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

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

Operating a handheld transceiver (HT) while bicycle mobile presents a significant challenge due to the lack of an effective ground plane on a bicycle frame. This project addresses that issue by providing construction details for a 2-meter antenna, specifically adapting the _ARRL Hints and Kinks_ design by Charlie Lofgren, W6JJZ, known as the "Bike 'n Hike Special." The antenna is designed to function efficiently on the 144 MHz band, offering a practical solution for portable VHF communication. The design emphasizes simplicity and portability, crucial for mobile operations where space and weight are at a premium. It details the necessary components and assembly steps, allowing amateurs to build a functional antenna that overcomes the inherent limitations of a bicycle as a radio platform. The original concept was published in the ARRL's well-regarded collection of practical amateur radio solutions. This antenna project enables bicycle mobile operators to achieve improved signal performance compared to a stock HT rubber duck, facilitating more reliable contacts while on the move. It represents a straightforward approach to enhancing VHF communications for active hams who combine cycling with their radio hobby.

A 1/4 wavelength resonator design for dual-band VHF/UHF operation is presented, focusing on a robust mobile antenna construction. The design prioritizes stability against environmental influences over raw gain, making it suitable for general use rather than marginal signal areas. It details the antenna's two sections: a UHF-resonant lower conductor and an upper coil functioning as an RF choke for UHF and an inductance enhancer for VHF, forming a resonant circuit. Detailed mechanical structure and material considerations are provided, including the use of a PL-259 plug base, 2mm copper rod, and PVC faucet tube for the coil form. The guide outlines a precise construction procedure, from soldering the copper rod to the PL-259 to winding the 22 SWG laminated wire for the VHF section. Tuning involves careful cutting of the UHF section and adjusting the coil length and pitch for VHF, using a reflectometer and temporary ground planes. Furthermore, the resource describes converting the mobile antenna for base station application by constructing a dual-band ground plane system. This involves using electrical conduit, EMT connectors, SO-239 sockets, and a 4-inch round-pan with threaded stainless steel rods as ground elements. Practical test results indicate optimal lengths of **70mm** for UHF and **350mm** for VHF ground elements, with a recommendation to cut rods with _30mm_ extra length for fine-tuning.

A 9 dB gain 70cm collinear antenna construction is detailed, utilizing eight half-wavelength sections of _RG58/U_ coaxial cable. The design incorporates specific calculations for velocity factor (0.66 for RG58/U) to determine precise element lengths, such as 223mm for a half-wavelength at 444 MHz. A quarter-wave radiating element of #16 solid wire, 169mm long, is added to the top, and a 160mm aluminum tube acts as a quarter-wave counterpoise at the feed point. RF choke baluns, constructed from three _FT50-43_ toroids, are positioned a half-wavelength from the feed point to mitigate common mode current. Assembly involves soldering the coax sections in series, followed by SWR testing during construction and final mounting within a ¾-inch PVC pipe. The article suggests using four half-wave elements for a shorter antenna, noting a potential slight increase in SWR, which can be mitigated with quarter-wave ground radials. The design principles and formulas are scalable for other VHF/UHF bands like 6m, 2m, or 1¼m, providing a versatile homebrew solution for enhanced gain.

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.

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 self-supporting vertical antenna design for stationary-mobile HF-VHF operation is presented, emphasizing ease of construction with common materials like a fiberglass fishing rod and PVC pipe. The design focuses on creating a set of no-tuner monoband radiators for bands such as **2m**, **6m**, 10m, and 12m, with an overall radiator support length of 3.3m. The construction process details the assembly of the antenna base using a magnetic mount, PL-259 connector, and PVC pipe sections, which then supports the telescopic fishing rod. Radiator extensions are cut to achieve quarter-wave resonance on specific bands, with detailed instructions for 6m (50-51 MHz), 10m (28.5 MHz), and 12m (24.9 MHz). For lower HF bands like 15m, 17m, and 20m, the design incorporates base-loading coils, with specific turn counts provided (e.g., 21 turns for 20m). The project also suggests using an _antenna analyzer_ for precise tuning of extensions and coils, moving beyond theoretical values to achieve optimal performance. The author, _IK1ZYW_, notes that for 80m and 160m, the antenna becomes less efficient as a vertical, suggesting alternative configurations like an inverted-V dipole or asymmetrical inverted-L.

