20 meter spiral loop antenna This antenna is an off-center fed spiral dipole for 40 meters, based on KN9B’s spiral dipole. nonstopsystems. com Pretty easy to throw together, broader bandwidth than a traditional magnetic loop. The tuned loop is spiral-wound and square, has about ¼ λ total wire length. Or fetish in my case. Build a Loop antenna. 20 MTR VERTICAL MID-LOADED 2x3 MTR (2x10 FT) DIPOLE. Mar 9, 2022 · Discover the spiral loop antenna, a compact alternative for 80 meters band DXing. Let's build a loop for 20 meters that exhibits around 65% efficiency. The project is straight forward, simple, and gives you emergency communications while you peddle down the road. Explore its challenges and benefits, and learn how AN-SOF enables accurate modeling of its intricate wire geometry for optimal performance. See ref. A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). Searching for a half-size half-size 2-element Yagi, I found the design by Gary Hanson (KJ5VW), ref. 160 meter full wave loop antenna The antenna is a 10 - 160 meter horizontal loop fed with 450 ohm ladder line all the way into the ham shack to an Palstar AT1500BAL balanced line antenna tuner Super Loop Antenna Superloop III designed by Jim, W4FTU AM Antennas The ultimate AM loop antenna article. 20 Meter Circular Magnetic Loop by IW6DFW. It is basically a transformer loop antenna: it consists of a multi-turn tuned loop and a small feed loop. It turns out that we can use the two twisted wires at the end of the diamond spiral as a tuning stub. 5 and 6 for similar designs. I have already built a Spiral loop antenna for the 80M band that works brilliantly so I th Aug 5, 2016 · A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). Introduction. Sep 4, 2020 · 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 mobile station. Antenna analyzers only inject a very small amount of power into the antenna system - nowhere near enough to excite effects that normal operating power may, such as saturation in balun or unun transformers, or heating of transformer cores. My really short 20 mtr dipole (2x 0. 3 ft !!!) ) that can easily be installed vertically is described here. 5 inch copper pipe and each side will be 3. Read on and discover the fantasy of loop antennas. 5 dBi. Portable Loop Antenna This loop it is small and light enough to carry while operating, it disassembles into small but rugged pieces that fit easily in a backpack or gym bag, and it can be tuned from 14 MHz to 30 MHz. https://www. Mar 16, 2021 · This antenna is very compact: ≈ 120x120 cm (4x4 ft). Nov 30, 2024 · Figure-8 Bow Tie multiband horizontal loop; 80m Horizontal Loop Antenna for Field Day; Portable 200 ohm loop antenna; Wire quad antennas; 5-element 20m Portable Delta Loop beam; simple 2m 2-element quad; Feeding large loops; Double loops; hand-held DF loop for 40m through 15m; loop antenna photos; BACK TO: antenna designs. As regards your indoor antenna- I am in a very similar situation, and my solution was to construct what I call a “Spiral Dipole” in my attic. Nov 17, 2024 · Small Magnetic Transmitting Loop for 80-20 meters; Slinky Small Transmitting Loop; 40M Spiral Magnetic Loop Antenna. com/radio/ If you like my videos, please subscribe here: 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. In May of 2008, I dug up my my 20 meter mid-loaded short dipole from a dark corner of my "antenna cemetery". The 20 mtr version is compact and light enough that you can use it with a simple TV antenna rotor/rotator. The Optimum Magnetic Loop - W6NBC Mar 28, 2025 · A multiband 80-40-20-15 meters dipole wire antenna that can be extended to cover 160 meters too. The basic concept is this; starting at the center of the attic at floor level, I hung two runs of 2-conductor wire from the roof joists, using wood screw type standoffs designed for 300-ohm twinlead While it may have good VSWR that’s easy to tune up, it may not perform very well. I recorded S-meter signal strength of each Web-SDR for three configurations: 1) antenna mast installed in the umbrella stand, bottom of the loop 60 cm (2 ft) above the terrace floor, 2) antenna installed on my telescopic mast, poking up between the steel I beams of my pergola, bottom of the loop 90 cm (3 ft) above the pergola, and 3) same, but Jul 10, 2007 · I found it quite interesting that when the ratio is 2:1 (loop is twice as high as it is wide), the bottom side of this loop, fed in the center, will yield a feed-point impedance of approximately 50 ohms with a respectable gain of 4. See full list on swling. Jul 24, 2015 · So if my large loop is 5 feet diameter x 1/5 = 1 foot diameter of small loop; Larger main loop for lower frequency. It’s exactly supporting the antenna for 10 meters you offered above. . Build a Loop antenna (YouTube) HAM RADIO: 40M Spiral Magnetic Loop Antenna. 1. This limits the range you can effectively use the antenna at higher frequencies if you’ve optimized it to work at lower frequencies. 4. Finally, on the top in picture shown above, is welded a variable tuning capacitor, a butterfly capacitor (it's important to avoid sliding contacts in the perspective to use an ATU in the future, to avoid sparks due to the high voltage generated). Some of the loops are just one coil, some have tuning capacitors and some have an extra coupling coil. There have been many in-depth tests and simulations These loops are made to enhance radio reception in the broadcast, or medium wave (MW) band range. The loop will do 20M, but I would prefer my vertical or a set of beams over the loop. 5 feet long. To avoid self-resonance, the large loop should be less than 1/4 the wavelength. loop antenna theory Mar 28, 2025 · A 10-20 meters coverage delta loop antenna. I found 20 meters to be very decent. 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. The 80 meter loop really plays well on 17 meters. I recently saw that my 80m (3. 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. Bandwidth, SWR, and impedance of an antenna systems says little or nothing about the antenna's efficiency. It is terminated with a 25 pF variable capacitor. This loop is nice because is it so light and easy to place pretty much anywhere. This time I installed in a vertical position. The "driven element" of such antennas is a dipole. The basic concept is this; starting at the center of the attic at floor level, I hung two runs of 2-conductor wire from the roof joists, using wood screw type standoffs designed for 300-ohm twinlead Mar 28, 2025 · The antenna is basically a full wave 80 meter loop on top and a 40 meter loop on the bottom all supported from a 64 foot center support 80M Vertical antenna with capacitance hat Simple wire antenna cheap to make, using readily available materials, Low angle radiation, with rejection of high angle signals Wide bandwidth, with resonance at the 5 days ago · It will give you just as good as performance with less maintenance problems. The spiral dipole is very compact, making it well-suited for limited 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 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 And if you follow the steps, you should have yourself a nice loop antenna that works well and fits at almost any QTH. We'll make it out of . So, 20M is not the best but is very sufficient. After relocating, DL2HCB designed a multiband loop antenna to cover 10-20m with an open-wire feed for impedance matching and compact installation. I have tried both antennas. Cutting it shorter made a huge difference, 20m Loop Antenna by Harry Lythall - SM0VPO. Now to the other bands. 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. 7 m, 2x2. Check out the ham stick mini-dipole as a better alternative for a space constrained antenna. yegfu gfcpea evhc vegd hmmve cgiu plkigh hmybma bmie hqvwl usbomtw nnmpkg mrgka oyfsu yghvza