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The W5GI Mystery Antenna is a versatile multi-band wire antenna designed for amateur radio operators. It covers frequencies from 80 meters to 6 meters, making it suitable for a wide range of operating conditions. The antenna features a low feed point impedance, allowing for easy matching with most radios, whether or not an antenna tuner is used. Its construction is straightforward, requiring only two vertical supports approximately 130 feet apart, making it ideal for hams without towers. Users have reported excellent performance, particularly on the 20-meter band, where it outperforms similar designs like the G5RV. This antenna is unique in its design, incorporating three half waves in-phase on 20 meters, resulting in a six-lobe radiation pattern. Despite its effective performance, the antenna is challenging to model, which adds to its mystique. The W5GI Mystery Antenna has gained popularity among amateur radio enthusiasts worldwide, with many users praising its ease of construction and effectiveness. Whether you're a beginner or an experienced operator, this antenna offers a fun and rewarding project that can enhance your HF capabilities.

Demonstrates the construction of a **multi-band HF mobile antenna** utilizing a modified CB whip antenna base. The resource details the process of stripping a commercial CB whip, winding a new helical coil with 0.7mm insulated copper wire, and identifying tapping points for various HF bands. It emphasizes the importance of a rugged, slim design for mobile operation, discussing mechanical length, power handling (up to 200 watts), and coil diameter considerations. The article includes a graphic illustrating the antenna's operational principle, where sections of the helical coil are shorted from bottom to top to maintain efficiency and high Q. The resource presents a practical approach to achieving **band switching** without an external tuner, by manually adjusting tapping points on the coil. It provides a table with reference lengths in centimeters from the feedpoint for 7 MHz (40m) through 28.7 MHz (10m), including WARC bands. The author details mounting techniques, suggesting a Diamond bracket for secure attachment to a vehicle trunk, and stresses the critical role of proper grounding for optimal performance. The design allows for operation on 75m and 80m bands by adding a 110mm steel whip.

A modified 20 meter double zepp wire Operating Bands: 40 thru 10 meters (with tuner), basic construction and performance information.

This resource provides a detailed guide on constructing a J-pole antenna specifically for the 2 meter band, which is popular among amateur radio operators. The article outlines the materials needed, including various sizes of aluminum pipes and PVC, as well as the tools required for assembly. It emphasizes the simplicity and effectiveness of the J-pole design, making it an ideal choice for newcomers to amateur radio. The instructions are straightforward, allowing users to build the antenna in less than an hour, and include tips for tuning the antenna for optimal performance. In addition to the construction details, the resource includes practical advice on the assembly process, such as how to cut and join the pipes, as well as how to mount the SO239 connector. The author shares personal experiences and insights on achieving a low standing wave ratio (S.W.R.) and suggests modifications for creating bi-band or tri-band J-pole antennas. This comprehensive guide is enriched with photographs that illustrate the construction steps, making it easier for users to follow along and successfully build their own J-pole antenna.

Cubic quad antennas are renowned for their high gain, excellent front-to-back ratios, and low angles of radiation, making them a popular choice among amateur radio operators. This resource provides detailed designs for constructing cubic quads optimized for 2, 6, 10, 12, and 15 meter bands. The lightweight structure can be easily built using fiberglass tubes and central hubs, allowing for portability and ease of assembly. The article discusses the specific dimensions and configurations required for both HF and VHF applications, emphasizing the importance of proper spreader lengths and boom dimensions. It also highlights the challenges of assembling larger cubic quads in limited spaces, offering practical solutions for hams with smaller backyards. With a focus on multi-band operation, this guide serves as a valuable resource for both novice and experienced operators looking to enhance their antenna systems.

Here is the design of a 2.4 GHz antenna that is ideal for amateur satellite communications. This antenna is easy to assemble because the design itself tolerates inaccuracies in the construction without really affecting performance.

This resource provides comprehensive instructions for constructing a 2 element quad antenna specifically designed for the 10, 12, and 15 meter bands. The antenna features a diamond configuration, which offers improved gain compared to a square configuration. The author shares insights into the materials used, including a square-aluminum boom and bamboo poles, along with construction techniques that ensure durability and optimal performance. This project is ideal for amateur radio enthusiasts looking to create their own antennas at home. In addition to construction details, the author discusses the antenna's performance, noting its effectiveness even at a height of 8 meters. The quad antenna reportedly performs comparably to a 3 element yagi, with excellent SWR readings and strong signal reports from European stations. This project is suitable for beginners and offers a cost-effective solution for those interested in enhancing their amateur radio setup with a homemade antenna.

