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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.

Demonstrates the construction of **magnetic loop antennas**, detailing both multi-turn and single-turn designs. It covers a 30-inch diameter multi-turn loop for 80 meters, based on a February 1996 QST article, and an octagon single-turn loop made from 15mm copper tube with a 4.8-meter circumference, operating from 7 MHz to 14 MHz. The document also presents a smaller 800mm diameter loop for 14 MHz to 28 MHz, emphasizing the importance of high-voltage tuning capacitors. Covers the design and construction of custom **butterfly capacitors** and piston capacitors, including a split stator capacitor with 140 pF capacitance and a 6000 Volt rating, and a butterfly capacitor with 5-65 pF and 7200 Volt rating. It explains why butterfly capacitors are preferred over split stator types for high power applications due to lower losses and direct series connection of rotors, reducing resistive losses from wiper contacts. Material recommendations include clear PVC for plates and brass or stainless steel for non-magnetic hardware. Addresses practical considerations such as feeding the loop with a shielded 1/5 Faraday loop made from RG213 or RG8 coax, achieving VSWR 1.1 across bands, and optimizing its placement 180° from the capacitor. It also discusses mechanical joint resistance, dissimilar metal oxidation prevention using Vaseline, and a simple method for determining radiation angle with a TL-light tube. The guide includes diagrams for rotor, stator, and end plate construction.

The J-Pole Antenna Design Calculator, developed by K4ABT, G.E. "Buck" Rogers Sr., facilitates the rapid determination of J-Pole antenna dimensions for various amateur radio bands. Users input their desired operating frequency to generate specific measurements, enabling construction for HF, 2 meters, 220 MHz, 440 MHz, and higher frequencies. The tool supports designs using materials like aluminum or copper, offering flexibility for homebrew enthusiasts. Operational guidance includes recommendations for integrating a **choke balun** near the feedpoint to mitigate RF on the feedline, thereby improving SWR accuracy. For 2-meter operation, a suggested choke configuration involves four turns of coax with a 5-inch diameter, positioned within 3 to 4 inches of the feedpoint. Additional builder hints detail cost-effective construction methods, such as utilizing 1/2-inch EMT conduit and 1/4-inch soft copper for the 'J' section. The resource also references K4ABT's articles in CQ Magazine, specifically "The Packet Users Notebook," providing further technical context and design principles for antenna builders.

The "Mighty-Wide" six-meter dipole antenna, constructed from 300-ohm ribbon cable, features a total radiating element length of 2794 millimeters. It incorporates two shorting links placed 220 millimeters from each end and a 30 picofarad ceramic trimmer capacitor for impedance matching. The 50-ohm coaxial feedline connects 292 millimeters below the trimmer capacitor, eliminating the need for an external antenna tuning unit. This design provides a wide bandwidth from 50.00 to 52.00 MHz, making it suitable for the entire UK six-meter band allocation. Performance comparisons with a traditional coaxial dipole show superior **Standing Wave Ratio** (SWR) across the 50-52 MHz range, maintaining a low SWR without significant variation after initial adjustment at 51.00 MHz. The antenna's lightweight construction makes it ideal for **loft-mounted** or portable applications, and its folded dipole characteristics contribute to its wideband operation. The design is being considered for rescaling to WARC bands (12 and 17 meters) and 10 meters.

The HB9ABX mobile HF antenna, developed by _Felix Meyer_, offers a high-performance alternative to commercial mobile antennas for 80 through 10 meters. Constructed from fiberglass rods and enamelled copper wire, this design incorporates a loading coil with multiple taps, allowing for band-specific tuning. The article provides detailed instructions for winding the coil, connecting the antenna elements, and integrating it with a vehicle's chassis ground. Field tests conducted at 100W consistently showed the HB9ABX antenna outperforming a HUSTLER mobile antenna by up to **10 dB** (1 S-point) and a YAESU ATAS-100/120 by **18 dB** (2-4 S-points) across distances from 5 km to 1000 km. The design emphasizes a robust ground connection and the use of an antenna tuner, such as an _MFJ-901B_, for optimal SWR on all bands, particularly 40 and 80 meters. Initial adjustment involves setting whip length and coil tap positions to achieve resonance without a tuner, followed by fine-tuning with the tuner during operation. Specific measurements are provided for checking resonance on 21.0 MHz and 14.2 MHz, with precise turn counts for the lower (79 turns) and upper (120 turns) antenna sections. Safety precautions for handling fiberglass dust are also highlighted.

Details the construction of a J-vertical antenna specifically for the 10-meter band, offering a practical alternative to a _Slim Jim_ design for 28 MHz. The resource outlines the use of aluminum tubing for the half-wave vertical section and coaxial cable for the quarter-wave matching section, providing specific calculations for element lengths based on frequency and coaxial cable velocity factor. It contrasts the performance of the J-vertical with center-fed dipoles and end-fed verticals, noting superior results in previous comparisons. The article further presents a more recent iteration of the J-vertical, constructed using a fiberglass pole and insulated wire, with updated dimensions for 28.8 MHz. It includes practical advice on weatherproofing connections and securing the antenna for durability against adverse conditions, referencing the survival of an original _J Vertical_ during 110 MPH winds in 1987. The SWR performance is reported as 1.1:1 at 28.6 MHz, maintaining below 1.5:1 across 28.3 to 29 MHz.

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.

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.

