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Designing a compact directional antenna for the 70cm band involves balancing gain, front-to-back ratio, and physical size. This resource details the construction of a 2-element Moxon rectangle antenna for 432 MHz, outlining the specific dimensions for the driven element and reflector, and discussing the advantages of its folded dipole configuration. The article provides insights into the historical context of 70cm operations and the author's personal experiences with early 432 MHz transceivers and antenna setups, such as a Jaybeam 48-element TV antenna. It also touches upon the practical aspects of building and deploying such an antenna for local and weak-signal work. The Moxon antenna design is compared to a 3-element Yagi, noting its superior front-to-back ratio and broader bandwidth for a given boom length, making it suitable for portable operations or restricted spaces. The construction uses readily available materials like copper wire and PVC tubing, emphasizing simplicity and ease of replication. Performance characteristics, including a reported gain of approximately 5.5 dBi and a front-to-back ratio of 20 dB, are discussed in the context of its compact footprint. The resource includes a visual representation of the antenna's dimensions and construction, aiding in practical implementation.

The Buddipole website showcases a range of portable amateur radio antenna systems, including the **Buddipole**, Mini-Buddipole, Buddistick PRO, and BuddiHEX, designed for rapid deployment and multi-band operation from 40 meters to 2 meters. Each product page details specifications, operational modes (dipole or vertical), and compatible accessories like tripods, masts, and baluns. The site also features portable DC power management systems such as the PowerMini 2 and PowerPlus, which include integrated battery chargers and solar controllers, catering to off-grid or field day setups. Instructional videos demonstrate antenna assembly, tuning, and deployment techniques for various configurations, including the VersaTee vertical and Mini-Buddipole. Customer testimonials and DXpedition highlights, such as operations from Montserrat (VP2M) and Dominica (J38), provide real-world examples of the equipment's performance in challenging environments. The company, established in 2001, emphasizes modularity, versatility, and efficiency in its product line, all manufactured in the USA. Shipping information, a 30-day return policy with no restocking fee, and contact details for their Heber City, Utah facility are clearly presented. The site serves as a direct sales portal, offering a comprehensive catalog of antennas, power solutions, and components for portable amateur radio enthusiasts.

The provided resource offers a downloadable ZIP archive, "6 meter moxon.zip," containing comprehensive design files for a **6-meter Moxon antenna**. Specifically, it includes antenna models in EZNEC format, allowing radio amateurs to simulate and analyze the antenna's performance characteristics. The archive also features detailed drawings, photographic documentation of the construction, and various plots illustrating the antenna's radiation patterns and impedance matching. Authored by Allen Baker, KG4JJH, the content focuses on a horizontally polarized Moxon antenna optimized for 50.5 MHz. The EZNEC files, such as "Moxon 6m 50.5 MHz H-POL.EZc," provide precise geometric and electrical parameters for replication or modification. The collection of files, totaling approximately 10 MB, serves as a practical guide for hams interested in building or understanding the design principles of a compact, directional 6-meter antenna, presenting both theoretical models and visual construction aids.

One of the best antenna values on the market is the LightningBolt Quad. At about half the cost of a tri-band yagi, you get five band coverage with a single coax feedline and excellent performance from a light, low wind load antenna.

5 Band 1/4 wave Telescopic Antenna. The 20m to 10m, antenna is simple and cheap to make, and has a performance that matches commercial antennas but at cost considerably lower. The design was purposely based on a telescoping fibre glass fishing rod as this allows it to be easily stowed away in the car.

Operating amateur radio satellites effectively requires precise knowledge of their orbital mechanics and pass times. Gpredict, a real-time satellite tracking and orbit prediction application, addresses this need by allowing operators to monitor numerous satellites simultaneously. It displays critical data such as position and pass details through various visualizations, including lists, tables, maps, and _polar plots_. Unlike many other satellite tracking programs, Gpredict introduces the concept of visualization modules. These modules enable users to group satellites and configure each group independently, offering unparalleled flexibility in how orbital data is presented. This modular approach supports tracking satellites from multiple observer locations concurrently, which is particularly useful for stations with diverse antenna setups or remote operations. Originally a GUI client for John Magliacane's _Predict_ program, Gpredict evolved to integrate its own tracking code for improved performance. The software is distributed under the GNU General Public License, ensuring it remains free and modifiable for the amateur radio community.