Normal mode helix antennas offer a solution for HF mobile operators facing significant height restrictions, such as those parking in indoor garages with limited overhead clearance. This design, adapted from concepts typically applied to VHF/UHF rubber duck antennas, allows for extremely shortened HF radiators that remain effective for county hunting and general mobile operation. The resource details the construction of a 20-meter helix antenna, approximately 10 inches long, wound with #14 AWG THHN wire on a 1 1/2-inch CPVC form, mounted on a standard 3/8 x 24 antenna stud. Mark Herson, _N2MH_, shares his experience developing these antennas, including initial research from the _RSGB VHF UHF Manual_ and practical winding experiments to establish the relationship between turns and resonant frequency. He provides coil data for various frequencies, emphasizing that these measurements were taken with an _MFJ-259a_ antenna analyzer and are dependent on the vehicle's grounding system. Despite their shortened nature, N2MH confirms the antennas' operational effectiveness, citing contacts with KL1V in Alaska on 20 meters and E-skip contacts on 10 meters. The design prioritizes continuous deployment without removal, making it suitable for operators who frequently navigate height-restricted environments.

Demonstrates adapting the _Moxon rectangle_ antenna design for 2-meter VHF operation, highlighting its unique characteristics for specific applications. It details how the antenna's small size and distinctive far-field pattern, typically associated with HF, can be effectively utilized on VHF. The resource provides modeled dimensions for three different element diameters (1/4", 1/2", 1") and discusses the necessary adjustments to maintain optimal performance, such as gap spacing and element lengths, to achieve a 50-Ohm feedpoint impedance. The article presents predicted performance data, including gain (dBi), front-to-back ratio (dB), and feedpoint impedance (R, jX) across 144, 146, and 148 MHz. It analyzes free-space azimuth patterns and discusses the antenna's behavior when horizontally and vertically polarized over ground, including its suitability for fixed installations, repeater applications, and even satellite communications. Construction considerations, such as bending elements and maintaining critical gap distances, are also addressed. Furthermore, the content explores advanced configurations like using two back-to-back rectangles for broader coverage and a crossed-Moxon setup for circular polarization, suggesting potential for urban communication and satellite work. The author, _L. B. Cebik, W4RNL_, emphasizes the Moxon's strengths in broad bandwidth, wide beamwidth, and high front-to-back ratio, rather than maximum gain.

A 144 MHz kilowatt amplifier project details the construction and performance of a high-power VHF linear using the GU74b tetrode. This Russian tube, equivalent to the Svetlana 4CX800, is noted for its conservative datasheet ratings, performing closer to 800-1000W anode dissipation in practical applications. The design prioritizes compactness and achieves 1.2 kW output with only 20W of drive power, demonstrating a 70% efficiency at 2.5 kV plate voltage. The amplifier has been successfully deployed in demanding _EME_ (Earth-Moon-Earth) operations since June 1994. Challenges encountered during development included achieving stability with a grid-1 input configuration. The author, _CT1DMK_, opted not to publish the full design due to its complexity, suggesting it might be difficult for less experienced builders to replicate successfully. However, he invites direct contact for those with specific interest in the design. Future plans include a "144MHz GS35b compact amplifier" project, promising another kilowatt-plus design. This resource offers insights into high-power VHF amplifier construction and the practical application of specific power tubes.

2m SSB/CW-12.5 Ohm Yagis with extrem high gain and small bandwidth. These Yagis were constructed as ultra-light, portable Yagis with extrem high gain. They have small bandwidth and are working from 144,0-144,8MHz with good SWR.

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.

The document is a PDF detailing the construction of the DBJ-1 VHF-UHF Dual Band J-Pole antenna for amateur radio use. It provides instructions on how to build a high-performance dual band base antenna for VHF and UHF bands using a single feed line for less than $10.

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.

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.