Demonstrates a **shunt-feed** matching technique for Hustler mobile HF antennas, specifically the MO-3 mast with RM series resonators, to achieve optimal **SWR** on the 40-meter and 20-meter bands. It details the construction of a loading coil using 20 turns of #12 solid wire, 1.25-inch ID, spread to 5 inches, and provides tap points: 8 turns for 40m and 4 turns for 20m, connecting one end to the feed point and the other to ground. The resource presents specific SWR results, noting a 1:1 match at 7.258 MHz on 40m and 14.275 MHz on 20m, with SWR remaining below 1.5:1 across significant portions of the General phone segments. It highlights a noticeable improvement in both transmit and receive performance compared to a straight antenna setup, emphasizing the practical application of this matching method for mobile installations, particularly on a fender-mounted ball mount.

Presents a practical design for a **crossed-dipole turnstile antenna** specifically engineered for 2-meter Amateur Radio Direction Finding (ARDF) events. The author, WB6RDV, details a robust, omnidirectional, horizontally-polarized antenna, addressing the international ARDF rules requiring such characteristics at a height of two to three meters above ground. This contrasts with the vertical polarization often used in Southern California, highlighting the design's adherence to specific event requirements. The electrical design employs a classic crossed-dipole with a 75-ohm phasing section, resulting in a slight impedance mismatch and an SWR of approximately 1.3:1 with a 50-ohm feedline. Construction utilizes readily available and inexpensive PVC plumbing components and 1/8-inch bronze welding rod for elements. The guide provides step-by-step instructions for mechanical assembly, including drilling element holes at precise 90-degree spacing and preparing the RG-179 matching section. WB6RDV shares insights from his own build experience, discussing the use of plated brass versus aluminum spacers for element attachment and the effectiveness of crimping as an alternative to soldering. The document also covers final assembly, including the integration of ferrite beads as a choke balun and options for weatherproofing and alternative mounting configurations, emphasizing the adaptability of the design for other VHF bands through scaling.

A 1.5-meter telescopic whip antenna project for the Yaesu FT-817 QRP transceiver is presented, offering a cost-effective alternative to commercial portable antennas like the Whip Miracle. The design incorporates a **toroidal matching unit** with a rotary switch for band selection and a toggle switch for fine-tuning the coil taps. This setup allows operators to achieve a low **Standing Wave Ratio (SWR)** across various HF bands, despite the inherent limitations of a physically short radiator on lower frequencies. The construction details include photographs of the completed unit, showcasing the compact enclosure and the integration with the FT-817. A simple schematic illustrates the coil tapping arrangement and the switching mechanism, guiding hams through the assembly process. The project emphasizes practical, portable operation for **QRP** enthusiasts, acknowledging that while performance on bands like 80m or 40m will be modest, it can still facilitate contacts under favorable conditions with skilled operation.

Building a directional antenna for limited space, M0MRR shares his experience constructing a 10-meter Moxon rectangle. Initially using fiberglass fishing poles and a plastic breadboard, he achieved a 1:1.2 SWR across the band with 50 watts, making contacts as far as PY2TO from the UK. The design incorporates 10-amp power cable for elements and RG58 coax with crocodile clips for feeding, demonstrating a cost-effective approach. His field observations confirm the directional properties, noting European signals fading when facing Stateside, and receiving better reports from stations in the antenna's favored direction. While not formally measured, the front-to-back ratio appears effective. The initial build was somewhat flimsy, intended for temporary deployment, but proved effective for DX. Later, M0MRR constructed a more robust 10-meter Moxon using tubular aluminum pipe, indicating an evolution in his design approach for durability. The project highlights practical antenna building for small backyards, emphasizing the benefits of a directional antenna even with modest power.

The _Morgain_ antenna for 40/80 meters is a straightforward and cost-effective wire antenna design, requiring careful tuning for optimal performance across two bands with low SWR. Construction involves creating 12 cm PVC spacers with three holes for wire insertion, along with larger terminals for anchoring and connector housing, which should be sealed with silicone. The provided measurements detail the specific lengths for the antenna elements, crucial for achieving resonance on both 40m and 80m bands. Tuning the Morgain antenna necessitates fabricating four wire segments with pins to temporarily connect and adjust the bridging points symmetrically for both 40m and 80m. This iterative process, though time-consuming, ensures the antenna functions effectively for decades once the precise connection points are soldered and protected. The design emphasizes ease of construction and long-term stability, making it a practical solution for hams seeking a dual-band wire antenna.

The 20-meter homebrew **Moxon antenna** project by 9Y4DD, Dave, details the construction of a 14 MHz directional antenna using readily available and repurposed materials. Initial SWR readings at 6 feet were 1.2 at 14.000 MHz, 1.4 at 14.350 MHz, and 1.1 at 14.175 MHz, with a subsequent increase of 0.1 on all frequencies when raised to 15 feet. The design adheres to specifications provided by L.B. Cebik (W4RNL). Key components include a discarded domestic water pump pressure tank as the center mounting bracket, 1/2-inch PVC conduit for spreaders, and 1/2-inch CPVC hot water pipe inserts to enhance rigidity. The total weight of the antenna is 12.625 pounds, with a material cost of U.S.$36.63. The spreaders are 165 inches from the center, utilizing 2.5mm sq. stranded copper wire for the elements. Dave's design incorporates hexagonal 'spider webs' of waxed twine to stabilize the flexible PVC spreaders, addressing initial issues with wind-induced movement. Separators cut from 3/16-inch Plexiglas maintain an 8.6-inch element spacing. The antenna demonstrated effective DX contacts with Europe from Trinidad, showing improved noise reduction compared to an inverted V.