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.

The N0KHQ Coax Square antenna, designed for 17 meters and built using RG-58 coaxial cable, presents an intriguing option for hams with limited space. L. B. Cebik, _W4RNL_, meticulously models and analyzes this array, clarifying its classification not as a modified Moxon, but as a distinct member of the "dual-coupled, 2-element, parasitic array" family. The design leverages the velocity factor of RG-58 (approximately 0.66-0.67) to achieve significantly shorter element lengths compared to full-size counterparts, resulting in a perimeter of 42 feet for the N0KHQ array versus 54 feet for a standard Moxon. _NEC_ modeling reveals the coax square's performance characteristics, including a forward gain of 5.6 dBi and a 23.7 dB front-to-back ratio on 18.118 MHz. While slightly less gain than a Moxon (6.0 dBi), its pattern exhibits Yagi-like nulls at 90 degrees, distinguishing it from the Moxon's wider beamwidth. The article also delves into the unique feedpoint considerations, explaining how the split braid and center conductor of the RG-58 driver effectively form a folded dipole, allowing for impedance transformation to achieve a good match for 50-Ohm cable. Despite its shortened elements, which inherently narrow the operating bandwidth, the coax square maintains satisfactory performance across the 17-meter band. The analysis emphasizes that while SWR curves are important, a holistic view of gain and pattern degradation across the band is crucial. This antenna is a viable solution for operators needing a compact, directional array, particularly for narrow bands like 17, 30, or 12 meters, where its high-Q performance is most effective.

In 1999, W5GVE presented a detailed construction article for a 2-meter _DDRR_ antenna, specifically designed for mobile operation. This unique antenna, a Directional Discontinuity Ring Radiator, offers a compact footprint, making it suitable for vehicular mounting where traditional quarter-wave verticals might be impractical. The design emphasizes ease of homebrewing, utilizing readily available materials and basic workshop tools, allowing radio amateurs to build an effective mobile antenna for the 144 MHz band. The article provides insights into the antenna's performance characteristics, noting its low profile and potential for reduced wind loading compared to taller mobile whips. W5GVE's experience with the DDRR design suggests it can provide reliable communications on the 2-meter band, even in challenging mobile environments. The construction details include specific dimensions and assembly steps, guiding the builder through the process of creating a functional antenna. This project offers a practical alternative for hams seeking a discreet yet effective 2-meter mobile antenna, potentially achieving **3 dB** gain over a standard mobile whip.

Calculates precise dimensions for **Moxon rectangle** HF antennas, enabling hams to design antennas by inputting desired resonant frequency and wire diameter. This web-based tool, version 0.5, is a PHP front-end developed by W4/VP9KF, based on a public domain BASIC program originally authored by L. B. Cebik, W4RNL. It generates critical measurements for the driven element and reflector, ensuring proper spacing and element lengths for optimal performance. User feedback confirms the calculator's accuracy, with one user reporting resonance within 50 Hz of the design frequency for an 18 MHz antenna, eliminating the need for SWR adjustments. This contrasts with other online tools that resulted in significant frequency discrepancies. The tool's precision facilitates building **directional antennas** for specific bands, contributing to effective DXing and contesting operations.

The 6 Band Inverted L Antenna MK3 is a versatile multiband antenna designed for amateur radio operators. This antenna covers 160m, 80m, 40m, 20m, 15m, and 10m bands, making it suitable for a wide range of HF communications. The design is based on a W3DZZ configuration, incorporating traps for optimal performance. The MK3 version features a sturdy 5/8th CB mast, replacing the original timber mast, which enhances durability against harsh weather conditions. The antenna's construction allows for effective operation, particularly on the 40m band, where it has been successfully used to contact distant locations including ZL, VK, and Antarctica. Constructing this antenna requires careful attention to detail, especially regarding the radials and grounding. The traps resonate at specific frequencies, and additional resources are available for building coaxial traps. The antenna is designed to work efficiently without an ATU on the lower bands, while higher bands may require tuning. This project is ideal for both beginner and intermediate operators looking to enhance their station with a reliable multiband antenna.