Homemade 40 through 6 meter HF portable multiband antenna, an aluminium antenna construction article, with plan, drawings and photos

Author evaluated a custom-built passive AM loop antenna, achieving notable DX reception including KLBJ Austin (230 miles) and WWL New Orleans (700 miles). The antenna operates solely on resonant inductive coupling, enhancing weak signal reception without external amplification. This project illustrates how fundamental RF design—calculating inductance, capacitance, and Q factor—can significantly boost performance of consumer-grade radios. Detailed construction techniques, theoretical background, and optimization strategies for effective loop antenna design are presented for amateur and experimental use.

An effective 10-20m DX antenna for deed restricted lots. The article by K7ZB introduces a simple 10-20m DX antenna suitable for deed-restricted lots. The antenna, a 15' vertical design, facilitated contacts with over 200 countries worldwide. Its design employs a telescopic aluminum tube and radial wires for multi-band operation, requiring an external antenna tuner for optimal performance. The mounting scheme and construction details ensure effectiveness and ease of use.

Dissects the internal components of the popular _Antron 99_ vertical antenna, revealing its unique design elements. The analysis details the construction of the coaxial phasing sections, which contribute to its multi-band performance across 10, 12, 15, and 17 meters. Observations include the use of fiberglass tubing for weather protection and the specific arrangement of conductors within the antenna's structure. The examination highlights the antenna's reliance on a series of coaxial stubs to achieve resonance on multiple HF bands without external tuning. This internal architecture provides insights into how the _Antron 99_ manages impedance matching and radiation patterns for effective DX operation. Further details cover the antenna's base mounting and overall physical dimensions.

A multiband 80-40-20-15 meters dipole wire antenna that can be extended to cover 160 meters too.

Details the construction of a **multiband vertical** antenna, specifically designed for stealth operation in a rented property, covering 80m, 60m, 40m, and 30m. The author, N3OX, leverages a 12m Spiderbeam telescoping fiberglass pole as the primary support, noting its sturdiness compared to typical fishing rods while remaining light enough for quick deployment and takedown. The radiating element is a 14 gauge Flex-Weave wire, attached to the pole's top with a rubber grommet, and fed by 27 bare 18 gauge radials spread across a 40-foot square backyard. N3OX describes the impedance matching solution, opting for custom-built L-networks over a remote tuner to enable fast bandswitching. Using an MFJ-259B and EZNEC modeling, base impedances were measured and component values calculated with G4FGQ's L_TUNER and SOLNOID_3 programs. The 80m coil is wound on a 3.5-inch PVC form, while the 30m, 40m, and 60m coils are air-wound, self-supporting #10 wire. Variable capacitors are incorporated for 40m and 30m shunt elements, with the 60m impedance matched by a series inductor. The project includes a **servo-controlled** homebrew band switch, utilizing a two-pole 12-position ceramic wafer switch for remote operation, addressing the limited 80m bandwidth. The entire matching network is housed in a weather-resistant shelter constructed from lumber and aluminum flashing. N3OX reports good DX results at 100W, estimating the total cost between $150 and $250, depending on existing parts.

Theory and construction of a novel trapless center-loaded off-center-fed (cl-ocf) dipole or windom antenna for the 80, 40, 30, 20, 15 and 10m hf amateur radio bands

The 144-430 portable j-pole antenna is designed for amateur radio operators seeking a lightweight and efficient solution for VHF and UHF communications. This antenna is particularly useful for portable operations, allowing hams to set up quickly in various locations while maintaining excellent performance. Constructed from readily available materials, it can be easily homebrewed, making it an ideal project for both beginners and experienced operators alike. The j-pole design offers a simple yet effective configuration that provides a good match across the 144 MHz and 430 MHz bands. Its vertical polarization and omnidirectional radiation pattern make it suitable for local communications and simplex operations. This antenna can be deployed in various environments, whether in the field or at home, and is well-suited for mobile applications. With proper construction techniques, operators can achieve optimal performance, enhancing their ability to make contacts during contests or casual QSOs.