The article details the construction of a "bug-catcher" style HF mobile antenna, emphasizing its low cost and ease of tuning. It outlines the use of readily available materials such as PVC pipe, #14 house wire for loading and matching coils, and a _RadioShack_ replacement whip antenna. The design allows for operation across 20 through 6 meters, achieving an SWR of **1.5:1** or less on each band segment. The resource provides a comprehensive materials list, step-by-step assembly instructions, and photographs illustrating key construction phases. It explains how to create the coil forms, wind the coils, and secure them with epoxy putty. Crucially, the guide includes a table of suggested coil-tap positions and whip extensions for specific bands, such as 6 turns on the matching coil and 8 turns on the loading coil for 20 meters, facilitating initial tuning. Furthermore, the document discusses installation considerations, including grounding, and offers practical advice for tuning the antenna using an SWR meter. It highlights the antenna's broadband characteristics and its ability to collapse the whip for garage storage, making it a practical solution for mobile HF operation. The author, KM4IE, shares personal experiences with worldwide CW and phone contacts using this antenna.

Presents a detailed construction guide for a 2-element _Moxon rectangle_ antenna optimized for the 10-meter band, designed by L. B. Cebik, W4RNL (SK). This resource demonstrates how to build a compact beam antenna using readily available hardware store aluminum tubing, fitting within a 12-13 foot width. It highlights the antenna's performance characteristics, including a gain comparable to a 2-element Yagi (11+ dBi) and a front-to-back ratio exceeding 20 dB between 28.3 and 28.5 MHz, with an SWR below 2:1 across the entire band. The design emphasizes direct 50-ohm coax connection without a separate matching system, though a 1:1 choke _balun_ is recommended. The guide provides practical advice on element construction, corner fabrication using L-stock or radius-bent tubing, and the critical side-to-side length adjustment for SWR optimization. It details the feedpoint assembly using a chassis-mounting coax connector and discusses element-to-boom plate options, including spar varnished plywood or LE plastic. The author's experience with a test model on a 20-foot mast confirms stable feedpoint characteristics and excellent performance even at lower heights. The document also includes insights into the antenna's free-space azimuth patterns, noting a broad forward lobe and significant front-to-back rejection. It contrasts the Moxon with traditional Yagis, positioning it as an effective, home-buildable alternative for compact sites or _Field Day_ operations, particularly beneficial during periods of increased 10-meter activity.

The KD6WD Moxon Antenna Project details the construction of 50-ohm two-element wire beam antennas, specifically Moxon rectangles, for the 10, 15, 17, and 20-meter bands. It utilizes AC6LA's software for critical measurement calculations (A-E) based on center frequency and wire size. Construction involves 16-gauge silver-coated copper wire, 16-foot telescoping fiberglass crappie fishing poles as spreaders in an "X" configuration, and various hub designs including aluminum tubing or PVC joints. A 1:1 current balun is used at the feedpoint, with wire nuts for connections, often achieving a 1:1 SWR across the design band. The project highlights practical applications, such as running a kilowatt into the antennas for greyline DX contacts, consistently yielding excellent signal reports. Comparisons to quad loops show 4 to 5 S-unit improvements in both receive and transmit. The Moxon design, according to L.B. Cebik's analysis, offers superior forward gain and front-to-back ratio among wire beams. The author notes a "DX-Vane" effect where a freely suspended Moxon automatically points to the strongest DX signal. Attempts at dual-band operation (17/20 meters) with a single feed were unsuccessful, reinforcing the Moxon's monoband nature, with EZNEC plots provided for a 17-meter Moxon at 30 feet.

SM0DTK's 40-meter Moxon antenna project details the construction and deployment of a wire Moxon rectangle, specifically dimensioned for the 7 MHz band. The resource outlines the use of a _Moxon Rectangle Generator_ for calculating wire lengths and the fabrication of plexiglass supports for corners and the feeding point. It describes the practical challenges of elevating the antenna to approximately **14 meters** using an aluminum tube and fiberglass rod, emphasizing the adjustment process for achieving the correct rectangular shape. The article presents comparative results against a 60-meter long-wire and a full-size 40-meter ground plane antenna. The Moxon demonstrated significant directional gain towards the west, facilitating DX contacts in the Caribbean with **100 watts**, while simultaneously reducing QRM from strong eastern European stations. The SWR was reported as perfect without the need for an antenna tuner, validating the design's effectiveness for targeted signal enhancement and interference mitigation.

WB2VUO presents a practical examination of effective HF mobile antennas, focusing on the inherent efficiency challenges encountered on the lower bands, specifically 160, 80, and 40 Meters. The resource delves into the necessity of loading coils for mobile operation below 21 MHz, where full-sized antennas are impractical. It contrasts base-loaded and center-loaded designs, noting that base-loaded antennas are simpler for the average ham to construct but offer lower efficiency compared to center-loaded configurations. The author provides specific data for an 8-foot whip, detailing its electrical length and _radiation resistance_ across various HF bands, from **0.08 ohms** on 160 Meters to **16.1 ohms** on 12 Meters. This data highlights the extremely low radiation resistance on lower frequencies, which significantly impacts feedpoint impedance due to ground and feedline losses. The discussion includes practical considerations for feedpoint impedance, noting that a typical 8-foot whip on 10 Meters might present 30-45 ohms, allowing for acceptable SWR without an ATU. Construction sketches illustrate both base-loaded and center-loaded mobile antennas, with advice on material selection like galvanized steel for rugged bottom sections. The article also includes coil value charts from the _ARRL Mobile Manual_ for both base and center loading, emphasizing the importance of using large diameter wire to minimize losses and suggesting capacity hats to reduce coil inductance and improve performance on 160-40 Meters.

