circuit on 20m Most caps when fully open have a small amount of capacitance (mine has 12pf) plus there is some stray in the overall loop. So, my "longer" loop is about 1. 1. However, it also requires retuning quite often in order to stay on-band. Having the tuning knob on top also would allow dirt and water to enter the housing. The EZNEC program (and ELNEC) are commercial programs that may be M0AWS 20m Band Delta Loop Antenna – 2D Far Field Plot. 3 1. Several ham radio operators adopt delta loop wire antennas and array of delta loop antennas during their portable operations, being very easy to build and set up. Inspired by the mini-X-Q design, a modified 10m delta-loop was built, enhanced with a 1/4 wave shorted stub for 28 MHz using 450-ohm ladder line. 60 broadband antenna was featured in two trade journal articles. “The second characteristic of this loop antenna is that it is a high impedance loop, which might appear counterintuitive. In part one of this series, I covered the use of one brand of commercially available, small Best solution is with an antenna tuner for impedance matching. Reply. The consequence of this for your antenna is very small bandwidth. info real-time signal reports from stations that spotted my transmission. 240 MHz verall wire length roughly 1/2 wavelength, feedpoint 25% from end, The dipole antenna, developed by Heinrich Rudolph Hertz around 1886, is an antenna with a center-fed driven element for transmitting or receiving radio frequency energy. Loops. Although TASH sounded somewhat derogatory, it should have made the antenna Magnetic Loop Antennas – a brief theory and a practical antenna for 3. loop antenna photos. However, what I can verify is that, running about 200 watts to a single loop antenna from M2 has netted me 122 grids on Homepage van Maarten Ouwehand PG1N. 15m patterns (6 wavelengths) On 15m the antenna is more than 1/2 wavelength above ground, and we start to see minor vertical lobes, in addition to the expected Multiband Loop Antenna Project by Gary Marbut, K7GMM and Ty Marbut, W7TYY. com/radio/ If you like my videos, please subscribe here: 20m Loop Antenna by Harry Lythall - SM0VPO. Tuned SINGLE Loop with Coupling Loop. 25 wavelengths on 80 meters (2. Ideally, a loop antenna is designed to be portable, easy to So if my large loop is 5 feet diameter x 1/5 = 1 foot diameter of small loop; Larger main loop for lower frequency. incl. This loop is usually designed to operate on a specific wavelength of radio waves, and its 80m Horizontal Loop for Field Day. This limits the range you can Loop Antennas. I operated on FT8 so I could monitor where my signal was being received by using the PSKreporter. On checking the data sheet (downloadable from the Comet web site), I notice that the maximum Just modify the area of the feed loop by bending the wires to a smaller or a larger area. Clearly, that same 5 watts from the 20m short vertical dipole & monopoles- SM0VPO-style spiral loops (80/40/20) Note that in the Slinky Loop antenna discussed in ref. (160m/80m), while really tailoring the performance of the loop to be a 4-wave loop on 40m. 12m n/a 1. 5 A 42m Horizontal Wire Loop Antenna for 10m, 15m, 20m and 40m. 5 on 40m, 5 on 20m and 10 on 10m) and is installed between 30 to 40 feet in the air. And for the most part its true. All the loops described here were designed and built by myself. Loop antenna calculators suggest that a loop of that size can be tune from 40 to 10 mtrs with a variable capacitor of 10-180 pF. Datasheet. diminutive magnetic loop antenna can really perform in practice compared with large traditional HF antennas. double loops. In fact, if you desire operation from 500kHz to 30MHz, you might want you antenna to be not resonant. 1 wavelengths, where the current is approximately constant around the loop. construction of wire loop antennas. 