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This resource details the fundamental aspects of deploying longwire antennas, emphasizing ease of construction and installation for shortwave listening (SWL) and broadcast reception. It covers wire gauge selection, suggesting 14 to 24 AWG for general use, with heavier gauges (14-20 AWG) for permanent outdoor installations. Guidance is provided for various deployment scenarios, including indoor setups where the wire can be run around a room, temporary outdoor installations from balconies using light 18-24 AWG wire, and permanent outdoor configurations requiring higher placement and slack for tree movement. Feeding methods are discussed, recommending coaxial cable (50-75 ohms) to mitigate man-made interference, with instructions for connecting only the center conductor to the longwire. Safety precautions are highlighted, particularly avoiding contact with power lines and conductive materials, and managing static electricity buildup by unplugging the antenna after use and bleeding off charges before connection. The article also advises against using outdoor longwires during thunderstorms or snowstorms due to static and lightning risks. Optimal height considerations are presented, advocating for the highest safe placement, ideally a couple of feet above underlying structures, to maintain free air space. The text mentions a personal setup with one end at a roof peak (20 feet) and the other at a 17-foot mast, illustrating practical deployment without strict height requirements beyond safety and clearance.

Basics by From Ian C. Purdie, VK2TIP

DIY Basic Electronic Theory, Basic Antenna Theory with Antennas built from common materials. What does SWR really mean. Baluns from transmission line.

Basic and illustrated article on building wire dipole antennas. This page is about "how to build a dipole antenna"

Article designed to answer basic questions about antennas

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

Slinky Antenna Basics, clandestine dipole

Basics and principles of the HB9CV antenna by Rudolf Baumgartner. This antenna join electric advantages of the two elements direct feeded aerials with the mechanical advantages of the Yagi antennas, in French.

An interesting article on NVIS antennas, explaining basics of NVIS antennas and the main usage of this particular aerials by Patricia Gibbons

A 2-meter Turnstile antenna, detailed for amateur satellite communication, offers a straightforward build for those looking to engage with orbiting transponders. The author, WB8ERJ, shares his personal design and construction methods, emphasizing the antenna's simplicity and effectiveness for LEO (Low Earth Orbit) satellite work. This design provides a circularly polarized signal, crucial for mitigating _Faraday rotation_ and signal fading often encountered with linearly polarized antennas when tracking satellites. Construction involves readily available materials like PVC pipe and copper wire, making it an accessible project for many hams. The article includes practical advice on element spacing and feed point considerations, drawing from the author's hands-on experience in the shack and field. It highlights the antenna's utility for receiving signals from various amateur satellites, including the popular AO-91 and AO-92. The Turnstile's inherent omnidirectional pattern in the horizontal plane, combined with its circular polarization, yields consistent signal reception, often resulting in **stronger decodes** and **more reliable contacts** compared to basic dipoles or verticals.

Design and optimize Yagi antennas. Ol GW Basic program for dos.

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

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.

Learn basic theory on antennas, and notes on homebrewing efficient shortwave antennas

A basic article on end-fed antennas by KB6NU

Designing **Moxon Rectangle** antennas often involves an urge among builders to find simple "magic formulas" for element lengths. L. B. Cebik, W4RNL, argues against this simplistic approach, emphasizing that antenna dimensions do not scale linearly and are influenced by factors like wire size and height above ground. This resource presents a procedure for developing sensible design equations, starting with uniform-diameter elements and perfectly conductive materials, with adjustments for real-world materials like copper and aluminum. The core of the method involves judicious **NEC modeling** (versions 2, 3, or 4) to create a baseline dataset for regression analysis, ensuring models meet specific performance standards for gain, front-to-back ratio, and feedpoint impedance. The derived equations, presented as a BASIC program, allow for calculating Moxon dimensions (A through E) based on wire diameter in wavelengths and design frequency. W4RNL demonstrates the efficacy of these equations by designing and testing Moxon Rectangles for 7.15 MHz (AWG #12 wire), 28.5 MHz (1" tubing), and 146 MHz (0.125" rod). Modeled performance data, including gain, front-to-back ratio, and feedpoint impedance, are provided for both perfect and real-world materials, showing high efficiency and close adherence to design goals. The article also references a standalone Windows program by AC6LA that automates these calculations and generates EZNEC or NEC models.