A 70 MHz Moxon rectangle antenna, built with 0.83mm enamelled copper wire and a lightweight fiberglass kite spar frame, offers a compact two-element beam solution for the 4-meter band. This design, originally for HF, scales effectively to VHF, reducing the antenna's width to approximately 75% of a half-wavelength while allowing direct coaxial cable feeding. The author, G6GVI, details the construction process, including the use of an automated design tool for precise dimensions. Initial field testing revealed a VSWR of approximately 1.3, with distinct nulls observed at 90 degrees when the antenna was mounted horizontally. The lightweight build, supported by a wooden block and U-bolt for mast attachment, makes it suitable for thinner mast sections. Further experimentation included testing with vertical polarization and considering its potential for indoor loft installation due to its relatively short major axis, offering a discreet option for urban hams.

Indoor multiband dipole with EZNEC data files for simulation and analysis. Includes details on construction, tuning, SWR plots, and software usage. This page includes two different dipoles, a first version for 20-10 meters and an extended version covering 40-10 meters allowing a full coverage of most used ham radio HF Bands.

This resource details the construction and feeding of a vertical Moxon antenna specifically designed for the 20-meter band (14 MHz). It addresses the common issue of impedance variations at the feed point of vertical dipoles and Moxons, which typically requires the coax to exit at a specific angle (45-90 degrees) to maintain a good 50-ohm match. The presented solution involves opening the lower corner of the fed element and utilizing a transformer for impedance matching, simplifying installation and improving SWR. The alternative feeding method provides a stable match, eliminating the need for precise coax routing to achieve a low SWR. This design offers a practical improvement over conventional vertical Moxon feeding, making deployment significantly easier. The author, SM0DTK, confirms the efficacy of this setup, noting its fine performance and reduced installation complexity compared to traditional methods.

The KD1JV "Melt Solder" Digital QRP SWR/Power Meter operates across the 160m to 6m bands, featuring 9.9-watt and 990-milliwatt power scales, a peak hold mode for SSB, and a VSWR scale from 1:1 to 9.9:1. It utilizes a _Stockton directional coupler_ wound on a single binocular core and an _Atmel AVR ATtiny26L_ microcontroller for processing. The design incorporates _W7EL diode compensation_ in a non-inverting amplifier feedback loop to address diode voltage drop and non-linear behavior at low power levels, with software corrections applied for improved accuracy, particularly at QRP power levels up to 5 watts. Construction details include parts placement, transformer winding instructions for #26 magnet wire, and calibration procedures using a 1.5V alkaline battery or an oscilloscope with a 50-ohm dummy load. Packaging options are discussed for fitting the board into an Altoids tin or a deeper Whitman’s Sampler tin, with considerations for battery life extension by adding a third or fourth battery. Accuracy tests performed at 7 MHz compare readings against a True RMS power meter based on an _Analog Devices AD8361_ chip, showing typical deviations of 0-5% across various power levels.

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

Presents the design and construction details for a VHF bicycle-mobile antenna, originally published in QST. The antenna utilizes a modified _Arrow J-Pole_ design, adapted for portable operation on a bicycle frame. Performance characteristics include a reported **1.5:1 SWR** across the 2-meter band, demonstrating effective impedance matching for typical handheld transceivers. Construction involves readily available materials, emphasizing lightweight components suitable for mobile deployment. The document provides a parts list and step-by-step assembly instructions, detailing the radiator and ground plane element lengths for optimal resonance at 146 MHz. Mechanical considerations for mounting on a bicycle are also addressed. The resource covers practical aspects of integrating the antenna with a bicycle, including cable routing and securing methods. It offers insights into achieving reliable VHF communications while operating in a mobile, low-power environment, making it relevant for field day activities or casual portable operation.

The **NW3Z** optimized wideband antenna designs, originally presented at Dayton 2001, detail Yagi configurations for the 20-meter, 15-meter, and 10-meter amateur radio bands. This resource provides access to the design files, likely containing critical parameters such as element spacing, element lengths, and boom dimensions, which are essential for replicating these directional antennas. The designs focus on achieving wide bandwidth, a desirable characteristic for contesters and DXers operating across a significant portion of each band. The content specifically references "nw3z-Antenna-DesignsDownload," indicating that the core information is available as a downloadable file, presumably in a format suitable for antenna modeling software or direct construction. Such files typically include **NEC models** or similar data, allowing for performance analysis and optimization before physical construction. The emphasis on "optimized wideband" suggests design considerations for SWR bandwidth and gain characteristics over a broader frequency range than typical narrow-band Yagis. The resource serves as a direct source for specific, proven antenna designs from a known amateur radio antenna designer, offering practical data for hams interested in building high-performance Yagi arrays for HF.