Demonstrates the construction of a **homebrew spectrum analyzer** designed by Wes Hayward, W7ZOI, and Terry White, K7TAU, enabling radio amateurs to build a capable test instrument without significant expense. The resource details a _double-conversion superheterodyne_ circuit, employing intermediate frequencies of 110 MHz and 10 MHz, and covers essential blocks such as the time base, logarithmic amplifier, resolution filters, and local oscillators. It highlights the use of hybrid and monolithic ICs, including mixers, amplifiers, and VCOs, to simplify construction while maintaining performance. The design supports useful measurements in the 50 kHz to 70 MHz range, with methods outlined for extending capabilities into VHF and UHF. The authors emphasize that this analyzer, while simple to build, is intended for serious measurements, requiring careful control of signal levels to avoid spurious responses. It uses an oscilloscope for display, with specific instructions for calibration and adjustment of various stages, including the log amplifier and IF gain. The guide provides detailed schematics and component lists for each section, such as the 110 MHz triple-tuned band-pass filter, which achieved **90 dB** image rejection, a significant improvement over double-tuned circuits. Practical advice on alignment and troubleshooting is included, drawing on the authors' extensive experience in RF circuit design.

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.

Communication Concepts, Inc. specializes in providing RF components for both amateur radio operators building their own gear and professionals prototyping circuit designs. The inventory includes a range of products such as HF and VHF amplifiers, splitter combiners, and various filters, catering to diverse applications from QRP to high-power systems. The site details specific components like _Freescale_ and _Motorola_ RF transistors, along with custom semi-rigid coaxial cable options. The offerings extend to parts for ATV, packet radio, and general electronic components, emphasizing quality and service since 1979. Customers can find items like low-pass filters for RFI/TVI mitigation and specialized transformers for RF power systems, covering frequencies from 2-30 MHz Type "H" to 1-80 MHz high-power applications. The resource highlights its role as a supplier for those constructing custom radio equipment, offering components that facilitate projects from basic radio kits to advanced amplifier designs, with a focus on enabling self-construction and cost-effective prototyping.

This resource details the construction of a versatile CW/QRSS beacon, designed around a Microchip _PIC16F84_ microcontroller. The project provides a flexible platform for transmitting either standard CW or very slow QRSS signals, making it suitable for LF, VHF, UHF, and SHF applications. It supports two distinct messages, each configurable for speed (from 0 to **127** WPM for CW, or up to **127** seconds per dot for QRSS) and repetition within a six-phase sequence. The core functionality relies on the PIC's EEPROM, which stores all operational parameters, including message content, transmission speeds, phase configurations, and relay control settings. This design allows for parameter modification directly via programming software like _ICProg_ without altering the main program code. The project includes a detailed schematic, a component list, and an explanation of the EEPROM memory mapping for messages, speeds, phase settings, and inter-phase delays. General-purpose outputs (OUT1, OUT2, OUT3) provide dry relay contacts for external control, enabling functions such as power switching, antenna selection, or frequency changes. A 'TRIGGER' input facilitates controlled starts or continuous free-run operation. Sample EEPROM configurations illustrate how to program specific beacon sequences, including message content and relay states.

Compiling an extensive collection of technical information, the Repeater Builder's website serves as a critical resource for those involved in amateur and commercial repeater systems. It covers a broad spectrum of topics essential for the design, construction, and ongoing maintenance of these vital communication hubs, drawing from years of practical experience in the field. The site provides detailed insights into various aspects of repeater technology, including specific information on VHF and UHF bands, such as 2-meter systems. Users can find data related to repeater logic, control systems, and interfacing with other radio infrastructure, all presented with a focus on practical application. Authored by Kevin Custer, W3KKC, the content reflects a deep understanding of repeater operations and engineering, offering guidance that extends beyond basic setup to advanced troubleshooting and optimization.

Demonstrates the iterative design and construction of a **tapped HF/VHF mobile vertical antenna** by K0EMT, detailing four generations of development. The antenna supports operation on 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, and 2m bands. Initial designs, like Generation 1, featured a 3/8" x 24TPI bolt in a PVC end cap with a 1" aluminum tubing mast, resulting in a 9'9" overall length and resonance around 6.9 MHz with the full coil. Subsequent generations refined the mast and coil forms, transitioning from aluminum to copper tubing (Generation 3, found too weak) and eventually fiberglass for the coil form (Generation 4, in progress). Coil tapping points were adjusted to achieve resonance without an external tuner in Generation 2. The project outlines material costs, totaling approximately $25, and mentions a successful 28 MHz QSO with EA3XA using an ICOM IC-706 mk II at 100 Watts. For 80m operation, an external wire with the maximum coil setting is used, or a 56" extender below the coil for stationary use.