Constructing a linear focus parabolic antenna for WiFi operation involves precise metalwork, as detailed in this project. The author, AB9IL, shares a build that can be completed in a few hours, emphasizing the hands-on process of shaping and assembling metal components. This design aims to provide enhanced signal range for 2.4 GHz wireless networks, a common challenge in many ham shacks and home setups. The project outlines the practical steps required, from initial measurements to the final assembly, including cutting, bending, and bolting various metal parts. While specific gain figures are not provided, the parabolic design inherently offers significant _directional gain_ compared to omnidirectional antennas, making it suitable for point-to-point links or extending network coverage over distances. The construction process focuses on readily available materials and basic shop tools, aligning with the DIY spirit prevalent in amateur radio. This antenna project is presented as a straightforward build, requiring attention to detail in fabrication to achieve optimal performance.

A multi band delta loop antenna that work on 20 and 40 meters band, that can be used either on 15 meters with poor performances

The document details the optimization and construction of the _Maria Maluca_ antenna, a compact 6-band (20m-6m) directional beam. It presents a comparative analysis of shortwave antenna principles, highlighting the efficiency gains achieved by using an open feeder line and tuner as a resonant unit, contrasting this with the losses associated with traps or capacitive loads in multiband antennas. The resource specifically revisits an older South American 2-element design for 10, 15, and 20 meters, applying modern NEC-based software to develop a six-band version. Performance data is meticulously tabulated, showing impedance, free space gain, gain at 12m height, elevation angle, and front-to-back (F/B) ratio for each band from 20m through 6m. For instance, on 15m, the antenna achieves 5.1 dBd free space gain and 13.72 dB F/B ratio. The construction section provides practical guidance on element assembly using aluminum pipes and hose clamps, detailing the use of a heavy-duty glass fiber reinforced polyamide rod for electrical separation and bending strength. It also specifies the use of 450-ohm _Wireman_ line CQ 552 for the transmission line. The document includes diagrams for rod fixing, an air-wound balun, and a vertical elevation diagram for the 15m band, illustrating its DX qualification. It also discusses the antenna's suitability for portable and expedition operations, noting its compact transport dimensions (max 1.50m length, 12 lb weight) and quick assembly time (under 15 minutes). The author, Dipl.Ing. Helmut Oeller, DC6NY, is identified as a source for material kits.

W1ZY's 40-meter **Moxon** antenna project details nine months of experimentation, culminating in a reversible array built from No. 12 insulated wire. The design incorporates two RF current baluns and a unique two-wire element construction, where each element consists of two parallel wires spaced 3 inches apart. The resource provides specific dimensions for the first prototype, including A=50.98', B=7.87', C=1.25', D=9.3', and E=18.42', optimized for 7.050 MHz CW operation. It thoroughly explains the construction of custom two-wire insulators from Plexiglas semi-rods and the critical pre-tensioning process required to maintain wire separation and array integrity. The author, Bill, emphasizes the antenna's exceptional receive performance, noting a 30-35 dB front-to-back ratio, which allows for significant signal rejection from the rear. While the Moxon offers 5-6 dB gain on transmit, its primary advantage lies in its ability to radically reduce rear-facing signals on receive, a characteristic Bill believes is often overlooked in transmit-focused comparisons. The guide details a flexible tuning method using removable tail-end jumpers, enabling adjustments to both tail-end and parallel dimensions without re-soldering the feed point, a technique refined over three prototypes.

Theory, Modeling, and Practical Applications By W5JCK, presentation in PDF File. This presentation focuses on Near-Vertical Incidence Skywave (NVIS) antennas, which are crucial for short-range radio communications, particularly in military and emergency contexts. It explores NVIS theory, antenna models, and installation criteria while debunking common myths about reflectors. Key topics include usable frequency bands, optimal installation heights, and the impact of soil quality on performance. The presentation outlines the best bands for daytime and nighttime use, emphasizing the importance of understanding propagation characteristics to enhance communication effectiveness within 200 to 300 miles.

For radio amateurs seeking compact, directional antenna solutions, the Moxon Rectangle offers an attractive alternative to traditional two-element Yagis. This resource compiles several articles by L. B. Cebik, W4RNL, exploring the **Moxon Rectangle** design, which provides gain comparable to a full-size two-element array but with a significantly improved **front-to-back ratio** and a direct 50-Ohm feedpoint match. The collection covers both wire arrays, particularly for lower HF bands, and rotatable aluminum beam constructions, addressing various aspects of this popular antenna configuration. The articles delve into specific band applications, including designs for 10 meters, 40 meters, and 2 meters, alongside discussions on multi-banding techniques and pattern characteristics. Comparisons are drawn between the Moxon and other antenna types, such as VK2ABQ Squares, highlighting the Moxon's advantages in terms of size and performance. Practical construction notes are provided for both wire and aluminum versions, offering insights into building these antennas for different operating environments.

