multi band antenna

299 links - and 2 categories

Pages: [prev] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Antennas : 20M : 20 meter Vertical Antennas

4m Tall Vertical Dipole for 20m - Constructed in May 2008, this innovative 4m tall electrically full-size halfwave vertical dipole, tunable to multiple bands, offers HF coverage despite its space-saving design. Inspired by cost-effective DIY alternatives, the antenna design departs from conventional center-fed approaches, utilizing asymmetrical dimensions. Despite resonance challenges, the antenna's performance remains viable, boasting broad bandwidth and adaptability, as demonstrated through SWR measurements and EZNEC predictions.
[ Hits: 93 | Votes: 0 | Rating: 0 ]

Antennas : 40M

Spiral Dipole Antenna for 40m - This antenna is an off-center fed spiral dipole for 40 meters. 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.
[ Hits: 295 | Votes: 3 | Rating: 7 ]

Antennas : Antenna Calculators

Online LInked Dipole Designer - The page for designing linked dipole antennas allows users to swiftly create a versatile multi-band antenna suitable for portable applications in outdoor settings, such as in the field or on mountain tops.
[ Hits: 99 | Votes: 0 | Rating: 0 ]

Antennas : End-Fed

Multiband portable wire antennas - Vertical end fed antenna used for portable operations. The antenna will work on 80 with acceptable results, it will work fine on 40m, and it will be a good deal better than a normal 1/4 wave GP on 20, 17, 15 meters.
[ Hits: 187 | Votes: 0 | Rating: 0 ]
Multi-Band End-Fed Antenna Design for Limited Space ^new - This document details the construction of a multi-band end-fed antenna, suitable for situations with limited space for larger antennas. The design utilizes a 1:49 to 1:60 impedance transformer to match a half-wave wire antenna fed at one end. Compared to a traditional dipole, this antenna resembles a highly unbalanced Windom antenna with one very long leg and a virtual short leg. The design eliminates the need for radials but relies on the coax cable shield for grounding. The document recommends using at least 10 meters of coax and installing a common mode filter at the entry point to the shack for improved performance.
[ Hits: 76 | Votes: 0 | Rating: 0 ]

Antennas : End-Fed : End Fed Half Wave Antenna

Full size 80m End Fed Half Wave Antenna - The author reflects on expanding their antenna for 80m coverage during lockdown. They extend the End Fed Half Wave (EFHW) using a Spiderbeam pole and "cheating" by dog-legging across their garden. Despite challenges, they achieve coverage for multiple bands with minimal cost. Practical Wireless features EFHW antennas, including a pre-made 20m EFHW extended for 40m.
[ Hits: 94 | Votes: 0 | Rating: 0 ]

Antennas : Fan Dipole

VE6LK Fan Dipole - Multiband dipole antenna working on 80-40-20-15m, a 3 element antenna, 15m being a 3rd harmonic of 40.
[ Hits: 163 | Votes: 1 | Rating: 10 ]

Antennas : HexBeam

Homebrew HexBeam Antenna - The Hex Beam page by W1GQL page, a document dedicated to home brewing hex beam antenna with dimensions, info on spreaders, wires to use, spacing tips, feed line information, mast to use, multi-band version and antenna height
[ Hits: 108 | Votes: 0 | Rating: 0 ]

Antennas : Mobile

DIY Portable Car Whip Antenna - Being frequently away from home, the author owner of an Elecraft KX3 missed the opportunity to work /M. They devised a portable antenna solution, incorporating a coil and car body, enabling multi-band tuning. Despite its unconventional design, the antenna exhibits promising performance, resembling a vertical dipole.
[ Hits: 54 | Votes: 0 | Rating: 0 ]

Antennas : Moxon

Home made multiband MOXON - Multi band Moxon Yagi Antenna for 10,15,20 meters band with just one feed line. Drawing and project with dimensions
[ Hits: 488 | Votes: 0 | Rating: 0 ]
Moxon Mania - Building the Ultimate 4-Band Moxon Antenna - The article details the design and construction of a four-band Moxon beam by a radio amateur. The beam, mounted atop a rooftop tower, aimed for gain over a dipole on 20 meters, cost under $500, and included additional bands. The design features fiberglass spreaders, four bands (20/15/10/6 meters), and a single feedpoint. The construction involved computer modeling, NEC source code, and specific dimensions. The article outlines the assembly, materials, and tuning process, including in-situ adjustments for optimal performance. Despite initial challenges, the beam improved signal strength and facilitated contacts on multiple bands, marking it as the best HF antenna the author has owned.
[ Hits: 96 | Votes: 0 | Rating: 0 ]