Presents the detailed construction of the _FLA25HV_ antenna, a specialized array optimized for Earth-Moon-Earth (EME) communications on the 2-meter band. This resource provides schematics and practical insights into building a high-gain antenna system capable of reflecting signals off the lunar surface, a challenging but rewarding aspect of amateur radio. It covers the mechanical and electrical considerations essential for achieving the precise pointing and signal strength required for successful moonbounce contacts, often yielding **20 dB** or more gain. Amateur radio operators pursuing EME operations require robust antenna systems and precise tracking capabilities. The FLA25HV design addresses these needs by focusing on element spacing, impedance matching, and structural integrity to withstand environmental factors while maintaining critical alignment for lunar reflections. Such systems are crucial for making contacts over distances exceeding **768,000 km**. This personal page serves as a practical guide for hams interested in constructing their own EME arrays, offering a glimpse into the technical dedication involved in pushing the boundaries of VHF/UHF propagation.

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.

Presents the construction and performance characteristics of a **2-meter vertical Moxon** antenna designed by WB5CXC. The antenna utilizes 1/2-inch PVC and #6 copper ground wire for its physical structure. Performance data includes measured front-to-back ratio using a local repeater, demonstrating significant signal attenuation when rotated. The resource provides **antenna pattern** plots, with blue tracing the design at 146 MHz and red indicating performance at 148 MHz. Gain and SWR plots are also included, alongside a detailed diagram of the antenna's physical layout. The design emphasizes a good front-to-back ratio, aligning with modeling predictions.

A _Topfkreis_ antenna, also known as a "bicycle pump" antenna, is presented as a simple vertical design for the 70 cm band. This variant of the J-pole antenna is notable for not requiring a ground plane, simplifying deployment. The construction details specify using aluminum tubing for the radiating element, with precise measurements for the quarter-wavelength outer tube (32 mm diameter) and the three-quarter wavelength inner sliding tubes (10 mm and 8 mm). Feeding is via a 50-ohm coaxial cable connected 90 mm from the base of the central tube. This design can achieve a gain of **4 to 6 dB** when properly tuned using the adjustable radiating element. The article details the fabrication of a critical aluminum washer, suggesting a method using a hole saw and a drill press as a lathe for precise adjustment. The illustrated example is specifically for the 70-centimeter band, and the author, Pop, clarifies construction points in the comments, including material choices and assembly techniques, ensuring a robust build for VHF/UHF operation.

The PDF document, titled "J-Poles," presents various J-pole antenna designs covering the 50 MHz to 450 MHz frequency range. It includes construction details for several specific bands, such as a 6-meter J-pole, a 2-meter J-pole, and a 70-centimeter J-pole. The content outlines the fundamental principles of J-pole operation, including the quarter-wave radiator and half-wave matching stub. Each design features specific dimensions for elements like the radiator length, stub length, and spacing, often expressed in inches. The document also discusses feeding arrangements and impedance matching considerations inherent to J-pole antennas. It provides practical guidance for homebrewing these antennas using common materials like copper pipe or wire elements. The resource offers insights into the advantages of J-poles, such as their omnidirectional pattern and ease of construction, making it a practical reference for radio amateurs interested in VHF/UHF antenna projects.

The resource details the construction of a 6-meter _Moxon_ antenna, presenting two distinct versions: one horizontally polarized for 50-51 MHz CW/SSB and another vertically polarized for 52-54 MHz FM. It specifies the use of 5/8 inch OD and 1/2 inch OD aluminum tubing, with 3/8 inch OD solid aluminum for corners, and provides a comprehensive material cutting schedule. The design aims for robust, portable construction, with all materials costing under $100. Detailed drawings and EZNEC models are referenced for precise dimensions and assembly, ensuring accurate element spacing and impedance matching. The EZNEC model for the H-POL version predicts a gain of **11 dBi** and a front-to-back ratio of **25 dB** at 50.5 MHz, while the V-POL version shows a gain of **6.7 dBi** and a front-to-back ratio of **36 dB** at 53 MHz. The article includes practical SWR measurement advice, noting the impact of coax length and loss on analyzer readings. Field tests during a tropical storm demonstrated the antenna's durability and performance, yielding numerous contacts across significant distances, including California, Colorado, and Texas, on SSB and PSK.