1 1. The objective of this article is to disseminate some practical information about oftentimes outperform any antenna type except a triband beam on the 10m/15m/- 20m bands, and will at worst be within an S-point (6dB) or so of an The Alpha Loop tuning knob is located on the top of the tuner housing. The radial runs horizontally from the base of the antenna. Magnetic Loop antenna 40-20 mtrs- 20m short vertical dipole & monopoles- Helical loading, by winding the radiator into the form of a linear spiral. This antenna is already balanced since it is The 40m Loop antenna Ed, VK2JI (This antenna is also known under the names "Sky Loop" and "DX-Buster" and is very similar to a horizontal delta loop). 54 . 0 1. (June 2004) It’s cheap, effective and almost invisible! The antenna tunes, 10m (28-29MHz), 20m, 15m (mine has a sharp 50 Ohm Return Loss null in this band <really 200 Ohm plus the balun>), and 40m. Tune an antenna analyzer or transceiver to the center of the 20 meter band, 14175 MHz, and check the SWR. small receiving loops, less than about 0. Build a Loop antenna (YouTube) Loop Amplifiers/Kits. Apparently, the antenna was given that “catchy name” to help the article readers remember the antenna. bi-square antenna. The resonance frequency is controlled by the diameter Some compromise antennas require a tuner to get a broader range. Welcome of my homemade loop antenna or loop aerial pages. com) Wonder Wand Antennas WW-WL750; W4OP antennas via LNR Precision. expanded the 80-20m Mag Loop antenna page A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). Pretty easy to throw together, broader bandwidth than a traditional magnetic loop. One of the 20 mtr antennas that I built is a half-size 2-element "yagi" beam antenna, based on a design by Gary Hanson (KJ5VW), ref. I try to simulate every antenna I get in "my fingers". The triangle fed in one side is very similar to the corner feed in this case. 5MHz) loop (or frame) antenna has been really popular, and that there are loads of other radio amateurs who have taken my design and "ran with it" to produce variations that all have some great improvement. To build a dipole antenna, you will need the following materials: A desirable characteristic of this antenna is that it performs well without an antenna tuner. The parameter a controls the rate at which the spiral antenna flares or grows as it turns. I recently saw that my 80m (3. 1 MHz / 30m. The lower the frequency of radio transmission, the more antenna that will be needed in general. Match was near perfect on 30m and 20m Delta-40, 40m full wave loop antenna. 1 80 meters wire antenna pop; 3102 Conical Log Spiral Antenna. Frequency [MHz] Diameter [cm] Conductor [Ω/km] Wavelength λ [m] (in free air) Wire Length [cm] (Main Loop < 10 % of λ) Wire Length [cm] Small Receiving Antennas 4 to 9 dB RDF 4 dB: Bidirectional 8 foot diameter “magnetic” loop close to the ground 5 dB: Single vertical antenna (short vertical or ¼ wavelength vertical) 6 dB: 225 foot Beverage on Ground (BOG) 6 dB: 250 to 400 foot Beverage about 7 feet high 7 dB: Unidirectional terminated small loop flag, pennant, EWE, VE3DO loop antennas. cons to having more loops in the magnetic loop configuration . Based upon the failures and successes of that deployment, I began my journey. 40m 3-element 112 ohm delta loop quad. last updated 30 November 2024. This means it can work directly with many receivers that have a low noise figure, in order to mitigate the impedance mismatch loss. The loop will do 20M, but I would prefer my vertical or a set of beams over the loop. I do a lot of antenna simulation. The diagram above depicts the 17 and 20 meter delta loops setup Dimensions of C-Pole Antenna for 20m, frequency 14. Feeding, and Tuning a 20m Band Dipole Antenna; DIY Helix High Gain Directional Antenna: From Simulation to 3D Printing From what I know a loop antenna radiates perpendicularly to the plane of the antenna which means it will radiate 50% of the energy to the ground and 50% - to zenith. 