For radio amateurs considering homebrew antenna projects, this resource details several designs from WE6W, an experienced operator. It covers the construction and characteristics of a _160 Meter QRP Loop Antenna_ optimized for high voltage, along with standard and folded variations of the double bazooka antenna. The site also presents a unique Field Day antenna design and instructions for building a Sterba Curtain, a directional array known for its gain. Each design includes practical insights from the author's building experience. The author provides comparative data, such as the performance of a standard bazooka against a traditional dipole, offering real-world context for antenna selection. The Sterba Curtain section includes notes on its beamwidth and gain, crucial parameters for directional operation. These designs are suitable for hams looking to experiment with cost-effective, high-performance antennas for various bands and operating scenarios, from QRP on 160m to directional DXing with a Sterba Curtain, which can offer significant forward gain, often exceeding **10 dB**.

The Pfeiffer Maltese Quad Antenna System presents a unique approach to traditional quad antennas by utilizing a linear loading technique. This method effectively reduces the overall size of the antenna while maintaining its performance capabilities. Designed by Andrew Pfeiffer, the antenna's configuration resembles a Maltese cross, which not only enhances its structural integrity but also allows it to withstand challenging environmental conditions. This system is adaptable, offering various configurations from a 4-spreader Maltese Quad to a 16-spreader Maltese Quadruple-Cross, making it suitable for operators looking to optimize their setup without sacrificing efficiency. This antenna system is particularly versatile, covering multiple bands including 40, 20, 17, 12, and 10 meters. The design focuses on minimizing the physical footprint while ensuring effective signal transmission and reception. Amateur radio operators can benefit from the detailed plans available in the accompanying PDF, which outlines the construction process and specifications. Whether you're a seasoned DXer or a newcomer to the hobby, the Pfeiffer Maltese Quad Antenna System offers a practical solution for enhancing your station's capabilities.

Excellent guide to build your own G5RV antenna by Lombry

The boomless quad antenna is a unique design that offers versatility for amateur radio operators. This antenna consists of two half-wave dipoles arranged in a square or circular shape, allowing for both vertical and horizontal polarization depending on the feed point. The design facilitates easy installation and rotation, making it suitable for various operating conditions. The construction utilizes strong materials, such as bamboo, and incorporates waterproofing techniques to enhance durability. This project outlines the necessary dimensions and materials, including copper wire and insulators, to successfully build the antenna. It emphasizes the importance of tuning each radiator element for optimal performance. The boomless quad is particularly effective across multiple HF bands, including 14 MHz, 21 MHz, and 28 MHz. By following the detailed instructions, operators can achieve a reliable and efficient antenna setup that enhances their DXing and contesting capabilities.

40 Meter 2 element full size parasitic delta loop wire beam construction and switchable

A rugged motorized satellite antenna tracking system for construction by the home handyman

EH antenna for 160 mt: my experiment and comparison with a short vertical. with full details on construction procedure and testing.

The page describes two types of 2 meter J-Pole antennas, one made of copper pipe and a roll-up J-pole made of TV twin lead, providing dimensions, components, and construction details. It is authored by Dr. Carl O. Jelinek N6VNG.

PDF files describing how to homebrew a 1:2.5 balun

The RXO Unitenna, a vertical wideband antenna, offers operation across the 7-21 MHz spectrum, covering the 40, 30, 20, 17, and 15-meter amateur bands. This design focuses on achieving a low SWR across a broad frequency range, making it suitable for general HF operation without requiring an external antenna tuner for minor SWR variations. The antenna utilizes a unique loading coil and matching network to maintain efficient radiation characteristics across its operational bandwidth. Construction details within the PDF document include specific dimensions for the radiating element and the counterpoise system, which is critical for vertical antenna performance. The design incorporates readily available materials, simplifying the build process for radio amateurs. Performance graphs illustrate the SWR characteristics across the 7 MHz to 21 MHz range, demonstrating the antenna's wideband capabilities. The document also provides guidance on feedline connection and grounding considerations for optimal field deployment. This vertical antenna configuration is particularly useful for hams with limited space, offering a compact footprint compared to horizontal wire antennas.

