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Query: Quad
Links: 186 | Categories: 9
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January 1955 QST article by W5DQV about constructing a Cubical Quad antenna for 14MHz PDF File -
Backpacking, boating or mountaintopping ? Invest your time and pack this novel directional gain antenna on your next expedition -
Theory of horizontal loop antennas, as discovered by G2PL using a lowered quad antenna and theorized by ZS6AKA -
Let's explore the cubical quad antenna, or quad, and see what it really is and how it really works by w8ji -
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The Quadlong antenna for the six meter band. This antenna feature a total gain of 6,4 dBd, F/B 21 dB and is also available in 70MHz version. Includes detailed pictures and plot diagrams. -
A javascript online calculator for popular wire antennas, from the standard easy to build flat-top dipole, to the inverted V dipole, but also the Quad Loop, and the equilateral delta loop antenna -
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A 5 band two element quad antenna working from 20 to 10 meters using hardware-store parts or modifying an existing commercial triband quad by KC6T -
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A 27-28 Mhz quad loop antenna by Bernard Mourot F6BCU in french -
probably the most simple and inexpensive antenna you could make for 23cm. -
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Durable Easy To Build 4 Element 6 Meter Quad Or 6N2 Or 4 Element 6 And 5 Element 2 Permanent Or Portable you decide based on your needs By WA8UEG -
A two meter Quad antenna project with detailed instructions on how to adjust the Quad gamma match -
A 2 element small footprint 40 meter phased, reversible, downsized quad array antenna. -
The information in this article has come from many amateur sources, the most notable was from WA6TEY (sk 1985) Ray Frost, who was a pioneer of VHF Quad designs and one of the best Southern California Transmitter Hunters. Ray built hundreds two meter quads in single and paired configurations as well as his famous mobile radio direction finding quad. -
Amateur Radio HF Cubical Quad and Delta Loop antennas manufacturer based in Spain -
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An online javascript calculator for cubical quad antennas, simply input the resonating frequency to calculcate up to a five element quad antenna. This quad antenna calculator let you determine the total length of each element and spacing among elements. -
Calculating the length of a resonant square quad loop -
based on an FT-1000MP Reflector discussion with Bill Heinzinger, W9OL, 15/16 November 2002 -
Constructing a compact, single-feed triband Moxon antenna for 20, 15, and 10 meters is detailed by DU1RZ, drawing from his personal experience with space-constrained antenna projects. Initially fascinated by cubical quads, the author transitioned to Moxon designs in 2005 after realizing his roof space was insufficient for a bulky quad. His first experimental monoband Moxon for 15 meters, built from repurposed materials, provided solid DX QSOs for seven years, despite being slightly below the 21 MHz band center. The project outlines the design process, including using the _MOXGEN Calculator_ for element dimensions and material selection, such as #14 AWG enamel copper wire and fishing poles for spreaders. DU1RZ shares insights from simulations with DL2GMS regarding insulated versus non-insulated wire performance, noting that insulated wire can shift resonant frequencies lower. The assembly instructions cover preparing wire elements, connecting feed points, and tuning the antenna, with initial SWR measurements taken at 10 feet and final readings on a mast showing excellent results: 1.0:1 on 14.225 MHz, 1.1:1 on 21.250 MHz, and 1.3:1 on 28.50 MHz. Transmission tests with 4F1BYN indicated a front-to-back ratio of approximately 2 S units with 10 watts output. The author emphasizes adaptability, encouraging builders to use readily available materials rather than strictly replicating his setup. Key observations from DU1RZ and DL2GMS highlight the antenna's strong performance across 20, 15, and 10 meters, good front-to-back ratio, full bandwidth on 20 and 15 meters, and its small turning radius of about 4.18 meters (13.54 feet), making it suitable for limited antenna space. Its lightweight construction and low wind load are also noted as significant advantages. -
A four elements quad antenna for 144 MHz made with PVC pipes -
A page dedicated to the Quadrifilar Helical Antennas, with projects, pictures and antenna plans by OH2GVB -
Perfect Quad Co,Ltd japanese ham radio quad antenna manufacturer -
Article by G4AON about a 4 and 2 Element Quad Antennas for the 6m band -
How to build a QFH (Quadrifilar Helix Antenna) to download images from weather satellites. A complete tutorial on assembling QFH antenna at home with simple and common tools -
This graphics-intensive program designs and analyzes active quadrature ("90-degree") networks for use in SSB transmitters and receivers. -
Quad antenna homebrewing, mechanical considerations by IZ7ATH -
What makes a good solid-state amp ? by Adam Farson, VA7OJ/AB4OJ, May 2002 -
A portable swiss quad antenna project made with components and parts that can be dismounted, in German -
Simple 6 Metre DX Antenna based on an article by LB Cebick in QST May 2002 on a Quad Turnstile antenna. This antenna is basically two full wave loops mounted at right angles fed 90 degrees out of phase to produce an omni-directional horizontally polarized pattern -
Yaesu vx-8r prototype quad-bander on display at the 2008 dayton hamvention. Youtube video -
Learn quadrature modulation through interactive flash programs. These programs will allow you to learn about quadrature modulation and quadrature demodulation without getting overwhelmed by math. -