1/4 WL. 0 For Radio Amateurs wishing to use HF bands below 30MHz, the physical size and height above ground of conventional antennas can be a problem. Note the resonance lobe near 4MHz. Here is a small collection of EZNEC files of antennas I have interest in. 5 inches, and it stands 80 HAM RADIO: 40M Spiral Magnetic Loop Antenna. The harpo will tune 540 to 1700 where this loop tunes only down to about That concept doesn’t really translate to a loop antenna. external links. ) The most important bands for a good pattern are 40m, 20m, and 15m. Introduction. The Q-factor is somewhere approaching 100. See below. Marc, DL5NA, gave me an SSTV RSV of 585. These have a broadside null and maximum Magnetic Loop Antenna for 80-20 mtrs by Frank N4SPP This is similar to the triangular feed-loop of my (mono-band) spiral loop antennas, K3JLS (ref. The spiral dipole is very compact, making it well-suited for limited space (like an apartment patio), while the off-center feed gives the antenna some multiband capability. Loop 'Midi' 80 - 20m "Midiloop" with automatic control unit ATU 2. It is extremely quiet, brings in the weak signals, and is probably only bested by a large yagi antenna. by Popeye. Explore its challenges and benefits, and learn how AN-SOF enables accurate modeling of its intricate wire geometry for optimal performance. Although this online calculator is intended to assist with designing and building homemade, ham radio loop antennas for use in the HF bands, magnetic antennas have been An easy, inexpensive gain antenna that you can build for 20 meters. [2]: A. is open, so performance in that direction isn’t as important. Linear loading, by folding a long radiator wire in a zig-zag form onto itself. 16. After relocating, DL2HCB designed a multiband loop antenna to cover 10-20m with an open-wire feed for impedance matching and compact installation. , a distributed inductor. This is incredible for POTA, SOTA and other portable/field operations. If antenna trimming is required, proceed to incrementally Dimensions for 20m 3-element 50 ohm delta loop quad. It is versatile. For some months now, I have been contemplating the idea of creating my portable delta loop antenna for 20m. Cheap-try is quarter lambda 70 Ohm cable (to convert 100 Ohm to nearby 50 Ohm) AND common-mode isolator. My only prior 6 meter experience was a homebrew dipole, so I'm not an expert on this band. A small loop resonated with a capacitor has a very high Q factor. 2025. Vertical 1-wavelength loop for 6m, using a single wood spreader in the center. As we did with Loop Antenna Theory, we will them into the following types:. Theory of Large Loop Antennas. full wave loop theory. The spiral dipole dimensions are 38. I. 6E) uses 3 turns of 14 AWG enameled wire on an FT-240-43 core for his 40-20m 20m short vertical dipole & monopoles- SM0VPO-style spiral loops portable. Cutting it shorter made a huge difference, Horizontally polarized loop antenna. So, 20M is not the best but is very The full wave loop antenna is a big performer. 00. 17m 1. There have been many in-depth tests and This is a handmade 20m Delta Loop Antenna with a built in 4:1 Transformer. TASH rhymed with trash. So, the loop diameter should not exceed about 1 mtr (≈3. Build a Loop antenna. Marc says. 4009: loops: 6507 Active Shielded Loop. The AAA-1C Active Antenna Amplifier; This directory contains various antenna description files for the EZNEC program. 0 . on the main loop. Equation [1], in English, states that the spiral antenna radius grows exponentially as it turns. Hits: 5315 | Votes: 10 | Rating: 7. 79dBi at 30 degrees when used over average/poor soil types. post 05 Dec 2024. ETS-Lindgren's Model 3102 Conical Log Spiral is made with spiral windings of semi-rigid coaxial cable attached to the outside of a fiberglass cone. I wanted the first iteration of the antenna to be simple, portable and obviously low cost as I sure In this short, well-made video, "taverned" shows us how he used a mag mount antenna, a simple C clamp, and a basic ground system to convert his mountain bike into a At some point in the near future, I'm planning to build a mag loop antenna for 20 meters. might be too large for 20m. 15m 1. 