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This practical, hands-on article offers a valuable journey through balun construction for portable antenna systems. The author skillfully navigates from theoretical debates to practical implementation, providing a well-documented DIY process using RG316 micro coax and an FT114-43 toroid core. The step-by-step instructions, complemented by photographs, make this complex technical project accessible to hobbyists. Particularly impressive is the author's focus on lightweight design (just 173 grams) for SOTA field operations. While the final antenna requires minor tuning adjustments, the successful field test during the Pirate Contest demonstrates the effectiveness of this approach. An excellent resource that transforms theory into practical application for ham radio operators.

A QST Article published in November 1922 is about the origin of Beverage antennas, an unidirectional antenna type that was discovered and experimented for the first time in that period. This article is the introduction to beverage antenna theory, by the homonimous autho H. H. Beverage.

This article describes a multi-band antenna design for amateur radio enthusiasts by G3FEW. The antenna is designed to cover at least five HF bands with low SWR and without the need for an ATU. It is also designed to be easy to construct and adaptable for different locations. The antenna is a full-wave dipole with traps at the quarter-wave points. The traps are used to tune the antenna to different bands. The antenna can be fed with a 4:1 balun. The article includes instructions for building the antenna, as well as information on the theory behind its operation. The author also discusses the results of his tests with the antenna. This multi-band antenna is a well-designed and versatile antenna that can be used by amateur radio enthusiasts on a variety of bands. It is relatively easy to construct and can be adapted for different locations.

The Narrabeen JOTA and JOTI camp facilitates global communication for Sydney North Region Scouts and Northern Sydney Girl Guides, utilizing amateur radio and internet technologies. Participants engage in two-way radio contacts, often on **HF** bands, to connect with other scouting and guiding groups worldwide, fostering international goodwill and technical skill development. The event integrates both traditional **ham radio** operations and modern internet-based communication methods, providing a diverse experience for youth members. The resource outlines the specific activities undertaken at the Narrabeen site, including station setup, operating procedures, and the use of digital modes for JOTI. It highlights the educational aspects of the event, such as learning about radio propagation, antenna theory, and basic electronics, all within a structured camp environment. The page also provides logistical information relevant to the Australian context of the event.

Learn about the practical design and construction of Yagi antennas for ham radio operators. This post explores the benefits of Yagi antennas in receiving and transmitting RF signals, concentrating signal energy in one direction for long-distance communication. Discover the theory behind Yagi antennae, the importance of element size and spacing, and the resources available for sizing and construction. Whether you're interested in OTA television or amateur radio communication, understanding Yagi antenna design can enhance your signal reception and transmission capabilities.

A 5/8-wavelength vertical antenna offers a lower angle of radiation compared to a 1/4-wavelength vertical, which is crucial for maximizing DX contacts. This design achieves its optimal radiation pattern by effectively compressing the main lobe closer to the horizon, resulting in a more efficient signal path for long-distance communication. The article details how the current distribution along the antenna element influences the radiation pattern, illustrating why a 5/8-wave radiator typically exhibits a gain of approximately **3 dB** over a 1/4-wave vertical when both are operating over a perfect ground plane. Understanding the _radiation pattern_ and current distribution is key to selecting the appropriate vertical antenna for specific operating goals. While a 1/4-wave vertical is simpler to implement and often used for local contacts, the 5/8-wave design is preferred by DXers seeking to exploit its lower take-off angle. The article also touches upon the practical considerations of feeding a 5/8-wave vertical, which typically requires a matching network to transform its inherent reactive impedance to a standard 50-ohm feedline impedance. This technical explanation clarifies the performance differences.

Helical antenna or helix antenna is the antenna in which the conducting wire is wound in helical shape and connected to the ground plate with a feeder line. It is the simplest antenna, which provides circularly polarized waves.

This tutorial introduces and explains Smith Charts, and then gives an introduction to impedance matching. Smith Chart is a tool to visualize the impedance of a transmission line and antenna system as a function of frequency.