The Double Bazooka Dipole is a half wave dipole with an attempt at compensation of the reactance change that occurs around resonance for a half wave dipole.

A quarter-wave vertical antenna design for HF operation offers a practical solution for radio amateurs seeking a compact and efficient multi-band radiator. This project details the construction of a 5-band HF vertical, drawing inspiration from established commercial products such as the _DX COMMANDER_ and the MV6. The design emphasizes ease of assembly and disassembly, making it suitable for portable operations or installations with limited space. The article provides insights into various construction methods and offers practical tips for building a robust yet lightweight antenna. It highlights the benefits of a vertical configuration for DX contacts, particularly on the lower HF bands, and discusses real-world performance observations. The antenna is designed to cover multiple HF bands, providing versatility for various operating scenarios. Operators can achieve significant DX results with this type of antenna, often comparable to more complex arrays, especially when deployed with an effective ground system. The project aims to empower hams to build a capable antenna without significant financial outlay.

A base station antenna you can easily build for 146,220 or 440 MHz, with performance similar to a J-pole but smaller and less obstrusive

There are lots of good designs for matching transformers for receiving antennas. Make it yourself it's cheap and easy, and very high performance. This is the design used in the TRX-9 transformers.

The 10-meter EH Antenna document details the construction and performance of a specific EH antenna design for the 10-meter band. It describes the integration of an L+L balanced matching network, a key component for impedance transformation, and highlights the addition of a tuned coaxial trap. This trap, consisting of 8 turns of RG58 coax wound around PVC tube and resonated at 29 MHz with a 10 pF capacitor, effectively inhibits common-mode current on the feeder, stabilizing antenna tuning. The resource presents a circuit diagram in Figure 1 and assembly details in Figure 2, illustrating the use of PVC plumbing tube as host material for dipole cylinders made from recycled aluminum tubing. It also explains the fabrication of capacitor stators and slider sections from thin aluminum tubing. The author, Lloyd Butler VK5BR, discusses initial challenges with feeder interaction and how the tuned trap resolved these issues, leading to stable tuning. Limited backyard tests indicate that the antenna, with the trap fitted close to the input connector, might exhibit similar field strength for both low and high angle transmission, suggesting a potential skewing of the signal. The document references previous articles by VK5BR in "Amateur Radio" for further operational details of the matching network and trap functionality.

The Charles Gizmotchy high performance horizontal and vertical beam antennas. Two, Six, Ten and eleven meters antennas

VE7CA experiments on 160 meters band antennas, looking for better performances on reception.

Constructing a Lindenblad antenna for 137MHz NOAA satellite reception involves specific design considerations for optimal performance. The resource details the use of 4mm galvanised steel fencing wire, 300-ohm television ribbon cable, and wood/plastic components for the antenna structure. Key dimensions for a 137.58MHz-resonant antenna are provided, derived from the ARRL Satellite Handbook, specifying s, l, w, and d as 42, 926, 893, and 654mm respectively. The antenna is designed for Right Hand Circularly Polarised (RHCP) signals, requiring the four folded dipole elements to be tilted clockwise by 30 degrees. A significant aspect covered is impedance matching between the antenna's 75-ohm impedance and a typical 50-ohm receiver input. A twelfth-wave matching transformer, constructed from 117mm sections of 50-ohm RG-58 and 75-ohm RG-59 coax with a 0.66 velocity factor, is described. The article also addresses coaxial cable and connector selection, recommending 75-ohm Type-N connectors for RG-6 cable in professional setups and F56/F59 connectors for general use, while strongly advising against PL-259/SO-259 connectors for VHF. Strategies for mitigating Radio Frequency Interference (RFI) are discussed, including antenna placement to shield from local TV transmitters and the use of commercial or DIY band-pass filters, such as cavity resonators or helical notch filters, along with ferrite chokes on coaxial cables. Antenna orientation is explored, noting the Lindenblad's 'cone of silence' directly overhead and its maximized sensitivity towards the horizon. An experimental vertical tilt of 90 degrees is presented as a method to improve overhead reception and reduce interference from strong horizontal signals, particularly relevant in high RFI environments like the Siding Spring Observatory site.