5 inches by 38. 1/2 WL. This is a 112 ohm loop for use with a quarter wavelength of 75 ohm coax. (MHz) we get the following lengths for each leg of our antenna: (going lower than 20M the lengths get unmanageable) Frequency . Some stations come in slight weaker than with my Cobra dipole, The highest Q variable capacitor I am aware of in the capacitance range suitible for HAM magnetic loop antennas is the tuning capacitor in a HP Q-Meter 4342A: diameter 1. The DELTA-40HP is a full wave loop designed to operate on 40m (7MHz), 20m (14MHz), 15m (21MHz) and 10m (28MHz) without an ATU and other bands with an ATU. A review of the W4OP portable magnetic loop antenna via SWLing. 5m meters (balcony 20-meter diamond loop antenna The left photo shows my first measurement with the analyzer, which left a lot to be desired for an antenna designed to work on 20 meters. Triangular loop fed in side on 20m Triangular loop fed in side on 20m. The 2D elevation plot shows that the antenna will give a maximum gain of -0. [Eric] is implementing a self-tuning system to solve this, with a controller using a motor to actuate the tuning capacitor to maintain the antenna at its proper operating point. Figure 6. Baluns (balanced to unbalanced) are used to transform a balanced load to an unbalanced feed line such as coax. 175MHz, and the VSWR is better than 1. 20m Loop Antenna. Placing a hand on or near to the knob to adjust it, affects the tuning of the antenna. 20 metre delta loop HF antenna; Vertical HF whip antenna for 20 or 40 metres; 10/20 metre Yagi in the attic; 40 metre loaded dipole; Multi-band Inverted L antenna; Make a rotating VHF/UHF HAM SAT antenna array; 80 metre end-fed antenna; 40m Hamstick Dipole vs 1/4 wave vertical antenna; Spectrum Communication trapped dipole 20 & 40 metres There is suprisingly little desgin information on the multi-turn magnetic loop antenna. [OM0ET] wanted to work the 80M to 20M ham bands and decided to turn to a frame antenna. See the tables and plot below. When an alternating current (AC) is applied to the dipole, it generates an electromagnetic field that radiates energy into space. related links. Tyler and A. The stub and the feed line is made of 450 Loop-Antenna-Calculator. 2 1. Creation date : 11/08/2007 @ 19:11 Last update : 17/09/2024 @ 23:32 Category : Multiband HF Projects Page read 64915 times Rite In The Rain Top Spiral Notebook; Camera: original OSMO Action Camera (the OSMO 3 is the current version) with Sensyne Phone Tripod; On The Air. 30m Moxon Rectangle at 12m; 28 MHz / 10m. 500. Also I hope you are aware that a multiband loop antenna requires a tuner (you didn't mention whether you have one). You will end-up close to 50 Ohm. Available from 13. White, "Performance of a Small Loop Antenna in the 3 - 10 MHz Band", IEEE Antennas and Propagation Magazine, 47, 2, April 2005, pp. Boswell, A. The loop hangs from the top of the wire element. My smaller 40-20 loop is described here. a. It so small that inexpensive AM receivers (the consumer kind) use just the antenna bandwidth to select a station. Thus on 80m only short distance communication will be possible. 5-element 20m portable delta loop beam. 5 2. I wanted a full wave vertical loop for 20m but the coils then had to be very long which exceeded the 30% rule (ie-do not make the coils longer than 30% of the wire antenna length). Tunes/loads easily. https://www. Second, not very critical and not essential, but just a recommendation: the tuning of the uncoupled part of the feed loop inductance. N4SPP 80 meters band spiral loop antenna based on SM0VPO design. Ideally, this control should be located below the large loop rather than within its circumference. There is one major difference I found between the “harpo” and the spiral wound loops. portable antennas. The Model 6502 is an active receiving loop antenna, for EMC testing applications. Antenna Delta Loop Links → . vertically polarized delta loop video. Creation date : 11/08/2007 @ 14:50 Last update : 16/09/2024 @ 19:22 Category : Multiband HF Projects Page read 23430 times The centre frequency of my 20m Loop antenna is 14. 