This PDF document provides detailed information on the design, construction, and tuning of trapped vertical antennas with radials for ham radio operators. It covers the theory behind trapped antennas, practical considerations for installation, and tips for optimizing performance. Whether you are a beginner looking to build your first HF antenna or an experienced operator seeking to improve your station setup, this guide offers valuable insights and instructions. By understanding the principles outlined in this document, hams can enhance their operating experience and make the most of their radio communication capabilities.

Presents the digital edition of "The Communicator," a journal from Surrey Amateur Radio Communications (SARC), offering a curated collection of articles, technical deep dives, and operational reports. Each issue, such as the July-August 2026 edition, details specific **homebrew projects** like an NTP Dual Clock, a True RMS to DC Converter, and an Arduino NANO automation mod for the Yaesu FH-2. It also covers historical accounts, including the legacy of SSB pioneer Nicolaas Kooman and the mystery of the Lagercrantz suitcase radio, alongside practical operating advice and contest summaries like Field Day 2026 and the RAC Canada Day contest. The journal consistently features diverse content, from exploring the capabilities of modern transceivers like the Icom IC-9700 for digital modes to discussions on antenna theory, such as building a vertical HF antenna without radials. It also addresses contemporary issues, exemplified by an article unpacking the FAA's "CW interference" directive concerning Boeing 787 transponders, clarifying that the interference is not related to amateur radio Morse code but rather unmodulated carrier signals impacting aviation frequencies around 1030 MHz and 1090 MHz. Furthermore, the publication includes lighter fare like "No-ham Recipes," club meeting minutes, and member profiles, providing a holistic view of the amateur radio community. It offers multiple access options for each issue, including full and lower-resolution PDF downloads, an online magazine reader, and an experimental AI-LLM audio podcast version, making its extensive content readily accessible to a global audience in over 165 countries.

A course on fractals antennas theory provided by La Ecole nationale superieure de techniques avancees in France. Course is in French.

A 5/8-wavelength vertical antenna for 2-meter FM operation is detailed, focusing on eliminating loading coils by utilizing a series inductor to cancel capacitive reactance at the feed point, thereby presenting a 50-ohm impedance match. The design illustrates three basic configurations, including a method employing a short-circuited coaxial stub for inductance, as implemented by K4LPQ. An alternative design is presented where the center conductor of the stub is extended one-quarter wavelength, creating a signal-frequency short and allowing for an insulated wire stub to develop the required series inductance. The article provides electrical theory and mechanical considerations for building the antenna, emphasizing the adjustment of stub length for proper impedance matching. This technical documentation is intended for amateur radio operators interested in homebrewing VHF antennas, offering practical insights into impedance matching techniques for vertical radiators.

DF6QV's 4-Square antenna analysis begins with a two-element array simulation, demonstrating azimuth and elevation plots for various phase differences, including a 75-135 degree range. The document then delves into the core components of a 4-Square system, such as radiators, couplers, phasing lines, and ground systems, referencing W1HKK's 1965 QST article on an 80m phased array. It explores the influence of ground conditions and element spacing on antenna performance, presenting EZNEC analysis for an 80m 4-Square with an elevated radial, showing how gain and beamwidth vary with spacing. Various 90-degree couplers, including the 3 dB hybrid coupler and the Reed Fisher coupler, are analyzed using LTSpice, detailing power splitting, phasing, and bandwidth characteristics. The resource quantifies power, voltage, current, and losses within a 4-Square system, addressing relays, capacitors, inductors, radiator radial systems, and cable losses. System impedance, bandwidth, SWR, isolation, and mutual coupling are discussed with practical construction aspects covering common mode chokes, phasing boxes, and remote control systems. Field test observations for 40m 4-Square antennas are included, with specific examples from DXpedition operations like 5A7A and VP6DX, providing real-world context to the theoretical and simulated results.

Testing of real antennas is fundamental to antenna theory. The most common and desired measurements are the antenna radiation pattern including antenna gain and efficiency, the impedance or VSWR, the bandwidth, and the polarization. The procedures and equipment used in antenna measurements are described in this page.