This resource details the computer-optimized design of the _ZS6BKW_ multiband dipole, an evolution of the classic _G5RV_ antenna. It begins by referencing the original 1958 RSGB Bulletin article by Louis Varney G5RV, explaining the operational principles of the G5RV's flat-top and open-wire feedline on 20m and 40m, noting its impedance transformation characteristics for valve amplifiers of that era. The article then transitions to the rationale for optimizing the design for contemporary solid-state transceivers requiring a 50 Ohm match. The core of the project involves using computer modeling to determine optimal lengths for the flat-top and matching section, aiming for a VSWR of less than 2:1 on multiple HF bands. It discusses the process of calculating feedpoint impedance based on antenna length and frequency, referencing professional literature from Professor R.W.P. King at Harvard University. The analysis also considers the characteristic impedance (Z(O)) of the open-wire line, identifying a broad peak of adequate values between 275 and 400 Ohms. Specific design parameters for the improved ZS6BKW are presented, including a shorter flat-top and a longer matching section compared to the original G5RV, with a velocity factor of 0.85 for the 300 Ohm tape. The article confirms acceptable matches on 7, 14, 18, 24, and 28 MHz bands when erected horizontally at 13m, and also discusses performance in an inverted-V configuration, noting frequency shifts. The author, Brian Austin ZS6BKW, emphasizes the antenna's suitability for modern 50 Ohm coaxial cable without a balun.

JJ0DRC's HF multi-band delta loop antenna project, initially conceived during the waning peak of Cycle 23, addresses the common challenge of achieving effective DX operation from a small residential lot in Japan. Dissatisfied with a ground plane antenna's performance in SSB pile-ups, the author sought a beam-like solution without a tower, drawing inspiration from a JJ1VKL article in CQ Ham Radio Sep. 2000. The antenna, constructed in October 2000, employs two 7.2-meter fishing rods (37% carbon fiber, reinforced with cyano-acrylate glue and aluminum tape) and 1mm enameled wire, fed by an Icom AH-4 external antenna tuner. While the exact beam pattern remains unmeasured, JJ0DRC observed a significantly higher callback rate compared to dipole antennas, particularly on higher bands. The system's circumference length of 15-20m is crucial for maintaining a good beam pattern across HF bands, though performance on lower bands like 80m, 40m, and 30m becomes less directional as the length deviates from a full wavelength. Ongoing maintenance addressed degradation issues, including aluminum tape cracking and wire breakage at connection points due to strong winds (often exceeding 10-15m/s in winter). The author reinforced rod connections with IRECTOR PIPE SYSTEM components and INSU-ROCK ties, and improved wire attachment methods using Cremona rope and epoxy bond to enhance durability.

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.

Presented here is a high-performance, circularly polarized omni-directional antenna that is easy to build, easy to tune, inexpensive, and will work all the mode J Low Earth Orbit (LEO) satellites

Presents a comprehensive guide for constructing a broadband Hex Beam antenna, a popular directional array for HF operation. This design offers a compact footprint and excellent gain characteristics, making it suitable for limited space installations while providing significant performance advantages over omnidirectional antennas. The resource details the specific dimensions for a five-band Hex Beam covering 20, 17, 15, 12, 10, and 6 meters, emphasizing the critical element spacing and wire lengths required for proper resonance and pattern. It outlines the construction of the center post, spreaders, and wire elements, along with the feed point assembly, ensuring proper impedance matching. The project aims for a forward gain of approximately **5.5 dBi** on most bands, with a front-to-back ratio often exceeding _20 dB_. Building this antenna requires careful measurement and assembly, but the resulting performance provides a substantial upgrade for DXing and contesting.

Engaging in **QRP** operations, where amateur radio transceivers transmit at five watts or less, presents a unique challenge and satisfaction for many radio amateurs. This mode emphasizes efficient antenna systems, keen operating skills, and often, the art of **homebrewing** equipment to maximize performance under power constraints. Operators frequently utilize CW (Morse code) for its superior signal-to-noise ratio, enabling reliable contacts over long distances with minimal power. The VK QRP Club, formally known as the CW Operators' QRP Club Inc., serves as a focal point for Australian amateurs passionate about these low-power pursuits. The club fosters a community where members can share insights on antenna design, circuit construction, and operating techniques specific to QRP. It provides resources such as information on club nets and frequencies, Morse practice materials, and a platform for exchanging ideas among enthusiasts. Membership offers access to a network of like-minded individuals, promoting the continued development and enjoyment of QRP within the amateur radio hobby. The club's activities encourage experimentation and skill refinement, vital aspects of successful low-power communication.