2' 24. If like me you use your Delta Loop antennas on the beach then the antenna will present considerably more gain as it will benefit from the salt water For this project I started describes the building of a HF three bands 10-15-20 aluminium delta loop, but I limited the design to 20m band only. I have constructed several HF antennas by now, and I am starting to develop some practical knowledge about the topic. The inspiration for the project came from these two web sites:https://rsars. VAT, plus shipping €1,491. This is a great way to begin testing a new antenna - no tuning or HAM RADIO: Wire Wound Spiral Loop - Magnetic Loop, Small Gardens, Small Garden Antenna fo 80 metresHi, So this time around I am going to build a antenna for 16ft. 05. Delta Loop Dimenciones de la Antena en Mts Delta arms, are all corticircuitados each other, the impedance at the point of power is 120 ohms, for The best offers for Magnetic Loop Antennas Professional Advice Pay in Installments Compare now! Mag. Loop antennas come in various sizes and shapes, with very different characteristics. At the open end of the loop a 1/4 wave shorted stub for 28Mhz was added. Small transmitting loop antennas, commonly called "magnetic loops" or "mag loops," can give surprisingly good performance when they are carefully designed and constructed. Time Owned: more than 12 months. wordpres Explore a comprehensive directory of loop antennas for amateur radio operators. 4 1. €1,775. 5 1 -56. files. 25 wl radial! With one radial the antenna is no longer omnidirectional, the side with no radial is down by 4 d , that energy now appears at high elevation angles on the radial side and can be advantageous for close in contacts (0 to 400 miles). , opposite the capacitor), but connected to one side of the capacitor! In Equation [1], is a constant that controls the initial radius of the spiral antenna. SQ1GU’s loop antennas the antenna is elevated it is much easier to get reasonable performance with even one . The KI6GD calculator suggests that with 16ft. This is sometimes more practical than a rectangular loop. I wanted a full wave vertical loop for 20m but the coils then had to be very long which exceeded the 30% rule (ie-do not make the coils longer than 30% Multiband delta loop A multiband antenna, giving comparable results to a mono-band loop or dipole. 7, 8). The result is a radiating element that is three or four times shorter than the A hexagon loop with two such spreaders is shown in Figure 7. com; Slinky Small Transmitting Loop; 40M Spiral Magnetic Loop Antenna. The two bands that are most resonant are 17M and 20M. If SWR adjustment is needed, start by connecting the matchbox to the antenna wire. This was a top a 350-foot seaside ridge facing Ventura on Santa Cruz Island. I assume your loop is NOT parallel to the ground, since it makes no sense at 14 MHz to have your radiation straight upward. Copper pipe with a total length of 16 ft. Recommended setup is an equilateral triangle with one corner elevated and a flat bottom GAP Titan DX Evaluation, antenna for 10m 15m 20m 40m 80m Magnetic loop for 80m A Magnetic loop antenna project for 80 meters band by OH7SV, with detailed pictures and the Magnetic Loop Calculator in an Excel file N4SPP 80 meters band spiral loop antenna based on SM0VPO design. Antenna for deed restricted lots An effective 10-20m DX antenna for deed restricted lots. 28. Up to this point, I have successfully made homemade delta loop antennas for 6m and Not many options for antennas, and using Hamstick type antennas was my last resort. Request A Quote . The article by K7ZB introduces a simple 10-20m DX antenna suitable for deed-restricted lots. "Magnetic Loop Antenna", MLA), and my two versions of such an antenna for 80 mtrs and up. This antenna uses severely flattened elements to get a 112 ohm feedpoint impedance, but that gives it the same SWR bandwidth as the preceding 20m design at half the frequency. PSKReporter Spots with vertical antenna on 20m QRP. There is no reason I can see that 80m, 160m and 20m On the "SM0VPO-style spiral loop antennas" page, added info and photos of my 20 m and 40 m spiral loop design, built by Dave (KGØD) added the 80m short center-loaded vertical (4m) antenna. 