The project details a DIY SWR/Wattmeter designed around an _Arduino Uno_ shield, providing capabilities to measure RF power from 2 to **200 watts** and Standing Wave Ratio (SWR) for HF amateur radio bands. This construction features a compact design, integrating the measurement circuitry directly onto a custom PCB that interfaces with the Arduino Uno microcontroller. Key components include a directional coupler for sensing forward and reflected power, precision rectifiers, and analog-to-digital conversion for processing RF signals. The Arduino firmware handles calibration, calculations, and displays the results on an integrated LCD, offering real-time feedback on antenna system performance. The design prioritizes simplicity for homebrewers. Performance specifications indicate accurate readings within the **2-200W** power range, suitable for typical QRP to medium-power HF operations. The project provides schematics and a basic overview of the software logic.

A new, revolutionary design allows the construction of small HF antennas, which provide the same efficiency as large antennas. This antenna can be built for all HF bands, from 10 to 80 m.

Here is a 70cm (440 Mhz) J-Pole antenna that is inexpensive, and easy to build. Author use 1/2 inch copper pipe, and the associated fittings necessary. The dimensions aren't typical however, this is what it took to get its SWR low.

Here's an award-winning, easy-to-homebrew, multi-band portable vertical antenna designed by long-time antenna aficionado James Bennett, KA5DVS. He documented the design and construction plans for a portable antenna that can be built with relatively ordinary components

This page details the construction of an easy-to-make collinear 360 degrees omni-directional, vertically polarised, antenna for 802.11b/g wireless networking.

The HB9CV-Beam is a 2-Element-Yagi with two driven elements and was introduced by Rudolf Baumgartner, HB9CV in the 1950ies. This beam antenna is a coax-feeded version of the ZL-Special construction by DK7ZB for 2m, 6m and 10m

Details the construction and optimization of antenna systems for amateur radio satellite operations, focusing on practical, homebrew solutions for VHF/UHF bands. It covers building _groundplane antennas_ from salvaged materials, recycling old beam antennas into new configurations like a 2-meter crossed yagi, and constructing a 10-meter horizontal delta loop. The resource also explains antenna matching techniques, including folded dipole driven elements and quarter-wave transformers, along with the importance of accurate SWR measurements and minimizing coax loss. Demonstrates how to achieve a **1:1 SWR** by carefully trimming elements and adjusting radial angles on groundplane antennas. It provides insights into selecting appropriate coax and connectors, highlighting the benefits of Belden 9913 for low loss and the proper installation of _N-connectors_. The article also addresses RFI mitigation from computer birdies and presents a design for a silent triac antenna control circuit, offering practical solutions for common satellite station challenges.

Javascript for calculating the lengths of tubing to be used for the construction of a Super J-Pole in a collinear design

This resource, last modified in August 2000, provides a personal amateur radio web presence for N3LS Larry, focusing on homebrew project announcements and a curated list of amateur radio links. It mentions plans for 10 to 15 new homebrew projects, indicating a focus on DIY electronics construction. The page also offers guidance for aspiring amateur radio operators, including tips for obtaining study guides and links to testing practice sites, suggesting an educational component for newcomers to the hobby. The content primarily serves as a personal hub, with a strong emphasis on sharing homebrew endeavors and supporting new licensees. While specific project details are not present, the intent to add numerous homebrew projects highlights a practical application of electronics knowledge. The inclusion of study resources aims to assist individuals in preparing for amateur radio license examinations, making it relevant for those seeking to enter the hobby.

813 Linear Amplifier Project includes many schematics, drawind and assembling construction

This article describes how to make a quadrifilar helix (QFH) antenna easily, from inexpensive materials: uPVC plumbing pipe and RG-58U co-axial cable. A low-cost, easy-to-build Quadrifilar Helix (QFH) antenna for weather satellite reception using uPVC plumbing pipe and RG-58U coaxial cable. Unlike traditional designs requiring copper pipe and plumbing skills, this approach enables construction with basic tools and minimal technical expertise. The antenna's shorter, wider proportions favor higher elevation angles, reducing interference from horizon-level pager transmitters. Electrical connections are simplified at the antenna's apex, with the coaxial cable forming the radiating elements. Testing demonstrated consistent signal strength throughout satellite passes, proving effective weather satellite reception is achievable without precision engineering to sub-millimeter tolerances.