The K5OE 2-meter vertical mobile antenna design, detailed in this resource, employs a 3/8-wavelength vertical section complemented by four shortened radials, forming an off-center-fed vertical dipole. This configuration creates a self-contained lower half, enhancing efficiency compared to traditional 1/4-wave monopoles relying on vehicle bodies for a ground plane. The article specifies construction using PVC components, 10-gauge insulated wire for elements, and provides precise dimensions in both inches and centimeters for the 25-3/16" (64 cm) vertical and 7-3/16" (20 cm) radials. Performance data indicates an honest 3 dBi of gain at 6 feet elevation (2 dBi free-space), with a pattern favoring the horizon, suitable for Low Earth Orbit (LEO) satellite communications. At 20 feet high, the same antenna exhibits almost 6 dBi of gain, with a nominal 50 Ohm feedpoint impedance at 146.850 MHz. Tuning instructions involve trimming element lengths, with the author achieving a 1.2:1 SWR by pruning the mast to 24-3/4" and radials to 7". The resource highlights the antenna's effectiveness for mobile LEO satellite uplinks, particularly at low elevations, and its suitability for fixed, mobile, or portable operations. The flexible wire elements allow for easy folding, making it a practical choice for backpacking. The original design by K5OE was previously hosted on aol.com.

The resource details the construction and performance of a dual-band 40/30 meter _Moxon_ antenna, evolving from an initial single-band 30-meter design that failed in a storm. It specifies materials such as four 10-meter fishing rods, galvanized iron TV antenna support pipes, 1mm diameter PVC-covered copper wire, and a piece of 75-ohm TV satellite cable for feedline. The document outlines the iterative design process, including initial resonance measurements of 9.9 MHz for 30 meters and subsequent recalculations to shift the center frequency by 300 kHz using _Moxon software_. Initial testing on a roof yielded SWR readings of 1.4:1 at 7.200 MHz and 1.5:1 at 10.280 MHz. After installation atop a 30-meter tower, the final SWR measurements were 1.1 at 7.130 MHz and 1.4 at 10.230 MHz, with a notable 30 dB front-to-back ratio on 40 meters. The 30-meter performance, while good, showed a front-to-back ratio of approximately 15 dB, suggesting a slightly high resonance. The antenna's placement on a 700-meter hill, with a significant ground drop in certain directions, is noted as a potential factor in its excellent DX performance, enabling daily contacts with the USA West Coast on 30 and 40 meters with 100 watts.

The ARRL ANTENNA Vol 5 COMPENDIUM features an article detailing two portable 6-meter antennas: a 2-element quad and a 3-element Yagi with telescoping elements. The 2-element quad exhibits a measured gain of **4.2 dB** over a dipole, while the 3-element Yagi achieves **5.8 dB** over a dipole. Both designs prioritize ease of construction and rapid assembly/disassembly for portable operations. Specific dimensions are provided for a 3-element 6-meter quad using #14 bare copper wire. The reflector element diameter is 6.2958 meters, the driven element 6.125 meters, and the director 5.8547 meters. Element spacing is 0.9398 meters between reflector and driven, and 1.1684 meters between driven and director. The SWR is under _1.26:1_ from 50 to 50.4 MHz, with a feed point impedance of 48.75 -j0.13 Ohms at 50.2 MHz, suitable for direct 50 Ohm coax feeding with a current _balun_.

A rotary trapped-dipole for 17 and 20 meters, as described by IZ7ATH, presents a practical solution for multi-band HF operation. The author, Talino, recounts his experience building this antenna for IK7ZCQ, detailing the evolution from an initial concept involving a grounded-driven element and gamma-match to a direct-fed, non-grounded design. His pragmatic approach, adapting available materials, is evident throughout the construction narrative, particularly with the use of eight tapered aluminum pipes for the driven element. Construction specifics include precise measurements for the aluminum tubing, with diameters ranging from 30 mm down to 16 mm, and a critical note on reducing tip thickness for weight optimization. The _traps_, initially a concern, are fabricated using 8 turns of RG58 coax on a 27 mm support, tuned to resonate at 18.1 MHz using a dip-meter. Talino emphasizes sealing the traps with RF glue and PVC tape to prevent water ingress, a crucial step for longevity. Field test results, conducted on a 10-meter pole in a clear garden environment, showed an SWR of 1.2:1 on 17 meters and 1.5:1 at 14.200 MHz. While SWR varied slightly when installed at Mario's QTH due to nearby objects, the antenna's performance remained commendable. The final half-dipole length is 46 cm for the 18 MHz tips, and the total weight is under 6 kg, with potential for further reduction.

MoxGen is a **Windows** application designed to calculate dimensions and generate antenna model files for 50-ohm **Moxon Rectangle** antennas. Users input the desired design frequency in MHz and the wire size (AWG or diameter in inches/mm), and the software outputs the precise element lengths, spacing, and overall dimensions required for construction. It also creates a .maa file compatible with EZNEC, enabling further analysis and optimization of the antenna's performance characteristics. The software provides a visual representation of the Moxon rectangle, displaying key parameters such as gain, front-to-back ratio, and SWR at the design frequency. This allows radio amateurs to quickly assess the potential performance of their proposed antenna before physical construction. The generated EZNEC model facilitates detailed pattern analysis, impedance matching, and interaction with surrounding structures, proving useful for both initial design and fine-tuning.

This resource presents a detailed analysis of the W6NL 2-element 40-meter **Moxon Yagi** antenna, covering its design, construction, and measured performance characteristics. It outlines key specifications such as a free-space gain of 6 dBi, 11 dBi at 70 feet, and a direct 50-ohm feed. The document highlights the antenna's physical attributes, including 52-foot elements, a 27-foot boom, and a weight of 75 pounds, engineered to withstand 125 mph winds. Modeling was performed using **AO6** and K6STI software, with a focus on the unique functions of the transverse tip elements for Moxon coupling, physical balance, efficient capacitive loading, and reduced wind load. The presentation includes comparative data, showing the Moxon's superior front-to-back (F/B) ratio and wider bandwidth compared to traditional loaded Yagis. Performance graphs illustrate the SWR, gain, and F/B across the entire 40-meter band (7.0-7.3 MHz), comparing measured results against calculated values. Azimuth and elevation patterns demonstrate high F/B, with the antenna's pattern matching that of a full-size 3-element Yagi on a 30-foot boom. It also notes a gain difference of 1.5 dB down relative to a K3LR 4-element Yagi on a 50-foot boom, providing practical benchmarks for performance evaluation.