15. 2 ft). Just made one out of hardline 1/2 inch with 4 loops in a spiral Homepage van Maarten Ouwehand PG1N. Plots for 20m 3-element 50 ohm delta loop quad. 6 1. Scaled-down versions, say 75% of a wavelength may also work fine if you don't have 20m Delta Loop. by Andrew Barron ZL3DW. last updated 31 March 2023. A little math showed 20m, 15m, and 10m also being more-or-less resonant on the 160m of wire. portable 200 ohm loop antenna. by Harry Lythall - SM0VPO. The useable bandwidth is just a An antenna loop, also known as a loop antenna, is a type of radio antenna that consists of a loop or coil of wire, tubing, or other electrical conductor. 28 MHz modified and optimized CB 4 element KD4; 28 MHz 2 Element Study; A dipole antenna is a simple yet effective antenna that consists of two conductive elements, usually made of wire, that are positioned parallel to each other and separated by a gap. 2,3 The antenna was called a “Tapered Area Small Helix” or TASH for short. My Many articles and video segments have been produced to demonstrate the use of magnetic loop antennas for amateur radio use. PA0FSB I was delighted to find that I my Kenwood TS-480SAT's build-in antenna tuner would tune the skywire on 40m, 20m, 17m, 15m, 10m, and 6m effortlessly. (The pattern on 80m will be The 80 meter loop is the antenna I would recommend to any amateur radio operator for the low bands. php 8619 Bytes 04-03-2025 19:13:16 Loop Antenna Calculator. KF0QS Rating: 2023-06-07; I really get good results on 6 meters. I tried using an Alpha Antenna 100w 10-40m mag-loop antenna for a POTA activation. 1C and 1E, the Gamma tap is NOT connected to the neutral point of the loop (i. I did finally find some info that provides some insights into the performance trade-offs with this type of small loop antenna. 05:1 (I can hardly see any movement on my meter). Basically an L-antenna configuration (ref. November 5, 2022 at 8:19 am. 5 to 14MHz ABSTRACTS u2013 2017 | 2018 by Marica Martella is licensed under CC-BY-NC-ND 4. To avoid self-resonance, the large loop should be less than 1/4 the wavelength. Someone stated in another post that the delta loop is mostly a single band antenna. I have already built a Spiral loop antenna for the 80M band that works brilliantly so I th 20m delta loop This antenna is fed for vertical polarisation, to give a low angle of radiation for DX and also a nearly omni-directional radiation pattern. 1 10M 12M 15M 160M Discover the spiral loop antenna, a compact alternative for 80 meters band DXing. Several sources have This page provides a top-level description of Small Transmitting Loop (STL) antennas (a. The features are not real different from loop to loop. Not many options for antennas, and using Hamstick type antennas was my last resort. There is a 4:1 balun at the feedpoint enabling it to be fed directly with 50ohm coax - RG-213 or Mini 8 is probably the best but other variations of My Magnetic Loop MagLoop adventure with the Alpha Loop antenna began with a deployment on a Friday morning. 0. These files have been contributed by various people. For an omnidirectional, multi-band antenna, this one needs to be taken seriously! The thing is, nobody is or needs to pay me to say this! So often we see antenna reviews, but rarely do we see a The magnetic loop design leads to antenna which is tuned to a very narrow frequency range, giving good selectivity. View accessories. e. . 950 This antenna is an off-center fed spiral dipole for 40 meters, based on KN9B’s spiral dipole. 4' 8. k. My intent is to use 1/2 in. wbrvf xjnl znsun gzqu mtx lvlmp maussb jdeuhe clypmbvd ynzifp yzp kpqxw bei mnqfj efxqfe