G3TXQ pages focuses on understanding the HexBeam antennas. Basics, dimensions, multi band issues, antenna modeling.

About HF Wire Antennas for field day or any day a basic wire antenna article

Basic information on the folded dipole antenna

Notes on Axial-Mode Helical Antennas in Amateur Service. Helix Basics, Modeling Issues, and Short Helical Antennas Over Perfect Ground

The G5RV multiband HF antenna, designed by Louis Varney (G5RV) in 1946, is a popular compromise antenna offering good overall performance on most HF bands when paired with an external antenna tuner. The basic full-size G5RV measures 102 feet across the top for 80 through 10 meter operation and is fed at the center via a 34-foot low-loss feed-stub. This interaction between the radiating section and the feed-stub facilitates matching across 80-10 meters with a standard tuner, often eliminating the need for ladder line directly to the shack. The antenna's design center frequency is 14.150 MHz, configured as a 3/2-wave dipole on 20 meters, with its 102-foot length derived from long-wire antenna formulas. Construction details emphasize the matching section, which can be open wire, ladder line (window-type), or TV twin lead. Each type has a specific velocity factor (VF) affecting its physical length for an electrical half-wave on 14 MHz; for instance, open wire requires 33.7 feet (VF 0.97), ladder line 31.3 feet (VF 0.90), and TV twin lead 28.5 feet (VF 0.82). The article provides formulas for calculating these lengths and discusses the antenna's behavior on individual bands, from 3.5 MHz where it acts as a shortened dipole, to 28 MHz where it functions as two three-half-wave long-wire antennas fed in-phase. Practical construction notes include recommendations for vertical descent of the matching section, sealing the coax junction, providing strain relief, and winding a coaxial choke coil to mitigate common mode current. The resource also presents dimensions for double-size (204 ft) and half-size (51 ft) G5RV versions, along with their corresponding matching section lengths for various line types, making it a versatile reference for hams considering this classic wire antenna.

Basic of shortwave antennas

A very basic guide to antennas concept. Explain the usage of dummy load, basic antennas like dipole o j-poles.

The basics of what is a discone antenna for wide band or bandwidth omnidirectional applications.

Experiments on HF antennas for restricted spaces. In this article author experiments antennas for 80-10 meters band having just a very small garden and several restrictions. Basic antennas consists of laded multiband dipoles and fan dipole antennas

Dish antenna and its theory and design for high performance applications such as satellite transmission and reception as well as microwave links. Parabolic Reflector Antenna: Dish Antenna The parabolic reflector antenna which is often called the dish antenna provides an antenna solution applicable for VHF and above where high gain and directivity are needed for all type of radio communications and radio reception.

Demonstrates various practical amateur radio projects and technical discussions through video episodes. One episode details cutting and retuning a _1/4 wave shorted stub_ from 101.7 MHz to 107.5 MHz to safeguard a transmitter's driver stage, alongside insights into advanced _160-meter antenna systems_ like eight-circle arrays and beverage antennas. Another segment covers upgrading firmware on an _ATS-20+_ receiver using AverDudes for improved display and functionality, and a detailed guide on using D-Star DR mode on an _ICOM ID-52A_ for international repeater programming. Additional content includes a deep dive into _OpenHamClock_ as a potential replacement for the HamClock project, updates on _Raspberry Pi 5_ running Trixie OS, and a review of the Choyong LC90 Internet radio with AI integration. The series also features "Ham College" episodes, which meticulously prepare viewers for the Technician Exam by covering topics such as antenna and transmission line measurements, SWR interpretation, and the functions of basic electronic components like rectifiers, relays, and transistors. Practical advice on coaxial cable characteristics, dummy loads, and proper soldering techniques is also provided.