A 2m Moxon antenna project, designed for the 145 MHz amateur radio band, provides a compact, directional solution for VHF communications. This resource details the construction process, specifying materials like PVC pipe for the frame, copper wire for elements, and a SO-239 connector for the feedpoint. The design emphasizes ease of build for hams seeking a gain antenna with good front-to-back ratio for local ragchewing or contesting. The project outlines precise element lengths and spacing, crucial for achieving the desired impedance and radiation pattern. It includes a visual representation of the antenna's dimensions and assembly, allowing for straightforward replication. The Moxon's inherent characteristics offer a practical alternative to larger Yagi arrays, particularly for portable operations or restricted spaces, while still delivering effective directivity and gain.

The **2M Moxon antenna** design presented operates at 144 MHz, providing a compact, directional solution for VHF communications. Construction involves aluminum tubing for the elements, with specific dimensions for the driven element and reflector to achieve optimal performance. The design aims for a good front-to-back ratio and a relatively low SWR across the 2-meter band, making it suitable for portable or fixed station use where directivity is beneficial. Element lengths are critical for proper resonance and pattern. The driven element measures approximately 38.5 inches, while the reflector is slightly longer at 40.5 inches. Spacing between the elements is 12 inches, forming the characteristic Moxon rectangle. This configuration yields a gain of about 5.5 dBi and a front-to-back ratio exceeding 20 dB, which is advantageous for reducing interference from unwanted directions. Feedpoint impedance is close to 50 ohms, allowing direct connection to coaxial cable without complex matching networks. The antenna's lightweight structure, typically under 2 pounds, facilitates easy deployment and rotation, making it a practical choice for field operations or as a compact home station antenna.

Demonstrates the design principles and performance characteristics of **corner reflector antennas**, emphasizing their high gain and directional properties. It covers critical design factors such as the corner angle and the spacing between the radiating dipole and the reflector vertex. The resource explains how reducing the corner angle increases gain but lowers feed impedance, making matching more challenging. Practical angles of 90 degrees or 60 degrees are discussed, with 90 degrees offering easier impedance matching despite slightly lower gain. Details key design considerations, including reflector side length exceeding two wavelengths and reflector width greater than one wavelength for a half-wave radiator. It specifies reflector construction using wire netting, sheet metal, or parallel metal spines spaced less than 0.1 wavelength. The article provides a table with general dimensions for UHF and VHF bands, noting typical impedance values of 50 to 75 ohms and expected SWR of 1.7:1 on the lower band edge. Adjustable radiator-to-vertex spacing is highlighted as crucial for final tuning.

The Construction Principles for Duoband-Yagis 2m/70cm by DK7ZB

This document contains the detailed instructions to build a homemade lindenblad antenna using a twin-lead as dipole elements. This document contains 9 pages and includes a detailed construction sequence and some drawings to build this antenna for UHF and VHF ham radio bands

The GW3YDX Super Moxon antenna design improves upon the standard Moxon Rectangle by incorporating additional directors in a rectangular configuration, yielding enhanced directivity and gain. For the 6m version, modeling with 4NEC2 and EZNEC+ indicated a 3dB gain increase and a 26.5dB front-to-back ratio, with VSWR below 1.5:1 between 50.0 and 50.3MHz when optimized for 50.1MHz. This design achieves a narrower -3dB power point beamwidth of 60° compared to the original Moxon's 80°, contributing to better QRM rejection. The boom length for the enhanced design is just under 2m, approximately double the original Moxon's, with no increase in wingspan. Construction details include tubing lengths for 6m, 4m, and 2m versions, with specific dimensions provided for elements A through M, measured to tubing centers. For instance, the 6m version uses a 2160mm element A and a 2140mm element H. The design maintains a 50-ohm feed impedance, with practical models showing VSWR plots consistent with simulations after minor adjustments to driven element lengths. The article also references Moxgen software for initial Moxon parameter calculation and NEC/EZNEC model generation. The 2m Super Moxon version measures approximately 30" x 25", demonstrating the compact nature of the design across different VHF bands. The article highlights the antenna's performance in real-world DX contacts on 6m, achieving contacts with over 80 stations in the USA from a modest QTH.