Presents a collection of homebrew amateur radio projects and circuit ideas developed by EA5/G3PTO, a licensed operator since 1961. The resource details various transmitters and receivers constructed for frequencies ranging from 1.8 MHz to 10 GHz, emphasizing CW and BPSK31 operation. Specific projects covered include a "Bombproof 7Mhz Receiver" and several keying circuits, providing insights into designs that have proven effective over decades of use. The site also integrates personal photography, showcasing scenes from the West of England and Southeast Spain, reflecting the author's interest in connecting with other amateurs and visualizing their locations. Additionally, it offers a curated list of links to other home construction sites and DX information, serving as a hub for DIY enthusiasts and DXers. The content is distinctively personal, blending technical project documentation with a broader view of the amateur radio lifestyle and community engagement.

Examines the operational differences between **quad** and **Yagi** antenna designs, focusing on their respective performance characteristics for amateur radio applications. The document highlights key metrics such as forward gain, front-to-back ratio, and bandwidth, which are crucial for effective DXing and contesting. It discusses how element configuration, boom length, and material choices impact the efficiency and radiation patterns of each antenna type across various HF bands. Practical considerations for antenna builders are addressed, including structural integrity, wind loading, and overall weight, particularly when using fiberglass spreaders for quads. The resource also covers precipitation static reduction in quads due to their closed-loop design and their ability to operate efficiently at lower elevations compared to Yagis. It provides insights into dual-polarization feed systems for quads, offering independent vertical and horizontal feed points for enhanced operational flexibility.

Types of beverage wires, choose best supports and insulators, multiple antennas at one feedpoint, all well documented with photos and exaustive explanation. This article offers insights on building Beverage antennas for optimal reception. Key takeaways include using strong wire (copperweld or electric fence), proper termination, and a good grounding system (multiple copper rods). The author recommends maximizing antenna length and orienting it towards desired stations. For best results, utilize an antenna tuner and experiment with termination resistors.

50 MHz 1500 Watt Russian GS35B amplifier. Well documented. Complete construction details,pictures,schematics, and more.

The Flower Pot Antenna project details a portable dual-band antenna primarily operating on 10 meters, with secondary resonance near the 30-meter band. Construction involves winding RG58 coaxial cable uniformly around a large plastic flower pot, approximately 70cm high with a 60cm top diameter. The design eliminates the need for radials, contributing to its compact and lightweight nature. Key construction steps include soldering the inner conductor to the shield at one end of the wound cable and connecting the wound cable's shield to the rig cable's inner conductor at the base. An LC network, comprising a variable capacitor (0-200pF) and an inductor (10 coils, 5cm diameter, 2mm wire), is inserted between the wound cable's inner conductor and the rig cable's shield. Tuning is performed with an antenna analyzer, adjusting cable length and the variable capacitor for optimal impedance on 10 meters. The antenna performs effectively when installed horizontally.

Building a moxon antenna with aluminium tubes

Build the PAC-12 Antenna a multi-band portable vertical designed by KA5DVS, here's an award-winning, easy-to-homebrew, multi-band portable vertical antenna designed by long-time antenna aficionado James Bennett, KA5DVS. He's documented the design and construction plans for a portable antenna

The 80-meter loop antenna, measuring 86 meters (282 feet) of wire, effectively operates across 8 HF bands from 80 through 10 meters, despite its length being a compromise for specific bands. This design prioritizes a "low enough" SWR across multiple bands, aiming for lower SWR values on higher frequencies due to increased feedline losses. A 200-ohm feedpoint impedance provides a workable SWR on every band, with feedpoint impedances ranging from 100 ohms for lower bands to 300 ohms for higher bands. Radiation patterns for the 80-meter loop, mounted at 15 meters high, show a maximum gain of 7.6 dBi at a 90-degree takeoff angle on 80 meters, and up to 12.9 dBi at a 10-degree takeoff angle on 12 meters. This configuration supports regional contacts on 80 meters and provides good DX performance on higher bands. Practical construction notes emphasize using robust supports like trees, ensuring wire slack with _egg insulators_ for wind resilience, and employing an oversized 2 kW 4:1 _balun_ to safely handle higher SWR conditions, even with 100W transceivers. Feedline losses are minimized using _LMR-400_ coax or ladder line, with power transfer efficiency between 80% and 95%. Antenna simulations were performed using _xnec2c_, and the provided NEC file is compatible with other NEC2 derivatives. The antenna is tunable on 6 of 8 bands with an internal ATU and all 8 bands with an external autotuner like the LDG AT-200 Pro.