Illustrates the construction of a compact _Moxon_ beam antenna specifically tailored for the 40-meter band (7 MHz). The resource details a homebrew project by W7XA, emphasizing its design for limited space while maintaining good bandwidth and directivity characteristics. It highlights the practical application of the _Moxon_ rectangle model to achieve performance on a lower HF band. The primary content is a downloadable PDF document titled "40-Meter-Mini-MOXON-Beam-Antenna.pdf," which provides comprehensive illustrations and technical specifications for replicating the antenna. This includes dimensions, materials, and assembly instructions, making it a practical guide for radio amateurs interested in directional antennas for HF. The project demonstrates how a relatively small footprint can yield a directional antenna suitable for DXing or contesting on 40 meters, a band typically requiring much larger arrays for similar gain and front-to-back ratios. The documentation supports hands-on construction.

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.

D3+ High Performance Antennas for Field Day. This article describes versatile broadband wire antennas. These antennas will double your effective radiated power over a dipole, will be easy and inexpensive to build and install, and will be simple to match.

This is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It is a dipole fed off center with a 4:1 current balun at the offset feedpoint. The antenna shown covers 80, 40, 20 and 10 meters with 15 meters and WARC bands

The Q-signal **QRP** signifies a request to reduce power, and in amateur radio, it defines operating with 5 watts or less for CW and 10 watts or less for SSB. This article addresses common inquiries from new hams regarding the practice, its benefits, and implementation methods. It explains how a 5-watt QRP signal, compared to a 100-watt signal, typically results in only a 13dB drop in signal strength, equating to about two S-units, still providing solid copy under most conditions. Hams choose QRP for various reasons, including seeking a greater challenge in DXing or contesting, reducing band interference, or enabling portable field operations with lightweight, battery-efficient equipment. A modern single-band CW transceiver, key, and antenna can fit into a pocket, offering receiver performance comparable to commercial rigs and extended operation on a small battery. This portability facilitates operations in remote locations where higher-power setups are impractical. Operating QRP can involve simply reducing power on an existing commercial HF rig or building a dedicated QRP transceiver from a kit, such as the **Wilderness Radio SST** with its 2-watt output and 15mA receive current draw. While SSB is viable, CW remains the most popular and efficient mode for QRP due to its superior signal-to-noise ratio. The article lists common QRP calling frequencies across 160m through 10m bands for both CW and SSB, and highlights organizations like QRP ARCI and NorCal that support the QRP community.

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.

The ZS6BKW wire antenna, a variant of the G5RV, utilizes a specific 13m (42.6 ft) length of 450-ohm window line as its matching section, feeding a 28.5m (93.5 ft) flat-top element. This design aims for lower SWR on 40m, 20m, 17m, 12m, and 10m compared to a standard G5RV, often achieving SWR values below 1.5:1 on these bands without an antenna tuner. The feedpoint impedance transformation provided by the window line allows for direct connection to 50-ohm coax on multiple bands. F4FHH's experience involved constructing the ZS6BKW and evaluating its performance against an _OCF dipole_ (Off-Center Fed) on various HF frequencies. The article includes observations on SWR readings and operational effectiveness, highlighting the ZS6BKW's suitability for multi-band operation. The antenna's overall length, including the flat-top and window line, is approximately **41.5 meters** (136 feet), making it a significant wire antenna for fixed station use. Comparative analysis with the OCF dipole provided practical insights into the ZS6BKW's advantages and limitations, particularly concerning bandwidth and tuner requirements.