Demonstrates the construction of a 144 MHz turnstile antenna, detailing its design for omnidirectional, horizontally polarized VHF operation. The resource outlines the physical dimensions and materials required, including specific lengths for the radiating elements and the use of _RG-58_ coaxial cable for phasing. It covers the assembly process, emphasizing the critical spacing and connection points to achieve the desired radiation pattern and impedance matching for the _2-meter band_. The article presents measured _SWR_ performance across the 144-146 MHz segment, showing a low SWR of 1.2:1 at 144.5 MHz, which is suitable for general VHF use. It compares the turnstile's performance to a 9-element Yagi, noting the turnstile's advantage in providing consistent signal strength from all directions without requiring a rotator. Practical application for local FM simplex and repeater operations is implied, offering a simple yet effective antenna solution for fixed or portable stations.

The resource presents a detailed schematic for constructing a dual-band vertical antenna, specifically designed for operation on the 2-meter and 70-centimeter amateur radio bands. It illustrates the physical layout, critical dimensions, and component placement necessary for successful replication. Key elements such as the radiating elements, phasing sections, and feed point are clearly depicted, providing a visual guide for radio amateurs undertaking a homebrew antenna project. The diagram specifies the lengths for the VHF and UHF sections, indicating how these elements are integrated to achieve dual-band functionality from a single coaxial feedline. It also implies the use of common materials readily available to most experimenters, focusing on simplicity and effectiveness in its design. The visual format of a GIF image ensures direct access to the construction details without requiring extensive textual interpretation. This schematic serves as a practical reference for hams interested in building a compact, efficient vertical antenna for local and regional FM communications, offering a proven design for immediate implementation.

A 2-meter Moxon beam antenna, designed for the _144 MHz_ band, is detailed, originating from a desire to participate in the PW 2m QRP contest. The design, based on a Moxon Rectangle, offers a compact directional solution for VHF portable operations. The author, G0KYA, constructed the antenna using readily available materials like 15mm plastic conduit for the frame and 1.5mm copper wire for the elements. Initial testing with an MFJ-259B antenna analyzer showed a **1.2:1 SWR** at 144.300 MHz, indicating good resonance. The antenna's compact size, approximately 70cm x 40cm, makes it highly suitable for portable QRP work, providing a significant advantage over an omnidirectional vertical. The project includes practical advice on element spacing and construction techniques, emphasizing ease of assembly for field deployment. Field results from a local hilltop demonstrated the Moxon's directional characteristics, allowing for effective nulling of local noise and improved signal reception from specific directions.

A 6 dB gain Moxon rectangle antenna, designed for the 2-meter band, offers an excellent solution for hams seeking a compact, directional antenna for **SSB** operation, particularly in restricted spaces like an attic. This design emphasizes ease of construction using readily available materials such as 4mm OD brass tubing and plywood, making it an accessible project for many radio amateurs. The antenna's inherent characteristics, including a high front-to-back ratio of 37 dB and a 50-ohm feed impedance, contribute to its effectiveness in mitigating local noise and focusing radiated power. The project leverages the free MoxGen program for precise dimension calculations based on the desired frequency and wire size, and utilizes 4nec2 for pattern analysis, confirming a 3 dB beamwidth of 80 degrees. Construction involves bending brass tubing for the driven and passive elements, mounting them on an 800 x 350 mm plywood boom, and securing them with cable clips and epoxy resin. Initial SWR measurements at 144.3 MHz showed 1.6:1, which improved to 1.3:1 at 145.3 MHz across a flat band from 144.1 MHz to 145.5 MHz after adding a **coaxial choke** to mitigate common mode current.