The 60-page PDF document, "Antenna Systems and Theory For The Non-Technical Ham" by Jim Abercrombie, N4JA, provides a foundational understanding of antenna systems. It explains basic antenna theory, including how antennas work, electromagnetic wave polarization, and the role of frequency. The resource details various antenna types such as flat top dipoles, inverted-V dipoles, shortened loaded dipoles, G5RV dipoles, Carolina Windoms, and end-fed configurations. Vertical antennas, including ground-mounted trapped verticals and inverted-L verticals, are also covered. Directional beam antennas like monoband Yagis, cubical quads, and log-periodic arrays are discussed. Propagation modes, including ground-wave, direct wave, and skywave propagation, are explained in detail, with specific attention to the D, E, and F layers of the ionosphere and their effects on HF communication. Technical concepts such as standing wave ratio, decibels, resistance, and reactance are defined, along with calculations for half-wave resonant dipole lengths. The document addresses feed-line radiation, balun applications, and critical antenna and tower safety considerations. It aims to dispel common antenna myths and educate hams on making informed antenna choices. -
This resource details the construction of a Moxon rectangle antenna, a two-element wire beam, drawing inspiration from a _QST_ article by Allen Baker, KG4JJH, and a project group led by KD6WD. It outlines the use of _AC6LA_ software for critical measurements (A-E) to design the antenna for specific bands like 17 meters, emphasizing the simplicity of adjusting frequency and wire size. The guide covers material selection for spreaders, such as telescoping fiberglass fishing poles, and various hub constructions, including aluminum tubing and PVC joints, with accompanying images. The author shares practical insights from building multiple Moxons for 10, 15, 17, and 20 meters, noting consistent 1:1 SWR at design frequencies and broadbanded performance. It describes the feedpoint assembly using a 1:1 Yagi current balun and wire nuts for robust, adjustable connections. The resource also discusses element insulators made from Lucite strips and attachment methods to spreaders using plastic wire ties and duct tape, ensuring precise element spacing. Performance observations include significant signal improvements (4-5 S units) over quad loops and a unique "DX-Vane" effect where the suspended antenna self-aligns with the strongest DX signal. The author also recounts an unsuccessful attempt at a dual-band 17/20 meter Moxon, concluding that the Moxon is inherently a monoband antenna, supported by _EZNEC_ plots for a 17-meter design. -
Accessing this interface provides entry to one of the largest databases for amateur radio voice repeaters, encompassing over 8000 entries from more than 60 countries. The resource supports both desktop and mobile access, with a default display based on browser type, or forced via a "force" parameter (e.g., relais.dl3el.de?force=mobile). Users input a QTH-locator to find local repeater information. The database integrates FM-Funknetz servers and hotspots, potentially creating duplicate entries but ensuring new FM-Funknetz repeaters are immediately displayed. DMR repeater information, including status and talkgroup configurations, is sourced directly from DMR+ / ircDDB and Brandmeister systems, with real-time updates for active and default talkgroups. C4FM/Wires-X installations, particularly MMDVM-based gateways not listed in Yaesu's database, are identified through Brandmeister dashboard descriptions, marked with "W-x" or "W-x#MMDVM" for manual entries. D-Star repeater data from ircddb or QuadNet2 is also incorporated, with entries marked (i), (o), or (d) for manual additions. An APRS interface allows searching by callsign, using Sassan, DL3NCK's database, and offers a mobile-friendly, auto-refreshing display that follows an APRS station. Output data can be generated in GPX format for offline smartphone maps or CSV for spreadsheet applications. The database also attempts to determine valid repeater offsets based on IARU region and frequency, indicated by a "." after the frequency. -
Pictures and detailed instructions on installation of the LightningBolt Quad antenna -
Explains the fundamental principles of Software Defined Radio (SDR) and Digital Signal Processing (DSP) within the amateur radio context, serving as an initial entry point for hams interested in these technologies. It covers the architectural shift from traditional analog hardware to software-centric radio systems, detailing how digital signal processing algorithms are applied to modulate, demodulate, and filter radio signals. The resource compiles a list of external links to _white papers_ and project pages, offering further technical depth. This page provides a foundational understanding of SDR/DSP, enabling operators to grasp concepts like direct sampling and quadrature mixing. It references various projects and discussions, allowing users to explore practical implementations and theoretical underpinnings. The curated links direct users to resources that might cover specific SDR hardware platforms or software applications, facilitating deeper research into the subject. -
Commsaudit uk, i/q quadrature , hf receivers, rf, multicoupler, multicouplers, switch matrix, antenna matrices, masthead amplifier,, vhf receiver, uhf, -
Cheap but effective multiband quad antenna covering the entire horizon on 10-12-15-17-20m bands. -
Nuand id the maker of bladeRF - the USB 3.0 Superspeed Software Defined Radio, 300MHz - 3.8GHz RF frequency range Independent RX/TX 12-bit 40MSPS quadrature sampling -
It has been 40 years since the VHF-UHF Quagi antenna--a combination of the desirable features of a Yagi and a cubical quad--was developed and the design was first published in the newsletter of the Southern California VHF Club, a forerunner of today's Western States Weak Signal Society. -
Amateur radio Quad Antennas manufacturer based in Italy produce HF and VHF Quad antennas, and spare parts. -
A quad turnstile consists of two cubical quad loops oriented in a diamond configuration and angled 90 degrees apart from one another with both diamonds sharing the same top and bottom points -
Rotatable Antenna with Phased Elements based on the orignal design concept of HB9CV antennas, is considered to have an higher gain than standard quad antennas. The Swiss Quad Antenna does not need any spreader or boom. -
An inverted V Dipole antenna for HF bands, working on 10 20 40 and 80 meters band. PDF Presentation -
A light and sturdy Quad for 10 and 15 meters. Basic Quad antenna design considerations. Building and assembling a dual band HF QUAD antenna, designing and joining cross-arms and boom, assembling spreader and element wire installation notes. QST article.