Radio wave propagation, Principles of transmission lines, Antennas

Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.

About the basics of what is a discone antenna for wide band or bandwidth omnidirectional applications

About basics of the horn antenna used for many rf microwave antenna applications.

The 60-page PDF document, "Antenna Systems and Theory For The Non-Technical Ham" by Jim Abercrombie, N4JA, provides a foundational understanding of antenna systems. It explains basic antenna theory, including how antennas work, electromagnetic wave polarization, and the role of frequency. The resource details various antenna types such as flat top dipoles, inverted-V dipoles, shortened loaded dipoles, G5RV dipoles, Carolina Windoms, and end-fed configurations. Vertical antennas, including ground-mounted trapped verticals and inverted-L verticals, are also covered. Directional beam antennas like monoband Yagis, cubical quads, and log-periodic arrays are discussed. Propagation modes, including ground-wave, direct wave, and skywave propagation, are explained in detail, with specific attention to the D, E, and F layers of the ionosphere and their effects on HF communication. Technical concepts such as standing wave ratio, decibels, resistance, and reactance are defined, along with calculations for half-wave resonant dipole lengths. The document addresses feed-line radiation, balun applications, and critical antenna and tower safety considerations. It aims to dispel common antenna myths and educate hams on making informed antenna choices.

Effectively teaching amateur radio licensing classes requires more than just technical knowledge; it demands strong pedagogical skills and organizational acumen. This guide addresses the practical aspects of conducting successful amateur radio courses, emphasizing the instructor's role as an educational manager rather than merely a knowledge dispenser. It explores various class organizational structures, including traditional weekly sessions and _hybrid_ full-day formats, noting that many small meetings are often preferable for student engagement. The resource also provides strategies for finding suitable class locations, from public libraries and community centers to navigating public and private school systems, highlighting the importance of stressing the public service aspect of amateur radio to potential hosts. Key sections delve into effective classroom management, stressing the importance of preparation, a structured routine, and creating a comfortable learning environment. It details the VARK learning styles (Visual, Aural, Read/write, Kinesthetic), advocating for teaching methods that engage multiple senses to enhance student comprehension. The guide also offers advice on breaking down complex technical material, defining unfamiliar vocabulary, and making theoretical concepts practical through real-world examples. It includes a sample entry-level license syllabus covering topics like the nature of amateur radio, technical basics, transmitter/receiver fundamentals, and antennas, providing a framework for instructors to build their curriculum.

During a club's "Filetto Day" event, a comparative field test was conducted between a **Buddipole** antenna and a homemade 20/40-meter wire dipole. The author, IW5EDI, performed this personal evaluation from a mountain top at 1500 meters above sea level, utilizing a Yaesu FT-857D transceiver to switch between antennas. The observations on the 20-meter band indicated that the wire dipole consistently delivered significantly stronger signals compared to the Buddipole. Additionally, the Buddipole exhibited higher levels of **QRM** during the listening tests. The commercial Buddipole, known for its multiband capability and compact size with a self-supporting tripod, was contrasted with the simpler, larger wire dipole, which required a fiberglass fish pole for support. This direct comparison highlights practical differences in performance and deployment between a popular portable commercial antenna and a basic wire antenna in a real-world operating environment.

The current, the voltage, the impedance, the bandwidth, the polarization, and how the earth influences the famous radiation pattern.

An overview of the basics of the horn antenna used in RF microwave applications.

Summary, tutorial about the basics of what is a waveguide and the basic waveguide theory.

Antenna directivity and gain are fundamental concepts for any radio operator, as this article from _Electronics Notes_ explains. Real-world antenna designs, unlike theoretical isotropic radiators, do not radiate equally in all directions; their radiation patterns are often visualized using **polar diagrams**. These diagrams illustrate how power is focused in desired directions, crucial for both transmitting and receiving applications. The article clarifies how antenna performance is identical for both transmission and reception, a key principle for understanding antenna specifications. Operators often encounter terms like _beamwidth_, which defines the angle where power falls to half its maximum level, or -3dB. Understanding this parameter is vital for accurately orienting directional antennas like a Yagi. The discussion also differentiates between antenna gain expressed in dBd (decibels over a dipole) and dBi (decibels over an isotropic source), noting that dBi figures will always be **2.1 dB** higher than dBd. This distinction is critical when comparing antenna specifications to ensure an accurate assessment of performance. Furthermore, the article touches on the front-to-back ratio, another important metric for directional antennas, and the balance between maximizing forward gain and achieving an optimal front-to-back ratio.