Details the construction of a portable _Moxon_ antenna optimized for the 2-meter band, utilizing readily available materials like 6.5 mm aluminum elements and a 15x15 mm TV boom. The design emphasizes ease of assembly and portability, making it suitable for field operations. Performance specifications derived from MMANA modeling indicate a forward gain of **6.3 dBi** and a front-to-back ratio of **15 dB**. Lateral attenuation is reported at 40 dB, with a minimum SWR of 1.1 at 144.300 MHz, confirming efficient operation within the target frequency segment. The antenna is lightweight at 500 grams, quickly assembled in approximately two hours, and disassembles into a compact 40x15x8 cm package. Direct feeding with RG-58 C/U or KX-15 coaxial cable via a BNC connector simplifies deployment.

SWR and RF power meter for home usage, 8 different RF probes with different characteristics and power ranges by OK1DX

The "Largest YU Moxon" document meticulously details the design and construction of a substantial multiband Moxon antenna, primarily for 80m, 40m, and 20m operation. It presents specific design parameters derived from NEC-based simulations, including a 4-element 80m Moxon with 37 dB F/B and 7.81 dBi gain on a 47m boom, a 4-element 40m Moxon with a bidirectional pattern, and a 6-element 20m Moxon optimized for specific side lobes. The resource provides precise element lengths and spacing in meters for each band, alongside measured SWR results across the 3.650-3.800 MHz, 7.000-7.100 MHz, and 14.000-14.350 MHz segments. The construction narrative outlines the challenges and solutions encountered by the YU team, including the use of trees for support, the creation of "ugly" air-choke baluns from RG-58 cable wound on plastic bottles for each band, and the meticulous process of attaching wires to a rope boom. It documents the physical dimensions of the vineyard site (47 x 38m) and the azimuth orientation (340 degrees) chosen for the antenna. The document is distinctively useful for its practical insights into large-scale antenna deployment in a field environment, offering real-world SWR measurements and anecdotal performance reports from CQWW contest operations. It includes numerous photographs illustrating the construction process, the team members, and the finished antenna structure, providing visual context to the technical details.

Details a practical QRP wattmeter construction, leveraging a simplified SWR meter design by JA6HIC. The project focuses on a forward-only power measurement circuit, providing a functional instrument for RF power levels from milliwatts up to 5 watts. It maintains a 50-ohm input and output impedance, suitable for typical QRP transceivers and antenna systems. The resource includes the schematic for the "VSW" (Very Simple Wattmeter) and outlines a six-step alignment procedure. This calibration process involves using a known RF source up to 5W, setting full-scale deflection, and marking power increments. It also addresses minimizing frequency effects on readings with a 100pF trimmer capacitor, noting that measurement error is highest at the lower end of the scale. Construction notes mention using a piece of RG-213 coaxial cable for the inductance and coupler, with the wattmeter assembled in early 2003. The author provides an example measurement showing 0.8W into a dummy load and 1W into a 3-element beam.

Over 75 years of engineering expertise underpins Bird Electronic's offerings in RF power measurement, critical for maintaining peak performance in amateur radio stations and professional communication systems. The company specializes in a range of test equipment, including wattmeters, SWR meters, and antenna analyzers, essential for optimizing antenna systems and ensuring efficient power transfer. Their product line extends to various RF components such as filters, cables, and connectors, all designed to meet stringent technical specifications for reliability and accuracy across diverse frequency bands. Bird Electronic's instruments, like the _Bird 43_ Thruline Wattmeter, are widely recognized for their robust construction and precise measurement capabilities, providing hams with confidence in their station's operational parameters. These tools enable accurate assessment of forward and reflected power, SWR, and modulation characteristics, which are vital for troubleshooting and maximizing radiated power. The company's commitment to innovation ensures that its products remain relevant for modern RF challenges, from HF through microwave applications, supporting both traditional analog and advanced digital modes.

Presents the design and construction of an automatically tuned 7-30 MHz mobile HF vertical antenna, originally published in _QEX / Communication Quarterly_ in 2003. The resource details a base-loaded vertical antenna system that mounts on a vehicle's roof, incorporating a variable inductor as its loading coil. A three-legged chariot, driven by a modified model airplane servo, travels inside the coil to adjust inductance. The control unit, featuring a _Basic Stamp microcontroller_ and SWR sensor, emulates a Kenwood AT-50 tuner for seamless integration with a _Kenwood TS-50_ transceiver, allowing automatic tuning across all ham bands from 40 to 10 meters. The project emphasizes practical application, providing a solution to the narrow-banded nature of mobile HF antennas and the inconvenience of manual band changes. It achieves a maximum SWR of 1.3:1 across its operating range. The mechanical design is thoroughly documented with detailed drawings, including a full-resolution GIF and AutoCAD R14 DWG files, illustrating components like the stainless steel whip, PVC coil tube, and the servo-driven chariot mechanism. Construction requires a lathe, but the author notes it can be accomplished with a hobby lathe, making it accessible to those with moderate mechanical skills.