Step-By-Step Construction of a 4:1 Current-Type Guanella Balun by W1CG

This page describes the design and construction materials W8WWV used to build a coaxial cable trap. A coaxial cable trap is a parallel resonant circuit that is usually inserted in an antenna element to enable multiband operation.

Over 30 distinct shortwave (SW) receiver models are reviewed, offering insights into their performance, features, and user experiences. These evaluations, contributed by readers of the Usenet newsgroup **Rec.radio.shortwave**, cover a wide array of portable and tabletop radios, including popular units like the Grundig YB-400, Sony ICF-SW77, and various Realistic DX series models. Each review details aspects such as frequency range, tuning steps, SSB functionality, antenna performance, and construction quality, often comparing them to other receivers or ham transceivers like the Icom 725. For instance, the Grundig YB-400 review highlights its 144-30000 kHz AM/SSB coverage, direct keypad entry, and 40 station memories, noting its useful narrow bandwidth and tone switch for adjacent signal separation. It also discusses the **SSB mode** stability and the limitations of its 1 kHz frequency resolution for precise zero-beating. The review further details antenna performance, including the effectiveness of the built-in whip, the provided 7m reel antenna, and the potential for overload with larger outdoor antennas. Other reviews delve into specific issues, such as the Sony ICF-SW77's frequency display inaccuracies and timer malfunctions, or the Realistic DX-342's compact size and surprisingly good MW DXing capabilities despite its analog tuning. The collection provides practical, user-generated feedback on sensitivity, selectivity, audio quality, and ergonomic features, helping shortwave listeners understand the real-world performance and quirks of these receivers.

The resource provides detailed information about a five-band indoor magnetic loop antenna designed for amateur radio operators. This antenna is capable of operating on the 20, 17, 15, 12, and 10 meter bands, making it a versatile choice for various HF communications. Constructed from a single 3-meter length of 22 mm copper tube, the design emphasizes compactness and efficiency, which is particularly beneficial for operators with limited space. The page includes insights into the construction process, tuning, and operational tips, catering to both novice and experienced users. In addition to the technical specifications, the resource also discusses the advantages of using a magnetic loop antenna indoors, such as reduced interference and improved performance in urban environments. It serves as a practical guide for those interested in building their own antenna, offering a straightforward approach to antenna design and construction. Overall, this resource is a valuable addition to the toolkit of amateur radio enthusiasts looking to enhance their station with an effective indoor antenna solution.

Demonstrates the construction and on-air performance of the _NB6Zep_ antenna, a modified 20-meter Extended Double Zepp design optimized for multi-band operation from 40 through 10 meters. The resource covers basic design principles, including dimensions of 66 feet horizontal and 5 feet vertical elements, and specifies open ladder line or TV twin lead for the transmission line. It details material selection for low-cost wire antenna construction, such as 18 AWG wire for the legs and ceramic or plastic insulators, along with practical tips for soldering connections and insulating against moisture. The author, NB6Z, shares insights from extensive _EZNEC_ modeling to optimize the antenna's total length for a 40-meter half-wave dipole footprint and feed line length for direct tuner connection. The article presents field results, including successful _PSK31_ contacts from Oregon to the East Coast on 40 and 30 meters with 50 watts, even at a low height of 6 feet. It provides detailed performance characteristics for each band, noting the _NB6Zep_'s highest gain (over 3 dB) and sharp, medium-angle lobes on 20 meters, which yielded strong DX reports to locations like Korea, Japan, and Argentina. For 17 and 15 meters, it describes a butterfly-like pattern with broad lobes, while 12 and 10 meters exhibit narrow, directional lobes in an "X" configuration. The author also shares personal experiences operating successfully for over a decade in an antenna-restricted environment using the NB6Zep and other stealth wire antennas.

This page details the construction of a biquad antenna. The biquad antenna is easy to build, and provides a reliable 11dBi gain, with a fairly wide beamwidth.