This variation of the basic horizontal, half wavelength flat top dipole has proven to be a simple, effective antenna suitable for both home and portable use.

Online calculator for J-Pole antennas. The J-pole antenna consists of a short and a long vertical pole with a feed point near the bottom. The antenna looks like the letter J, hence the name J-pole antenna.

Distributed Antenna Systems technology used for gaining better coverage and using a lower power.

A summary, overview or tutorial covering the basics of Meteor Scatter or Meteor Burst Communications, a form of radio signal propagation often used at VHF.

Utility-Driven Tradeoff Analysis, if you want to geto on the microwave bands , you will have to choose the proper antenna for your operating conditions. How to decide is not always easy, and you may also decide to build your own antenna.

Smart antennas or the adaptive antenna array and smart antenna technology used with SDR, cognitive radio, MIMO, and other new technologies.

About antenna or aerial resonance and bandwidth and the impact of RF antenna resonance and bandwidth on radio communications systems.

Article on antenna feed impedance and the importance of matching RF andtennas to feeders, including notes on Radiation resistance, loss resistance, and efficiency are also detailed.

Basic anctenna theory, general information on antennas

Cmpter Electronics specializes in the design and manufacturing of RF coaxial connectors, RF adapters, and RF cable assemblies, serving diverse applications across datacom/telecom, automotive, instrumentation, aerospace, and defense sectors. Their product line includes RF coaxial terminations, attenuators, and waveguide to coax adapters, catering to specific needs in radio frequency systems. The company also offers precision adapters and connectors, alongside glass beads and test cable assemblies, indicating a focus on high-quality components for demanding RF environments. Their resource center provides valuable information, including an "RF Made Simple" section and a product catalog for download, which assists engineers and technicians in selecting appropriate components. The product named system helps in identifying specific parts, streamlining the procurement process for complex RF solutions. With a comprehensive range of RF coaxial cables and related tools, Cmpter Electronics positions itself as a key supplier for critical infrastructure requiring reliable signal integrity. Their offerings support a broad spectrum of RF applications, from basic connectivity to advanced test setups.

Sixty-meter repeaters typically use a 1 MHz frequency separation between input and output, while 2-meter repeaters commonly employ a **600 kHz** split and 70-centimeter repeaters use a **5 MHz** offset. This article details the fundamental technical principles of amateur voice repeaters, explaining how they extend VHF/UHF communication range by receiving on one frequency and simultaneously retransmitting on another. It covers essential components such as receivers, transmitters, filters, and antennas, often situated on elevated locations for optimal coverage. The resource delves into the critical challenge of _desensing_—where the repeater's strong transmit signal overpowers its own receiver—and the engineering solutions employed, including antenna separation and the use of high-Q cavity filters. It also explores various control and timing systems, from basic squelch activation to more sophisticated microcontroller-based boards that manage functions like voice identification, time-out timers, and fault protection. Different access methods are discussed, including open access, toneburst, CTCSS subtone, and DTMF, each offering distinct advantages for managing repeater usage and mitigating interference. Furthermore, the article examines repeater linking, both conventional RF methods and modern internet-based solutions, highlighting how linking expands coverage and promotes activity across multiple repeaters or bands. It introduces less common repeater types such as 'parrot' repeaters, which use a single frequency and digital voice recording, and linear translators, capable of relaying multiple signals and modes simultaneously across different bands, often found in amateur satellites.

An article describing basic concepts of antenna radiation, and in particular directional antennas like Yagi antennas or Quad antennas and how they determine the direction or signals.