This PDF document, authored by KT4QW in October 2004, details the construction and modeling of a dual-band, horizontally polarized hanging rectangular loop antenna for **10 and 17 meters**. The design, adapted from *The ARRL Handbook*, utilizes _NEC4WIN95_ software for scaling and optimization, targeting a 50 ohm feedpoint impedance. The resource includes a bill of materials, step-by-step construction instructions, and a discussion of the antenna's radiation characteristics. It presents NEC-generated elevation and azimuth patterns, comparing the loop's performance to a half-wave horizontal dipole at the same height and frequency. The 17-meter element is centered at 18.140 MHz for low SWR across the phone band, while the 10-meter element is centered at 28.500 MHz. Construction involves 14-gauge stranded copper wire and Schedule 40 PVC spreaders, with the total wire length calculated by the formula: Length in feet = 1005/MHz. The feedpoint impedance can be adjusted by modifying the rectangular aspect ratio. The document specifies hoisting the antenna to at least a half-wave above ground for testing. It notes that a balun was tested and found to have no measurable effect on SWR or radiation characteristics. A 2-meter scale model is presented to illustrate the physical design, and a "rotator" string is incorporated for directional adjustment up to 90 degrees.

This technical note explores the application of **Moxon rectangle** antennas for WARC bands, specifically 17 and 12 meters, as compact directional alternatives to standard Yagis. It details three design approaches: a dual-band Moxon using open-sleeve coupling, a Moxon-Yagi combination, and a simplified 1.5 Moxon rectangle. The document provides specific dimensions in feet for aluminum tubing elements (0.75" and 0.5" diameter) for each configuration, along with projected free-space gain, front-to-back ratio, and feedpoint impedance (R+/-jX Ohms) across the respective band segments. Performance tables illustrate gain (dBi), front-to-back ratio (dB), and 50-Ohm VSWR for each design. The dual-band Moxon, despite its compact 7-foot boom, is not recommended due to extreme sensitivity to construction variations, leading to rapidly changing performance characteristics. The Moxon-Yagi combination, featuring a 17-meter Moxon and a 12-meter director-driver Yagi, is presented as a more practical and adjustable solution, offering stable performance with a 10-foot boom. NEC model descriptions are included for simulation in programs like EZNEC, NEC-Win Plus, AO, or NEC4WIN.

An experimental antenna, similar to the _TAK spiral antenna_, was evaluated for SWR response over the 7.0 to 7.3 MHz frequency range. The analysis presents specific results: beam length significantly affects SWR, with increased distance between spirals raising the resonant frequency; the combined length of antenna and hookup wire lowers the resonant frequency as it increases; and spiral diameter impacts bandwidth, with larger diameters yielding greater bandwidth. The design addresses the fixed beam length limitation of the commercial TAK antenna by introducing an adjustable version constructed primarily from PVC electrical conduit and water pipe, using 14-gauge aluminum wire. The resource includes a detailed mechanical design, construction steps, and a parts list. It also features a spiral antenna spreadsheet model for calculating design parameters like start point, pitch, safe edge, spoke length, and arm length, which aids in determining wire length and kerf cutting tables. Model verification involved constructing an antenna to specific parameters, with SWR tests conducted using an _MFJ Model 269_ antenna analyzer at 13 feet above ground with 60 feet of RG8 mini coax. Measurements showed that adjusting beam length from 27 to 37 inches shifted the resonant frequency by approximately 0.18 MHz. Further data compares 32-inch versus 48-inch diameter spirals, demonstrating increased bandwidth for the larger diameter. The model accurately predicted revolutions for given antenna lengths, pitch, and starting distances. The final design achieved a resonant frequency of 7.17 MHz, favoring the voice portion of the 40-meter band after adjustments.

Constructing a compact, two-band magnetic loop antenna for HF operation, especially from constrained locations like a balcony, presents unique challenges. OK1FOU's design, inspired by DJ3RW's 50 MHz loop, addresses these by employing an unusual side-fed configuration and placing the symmetric, two-section variable tuning capacitor at the bottom of the loop, directly connected to the coax shield. The article provides specific material recommendations, including two 1-meter wooden pales and about 3 meters of thick loudspeaker cable, noting the high current (60A at 100W) in the loop. Construction steps detail forming two turns with a 5 cm gap, using a GDO to pre-tune the open loop to a frequency slightly above the desired highest band, and then integrating the tuning and coupling capacitors. For 10/14 MHz, an open loop resonance of 16-17 MHz is suggested. Practical experience with the 10 MHz band from a third-floor balcony in Prague (JO70GC) shows a 1:1 SWR across most of the band without an external ATU. While DX traffic was modest due to the urban environment, QSO examples with RA6WF, LA6GIA, G0NXA, and LZ1QK on 10 MHz are provided, demonstrating its operational capability.

Demonstrates a practical modification to convert a standard G5RV antenna into a _160-RV_ for effective operation on the 160-meter band. This project addresses the challenge of achieving Top Band resonance with a common multi-band wire antenna, providing a solution for hams with limited space or resources for dedicated 160m antennas. The design utilizes a specific length of 450-ohm ladder line and a 1:1 current balun, acting as a matching section to bring the G5RV's impedance into a usable range for 1.8 MHz. The document includes a parts list, detailed construction steps, and tuning instructions, emphasizing the importance of precise measurements for the ladder line and coaxial cable sections. It also outlines the expected SWR characteristics and power handling capabilities, making it suitable for QRO operation up to 1.5 kW. The _AD1B_ design offers a straightforward approach for extending the utility of an existing G5RV.