Antennas : Multiband

Space-Efficient Excellence: Inverted L Multi-Band HF Antenna - Discovering a solution for limited space, the inverted L HF antenna emerges as a stellar performer. Half the size of a dipole, it ensures optimal installation in restricted areas, maintaining superb transmission (TX) and reception (RX) characteristics. Spectrum Communications' multi-band version, featuring traps, proves even more space-friendly without compromising performance. A fiberglass pole offers sturdy support, while proper grounding, an RF choke, and occasional tuning contribute to a high-performing and reliable antenna system.
[ Hits: 187 | Votes: 0 | Rating: 0 ]

Antennas : Portable

A Compact and Stealthy Field Portable Antenna - In the quest for an ideal field portable antenna, the author recounts experiments involving various wire configurations. While a previous candidate, a 41ft random wire, proved effective but lacked stealth, the search led to a surprising rediscovery of a design previously rejected—the Rybakov Antenna. With a focus on simplicity, rapid deployment, and multiband capability, the author explores the versatility of a 26ft Rybakov, avoiding the halfwave trap. The article delves into the antenna's performance and its potential as a discreet, resonant solution for field operations, addressing the challenges encountered during a POTA activation. Additionally, the Unun/Balun design used in conjunction with the Rybakov Antenna is discussed, providing insights into achieving a balanced system.
[ Hits: 153 | Votes: 1 | Rating: 1 ]
Portable Half-Square Antenna: - The author explores a portable version of the half-square antenna, typically a single-band structure. Using a 9:1 unun for versatility, they describe construction with speaker wire, deployment using collapsible poles, and field tests, achieving successful contacts on multiple bands. The article suggests efficient matching methods and concludes with the antenna's integration into the author's portable options.
[ Hits: 126 | Votes: 0 | Rating: 0 ]
K4SWL Antenna Plus ^new - This project details building a multi-band antenna for park activations. The author constructs a random wire antenna with a 9:1 UnUn for improved performance. Winding the toroid core proved challenging, but the completed antenna shows promising results in initial tests with an analyzer. Further field testing is planned for a future activation.
[ Hits: 52 | Votes: 0 | Rating: 0 ]
Vertical Dipole Array for 20-17-15 Meters ^new - This article explores the evolution of antenna choices for DXpeditions, focusing on the shift from mono-band VDAs to a multi-band solution. It details the design and construction of a lightweight, versatile 20-17-15m VDA, utilizing readily available materials like fishing rods and IKEA breadboards. The author discusses challenges, adjustments, and offers guidance for replication.
[ Hits: 67 | Votes: 0 | Rating: 0 ]

Antennas : Stealth

The Infamous Attic Dipole - An attic wire antenna with several modifications during the time. Began as a simple coax fed doublet antenna, and upgraded to a multi-band hf fan dipole, till the G5RV all deployed in an attic.
[ Hits: 102 | Votes: 0 | Rating: 0 ]

Antennas : Theory

Variations on a Dipole - Antenna patterns are all about interference. Presentation on wire antennas for HF bands. Dipoles, horizontal and vertical dipoles, effects of ground on radiation patterns, multi-band wires antennas. Knowing what you should expect from the radiation patterns for waves on your wires will help you choose what will work best for your needs. The principles of interference can lend insight into what to expect from a wire antenna.
[ Hits: 98 | Votes: 0 | Rating: 0 ]

Antennas : Vertical

Modified Ground Plane Antenna Adds Second Band - This article explains the trick of how to shorten and lengthen pairs of radials to make a 2-band ground plane antenna. Included is a "Table of Multi-Band Possibilities" covering the range of 6 to 40 meters.
[ Hits: 53 | Votes: 0 | Rating: 0 ]