This project details the construction of a **full-sized 40-meter vertical antenna**, born from a renewed interest in 7 MHz operation and a desire for improved effectiveness over simple dipoles. The author, K5DKZ, initially focused on VHF experimentation, which provided an inventory of aluminum tubing and fiberglass spreaders for this endeavor. Before this vertical, K5DKZ utilized an 80/40 meter inverted-vee trap dipole and a 40-meter broadband dipole, but now primarily uses a pair of full-sized, phased, quarter-wave verticals spaced 35 feet apart for serious 40-meter work. The construction involves a base-heavy design for stability, using a 44.5-inch section of 1-1/4 inch steel TV mast driven into 1-3/8 inch aluminum tubing, insulated by a 105-inch section of Schedule 40 PVC pipe. The assembly reaches 31 feet, close to the 32 feet required for a quarter-wavelength on 40 meters, with fine-tuning achieved by winding wire onto a fiberglass spreader. The design is explicitly presented as a foundation for a two-element 40-meter Yagi beam, outlining modifications like substituting aluminum for steel in the base and using an inductive hairpin match for the driven element. The article also discusses tuning considerations for a large 40-meter beam, noting the 100 to 200 kHz upward frequency shift when raised, and suggesting methods for installation on a tower. The author emphasizes the cost-effectiveness and good performance of the monopole approach, especially when multiple verticals are needed.

Article by VU2GT about VHF antennas, how to evaluate performances and models.

Examining the _Angle of Radiation_ and its impact on amateur radio operations, the resource provides insights into optimizing antenna performance for DX and local contacts. It features a design for SPOTTO, a direct conversion high-performance universal DSB transceiver, detailing its construction and operational characteristics for homebrew enthusiasts. Additionally, the site presents a 7-element VHF high-gain antenna design, offering practical schematics and expected performance metrics for those seeking enhanced gain on VHF bands. The resource also covers the development and popularity of the _FT8_ digital mode, highlighting its effectiveness in weak-signal conditions and its role in special event operations like the FT8DMC anniversary. It includes information on Hamfest India 2023 and the Lamakaan Amateur Radio Convention, providing dates and organizational details for significant Indian amateur radio gatherings. Technical articles on Direct Digital Synthesizers (DDS) VFOs and low-cost multifunctional frequency counters offer practical project ideas for radio amateurs.

The **KC0KJF** personal amateur radio page provides a collection of resources for fellow hams, particularly those interested in operations within southwest Missouri. It offers detailed listings for **Missouri repeaters** on both 2 meters and 70 centimeters, serving as a practical reference for local VHF/UHF communication. The site also includes information about the operator's station setup and antenna projects, such as a dipole and a bazooka antenna, which can offer insights into basic antenna construction and deployment. Beyond local repeater data, the page features links to the FCC Part 97 rules, essential for understanding amateur radio regulations. The operator, licensed as a Technician Class since April 16, 2001, shares his journey from Citizen's Band Radio to amateur radio, driven by a lifelong fascination with shortwave listening. This narrative provides context for the resource's focus on practical operating information and foundational regulatory knowledge. Additional content covers specific equipment like the 2-meter/70-centimeter Arrow Antenna, useful for hams considering portable or fixed station VHF/UHF setups.

Presents the construction of a 2-meter **Skeleton Slot Yagi** stack, detailing the design process and practical considerations for VHF operation. The author shares insights from building and testing this antenna, emphasizing its performance characteristics for local and extended range contacts. The project outlines the specific dimensions and materials used, providing a clear path for other radio amateurs to replicate or adapt the design for their own stations. The resource covers the unique aspects of the Skeleton Slot radiator, explaining how its geometry contributes to gain and pattern control. It includes discussions on impedance matching and feedline considerations crucial for optimizing power transfer and minimizing SWR. The article draws on real-world testing, offering practical results that validate the theoretical design. This project serves as a valuable reference for those interested in custom VHF antenna solutions.

An unconventional antenna family, the VHF/UHF Zigzag Dipole Antennas. Design, theory and practical construction, transformation and balancing with a half wave balun.