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

This project outlines the construction of a 3-element reversible quad antenna specifically designed for the 40-meter band. The materials required include pushup towers, pressure-treated posts, insulated wire, and various electrical components such as relays and a balun. The construction process is straightforward, beginning with the installation of the posts in a straight line, followed by the assembly of the antenna elements and their elevation to the desired height. The antenna's design allows for directional signal reception, making it ideal for operators looking to enhance their communication capabilities on the 40-meter band. The project includes detailed instructions on tuning the antenna for optimal performance, ensuring that operators can achieve the lowest SWR possible. Additionally, the design can be adapted for other bands by extrapolating dimensions, providing versatility for amateur radio enthusiasts. Overall, this reversible quad antenna project is suitable for both beginners and experienced operators, offering a practical solution for improving signal strength and directionality in 40-meter communications.

The K0RWU 75-meter mobile antenna design features a 7.5-foot overall length, incorporating a 2.5-foot loading coil wound with #20 enamel wire on a 1/2-inch fiberglass rod, subsequently covered with 1/2-inch shrink tubing to increase diameter to 3/4 inch. This configuration achieved resonance at 3965 kHz with a 5-foot stainless steel whip. The antenna integrates a matching transformer, identified by larger turns near the PL259 connector, and is constructed using a modified Radio Shack CB antenna base. Construction involves drilling and epoxying a 1/2-inch fiberglass rod into a PL259 connector, feeding #20 enamel wire through the rod, and winding 17 turns of #18 matching coil wire between the PL259 sleeve and the center feed point. The main loading coil fills the 2.5-foot rod section. The design allows the antenna to bend for garage clearance and emphasizes maintaining a 50-ohm feed impedance to prevent vehicle electrical damage. The author also discusses experiences with a Yaesu ATAS-100 motorized antenna and a 10-meter antenna project, noting issues with auto couplers and the ATAS-100's performance on 17 meters. Future modifications considered include adding a small servo for band spreading and increasing the fiberglass rod length for a 3-foot loading coil to improve bandwidth. The antenna's sharp tuning, between 3960 kHz and 3970 kHz, necessitates careful adjustment of coil turns for optimal VSWR.

A 20-meter Moxon antenna design provides a compact directional solution for the 14 MHz band, achieving approximately **5.5 dBi** of forward gain and a front-to-back ratio exceeding 20 dB. This rectangular wire array, consisting of a driven element and a reflector, offers a smaller footprint than a traditional 2-element Yagi, making it suitable for space-constrained installations. Construction details focus on specific dimensions for the wire elements, fed with 50-ohm coaxial cable. The _Moxon rectangle_ inherently delivers wide bandwidth and a clean radiation pattern, simplifying tuning with a relatively low SWR across the entire 20-meter band. Its robust performance makes it a practical choice for both fixed stations with limited tower space and portable _DXing_ operations. The design's characteristics are particularly beneficial for contesting and long-haul communications on 20 meters.

Constructing a high-gain, compact antenna for 2 meters often involves balancing theoretical performance with practical build challenges. WB8AHT recounts his journey in building a 6-element _Super Duper Moxon_ antenna for 144 MHz, inspired by designs from M0PXS and GW3YDX. He initially encountered discrepancies in published dimensions for the _HAARP Antenna_ and the _Super Moxon_, leading to on-air SWR issues and suboptimal performance. His methodical approach involved cross-referencing, direct communication with Phil Simpson (M0PXS), and iterative adjustments to element lengths based on observed results and a _SARK-110 Antenna Analyzer_ scan. After modifying the reflector/driven element and third director dimensions, the antenna achieved a respectable 1.35:1 SWR at 144.200 MHz. Field testing with 50 watts yielded contacts up to 500 miles, suggesting performance close to the 15 dBi gain predicted by _4NEC2_ software, despite its compact 40-inch boom. The article includes specific construction notes, such as tubing sizes (1/2-inch and 3/8-inch aluminum) and feedpoint spacing (50mm). The author's experience highlights the importance of real-world validation for antenna designs, even those with strong theoretical backing. He provides a table of tubing lengths for 6m, 4m, and 2m versions, along with his final, optimized dimensions, offering a practical blueprint for fellow hams interested in replicating or further experimenting with this high-performance, small-footprint VHF antenna.

Details the construction of a **17-meter Moxon Rectangle** antenna, specifically engineered for mounting on a mast beneath an existing beam. The design incorporates insulated wire calculations (0.95804 x generator length) to compensate for velocity factor differences, utilizing readily available materials such as crappie poles for elements, PVC for the boom and mast, and a Budwig HQ-1 dipole connector for the 50 Ohm coax feed. The project outlines a step-by-step assembly process, including mast construction from PVC T-connectors and pipe, element fabrication from crappie poles, and securing elements to prevent droop. Initial testing demonstrated an SWR of 1.3:1 on 17 meters, achieving a 5-8 signal report into Texas with 100 watts. Subsequent reinforcement and elevation of the antenna resulted in a 15 over 9 report from Florida. Comparative testing against an 88-foot center-fed Zepp antenna indicated superior performance, with the Moxon consistently outperforming the Zepp and receiving signals the Zepp could not. A notable DX contact with JA8NFV in Hokkaido, Japan, yielded a 5-9+ signal report both ways using 100 watts.