The simple dipole is perhaps the best antenna for consistent performance. Basic page on dipoles by G3PTO

Presents the Light Loop, a small magnetic loop antenna optimized for 40m through 10m operation, demonstrating its construction for portable QRP use. The design emphasizes lightweight materials and a compact form factor, making it suitable for handheld or backpack deployment during field activities. It details the primary radiating element, the coupling loop, and the variable capacitor required for resonance across the specified HF bands. The article provides specific component choices, such as the 1.5-inch diameter aluminum tubing for the main loop and the 10-365 pF variable capacitor for tuning. It discusses the importance of precise loop circumference and spacing for efficient impedance matching and bandwidth characteristics. The resource includes practical advice on achieving resonance and optimizing performance for low-power transceivers. Construction notes cover the mechanical assembly, including mounting the capacitor and feedpoint connections. It highlights the antenna's suitability for pedestrian mobile operations, offering a practical solution for HF communication without extensive setup. The design aims for a balance between portability and effective radiation on the lower HF bands.

The AMRAD Active LF Antenna. You can tune into LF activity with this easy-tobuild and erect active antenna. As a bonus, you get MF and HF coverage, to not to mention world-class performance

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.

The Grid Yagi (or Grid Quad) is a high performance yagi antenna that can be built with readily obtainable inexpensive materials. Described here is a 6 element 2 meter version with a boom length of about 1 wavelength, shown

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.

Demonstrates the construction of two distinct wideband RF preamplifiers, detailing their component requirements and performance characteristics. The first design leverages monolithic microwave integrated circuits (MMICs) such as the MAR-6, MAR-8, or PGA103, offering a broad frequency response from DC to 2 GHz with a gain of 22.5 dB at 100 MHz and a noise figure typically below 3 dB. This MMIC-based amplifier incorporates protection against power supply transients and features a 50 Ohm input/output impedance, operating from an 8-20 volt supply with low current drain. The second preamplifier design utilizes a BSX-20 transistor, providing amplification across the 14 MHz to 550 MHz range. This simpler, more economical build achieves an average gain of 12 dB at 145 MHz and a noise figure of approximately 1.1 dB. It operates from a 7-15 volt battery supply with a current draw of 6 mA. Both projects emphasize critical construction techniques, such as maintaining short RF connections, ensuring 50 Ohm impedance paths, and mounting the circuit within a shielded enclosure to optimize performance and minimize noise. The resource also discusses phantom power options for antenna-mounted preamplifiers and precautions for use with transceivers, including output protection diodes and static bleeders.

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.

A simple beam antenna offering good performances on 3 bands by 9m2mso

The QRP choke balun described utilizes a high permeability ferrite rod and RG-174 coax, aiming to present high impedance to common-mode currents across the HF spectrum. The construction involves winding as many turns of RG-174 as possible around the ferrite rod, then encapsulating the assembly with hot glue. This design prioritizes maximizing inductance to suppress unwanted shield currents, particularly in unbalanced antenna configurations. While the balun's effectiveness is subjectively reported as good, a potential design consideration involves the dielectric properties of the hot glue. This material could increase turn-to-turn capacitance, potentially reducing the balun's performance at higher HF frequencies, though this specific aspect has not been formally tested by the author, _AA5TB_. The project serves as an illustrative example of a practical, junk-box construction rather than a rigorously engineered solution. Photographs detail the evolution of the balun, from the initial winding process to its integration within a _B&W dipole center insulator_ and final camouflaged assembly.

A half-sized Hentenna designed for unique performance in compact spaces. Initially built in 2003 for monitoring a local 146.97 MHz repeater from a basement shop, the antenna proved highly effective, operating at just 200mW. In 2005, it was adapted for use in a challenging river-bottom location, delivering reliable performance on a 2-meter band with 5W. Despite its compact size, the Forktenna demonstrated excellent results compared to a full-sized Hentenna, making it an intriguing option for many hams.

The resource provides an in-depth analysis of the W6NL 40m _Moxon Yagi_ antenna, utilizing a NEC-2 model to simulate its performance. It details the antenna's design parameters, including element lengths and spacing, and explores critical operational aspects such as feedpoint impedance, SWR across the 40-meter band, and radiation patterns. The document systematically presents the model's setup and the methodology for evaluating the antenna's behavior in different environments, including free space and over real ground. Performance data derived from the NEC-2 model illustrates the antenna's forward gain, front-to-back ratio, and beamwidth. For instance, the model predicts a free-space gain of approximately **6.5 dBi** and a front-to-back ratio exceeding **20 dB** at resonance. Comparisons are drawn between free-space performance and operation at various heights above average ground, demonstrating the impact of ground proximity on take-off angle and overall efficiency. The analysis also touches upon the antenna's bandwidth characteristics, indicating its suitability for the entire 40-meter band with acceptable SWR.