A 7 dB directional gain is reported for this portable VHF Yagi antenna design, which utilizes cut metal tape measure sections for its elements. The resource details the construction process for a 2-meter band antenna, emphasizing its ease of build and portability. It specifically mentions the design's suitability for radio direction finding (RDF), fox hunting, and communication with satellites and the International Space Station (ISS), highlighting its practical applications for amateur radio operators. The construction cost is estimated at under $20, with potential for even lower expense if salvaged materials like old tape measures and PVC pipes are used. The article references _Joe Leggio's_ (WB2HOL) original design, noting specific alterations made by the author. It also compares this design to other DIY Yagi antennas, including _FN64's_ 2-meter band and _manuka's_ 70-cm band tape measure Yagis, underscoring its unique combination of simplicity, portability, and effective performance with a 1:1 SWR achievable on the 2-meter band.

Documents the construction of a **VHF/UHF** antenna addition for the Buddipole HF antenna system, leveraging the existing Versa-Tee component. The project details the fabrication of a custom antenna mount from angle aluminum, including specific drilling and tapping for 3/16"-24 bolts, and the creation of radials from Simpson Strong Tie Insulation Supports. It specifies radial lengths for 70 centimeters (6 inches from the center stud) and 2 meters (19 1/4 inches), noting the use of wire nuts for safety. The resource outlines the construction of a mast from 1/2" ID PVC conduit, connected with 3/8"-24 connecting nuts and bolts, mirroring the Buddipole's modular design. It describes the integration of a mobile dual-band antenna with a 3/8"-24 mounting stud and the custom coax setup with BNC and **PL-259** connectors. Field testing with an FT-817ND and a separate dual-band SWR meter confirmed good SWR on both 2 meters and the 440-450 MHz section of 70 centimeters, with positive reception reports during Field Day activities. Further, the article describes the creation of a custom carrying solution, including a 22-inch tripod bag and a fabric roll-up, to emulate the portability of the original Buddipole system.

A 50.200 MHz Moxon antenna for the 6-meter band is detailed, providing practical construction guidance for amateur radio operators. The design utilizes 3/4" aluminum angle stock for the elements, joined with wood molding and 1/4 x 20 hardware. Key components include an SO-239 connector for the feedpoint and a **choke balun** made from coiled RG-58 coax, ensuring proper impedance matching and minimizing common mode current. The antenna measures approximately 29 inches deep by just under 7 feet long, making it suitable for portable operations. Specific dimensions, based on **Cebik's nomenclature**, are provided for the driven element and reflector. The resource also offers modeling hints, suggesting an effective element diameter of 1 inch for software simulations and emphasizing element sizing based on corner screws rather than end-to-end measurements.

Demonstrates the construction of a high-power 6-meter (50 MHz) amplifier, specifically designed for demanding modes like EME, TEP, and multiskip Es. It details the use of a _GU-43B_ tetrode in a grounded-cathode configuration, emphasizing the need for stabilized grid voltage and input capacitance compensation. The resource provides a comprehensive schematic, power supply design, and practical considerations for component sourcing, particularly for high-voltage and high-current sections. The builder achieved an output power of **1250 watts** with an anode current of 0.65 amperes and 3200 volts anode voltage. The article also covers the physical construction within a modified P6-31 enclosure, outlining the internal layout for RF and power supply sections, and includes photos of the completed unit. It highlights critical safety precautions for working with high voltages and reactive currents up to **20 Amperes** in the P-network.

Operating an amateur radio club, VE2CEV details its activities, including regular meetings and a significant project involving the construction of a **satellite ground station**. The resource outlines the project's inception, team formation, equipment acquisition, and the physical installation of antennas and rotator systems. It specifically mentions the use of a dual-axis AZ/EL rotator and antennas for VHF, UHF, and SHF (2 meters, 70 centimeters, and 13 centimeters), along with the strategic use of **Heliax cables** to minimize RF signal loss. The club also provides information on its interconnected repeater network covering southwestern Montérégie. The content highlights the practical application of the satellite station for communicating via amateur satellites and the International Space Station (ISS). It details the collaborative effort of members in securing a powerful Linux server, negotiating antenna installation with local authorities, and the precise alignment of antennas. The club emphasizes its role in guiding new amateurs, offering demonstrations, and potentially organizing courses, indicating a focus on community engagement and technical education within the amateur radio hobby.