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W3HH wide-band wire antenna Article in French. The W3HH antenna, also known as the Terminated Folded Dipole (T2FD), is a compact, broadband antenna for amateur radio. It operates at an angle of 20 to 40 degrees and covers frequencies from 3 to 30 MHz. The antenna features a total length of one-third of the wavelength at its lowest frequency and is fed using a 1:4 BALUN transformer for impedance matching. A termination resistor around 390 Ω optimizes performance, making it suitable for various amateur radio applications while being easy to construct and install.

Design for a quarter wave vertical antenna, for the top band in use at V31YN

1:49 UNUN using two stacked FT240-43 cores for end fed halfwave antenna. To match the end fed half wave antenna to the coaxial feeder, it is necessary to have a matching network or transmission line transformer.

1.5 dB of matched line loss can be calculated for a given transmission line using this online tool, which employs a model calibrated from empirical data. The calculator allows radio amateurs to input specific transmission line types, such as _RG-8_ or _RG-58_, and then determine the expected signal attenuation. This is crucial for optimizing antenna system efficiency and understanding power delivery to the radiating element, especially for HF and VHF operations where feedline losses can significantly impact performance. Beyond matched loss, the calculator also provides an estimate for mismatched loss if the Standing Wave Ratio (SWR) is specified. This feature helps operators quantify the additional power loss due to impedance discontinuities between the transceiver, feedline, and antenna, which is a common concern in amateur radio installations. Accurate loss calculations are vital for effective station design and for predicting actual radiated power. The tool's utility extends to various operating scenarios, from fixed station setups to portable deployments, aiding in the selection of appropriate feedline lengths and types to minimize signal degradation. Understanding these losses is a fundamental aspect of maximizing the effectiveness of any amateur radio antenna system.

Sw tool to design point-to-point multi-hop microwave links and networks, 400MHz to 58 GHz. Site/Hop Configuration; Customized Antenna & Radio Equipment Libraries; Link Budget; Path Profile Analysis ,clearance, reflections; import path profiles from SRTM maps, free download.

A 102-inch vertical whip, commonly a CB antenna, forms the core of this low-profile 10-meter antenna design, optimized for the 28 MHz band. The construction details specify three 8-foot radials made from scrap wire, connected to a common point. This simple yet effective setup is designed for ease of construction and deployment, making it accessible for operators with limited space or materials. The design emphasizes using readily available components, including PVC pipe for the mast and a SO-239 connector for the feedline, ensuring a straightforward build process for a resonant quarter-wave vertical. Field results indicate that this antenna provides good performance for local and DX contacts on 10 meters, despite its compact footprint. The author, N8WRL, shares practical insights into its construction and tuning, highlighting its suitability for temporary or permanent installations where a full-sized antenna might be impractical. Comparisons to more complex designs suggest that this low-profile vertical offers a respectable signal-to-noise ratio and effective radiated power for its size, proving that simple designs can yield satisfying on-air results.

Broadband instruments, R and microwave components and filters, field analyzers, spectrum analyzers

Storm Products Company provides high-value, interconnect products, subsystems, and services to electronics, communications, and instrumentation markets worldwide. Products include Electronic and Microwave cable assemblies, components, and test products.

RF/Microwave Simulator for Puppy Linux by WN2A

This web article details the construction of a 4-meter band coaxial dipole antenna, designed for operation between **70.000 MHz and 70.500 MHz**. The resource provides a bill of materials and step-by-step assembly instructions for a half-wave dipole constructed from _RG-58_ coaxial cable. The design specifies a direct 50 ohm feedpoint impedance, eliminating the need for an external matching network. Construction photographs illustrate the stripping and soldering processes for the coaxial cable elements, ensuring proper electrical connection and physical integrity. The article includes specific dimensions for the radiating elements, derived from calculations for the 70 MHz band. The project outlines the physical dimensions required for resonance at 70 MHz, with the outer braid forming one half and the inner conductor forming the other. The feedline connection is directly to the coaxial dipole's center, maintaining a 50 ohm characteristic impedance. While the article does not present SWR plots or VNA sweeps, it focuses on the mechanical construction and dimensional accuracy for achieving a functional 4-meter dipole. The design is intended for fixed station use, with no specific mention of polarization or height above ground, but implies a standard horizontal orientation for dipole operation. DXZone Focus: Web Article | 4m Coaxial Dipole | Construction Guide | 50 ohm Feed

Two different ways to create autotransformer for end fed half wave wire antennas, by using ferrite or air core.

DK8KW Longwave Information

Aka Circular Waveguide Antenna. This online antenna calculator let you plan your cantenna for the desired frequency of operation, giving the Can diameter you have available.

European relay station broadcasting every weekend on short-wave to all of Europe, Northern Africa and the Middle East on 13840 kHz.

Multi-frequency radio interferometers

Amplifiers, filters, attenuators, mixers, PLL, switches and frequency dividers, signal generators, power detectors, transimpedance amplifiers, variable gain amplifiers and more

Dealer of electronic test equipment dealers since 1977 equipment manufactured by Tektronix, Hewlett Packard, General Radio, Dranetz, Bird, Fluke, ENI, ESI, Wavetek, Narda, Keithley, Weinschel, Microlab/FXR, Systron Donner, Kepco, Lambda

News, frequency guides and programme information, on shortwave and other international media.

Online VSWR Voltage Standing Wave Ratio Calculator

Home of FM & TV DX in the UK

Maxdao: offer you 7/16, N coaxial connectors, jumper cables, feeder clamps and grouding kits, surge arresters & brackets, wall entries and microwave components used in base tower, power dividers, couplers

A simple VHF quarter wave antenna from PL25

This LPDA calculator is based on the design procedure as described by L. B. Cebik, W4RNL (SK) in the 21st edition of The ARRL Antenna Handbook.

Amateur projects to investigate radiowave propagation - G3PLX's chirp project, ionosonde database, and more

Demonstrates the complete design and development process for a **Low Noise Microwave Amplifier** (LNA), beginning with conceptual design and progressing through prototyping. The tutorial series covers the initial stages of a single-ended first gain stage, focusing on critical parameters such as noise figure, gain, and stability. It systematically details the theoretical underpinnings and practical considerations for achieving optimal performance in microwave frequency applications. This resource provides a structured approach to LNA construction, enabling radio amateurs and RF engineers to understand the iterative steps involved in realizing high-performance receive-side amplification. It offers insights into component selection, impedance matching networks, and the measurement techniques required to validate design specifications, particularly for **microwave** band operation where noise performance is paramount.

OK0EU is short-wave QRP beacon set up by the OK QRP Club and supported by the Institute of Atmospheric Physics of the Academy of Sciences of the Czech Republic (UFA).

A collection of ad Hoc empirical comments on VHF radio waves propagation by Pete Heins N6ZE

everything RF is a web portal for RF & Microwave Engineers providing News, Design Articles, Information on new products and a component search engine which helps you find the RF & Microwave Components that are right for you.

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

Inches and meters Javascript Wavelength Calculator allow to input a frequency in MHz and calculate wavelenght in several units considering also fractions of wavelenght and the velocity factor. Includes an usefull inch to meter converter

K1JJ presents a compilation of insights regarding vertical radial ground systems, specifically applied to 160m vertical arrays. The resource details 19 distinct observations and recommendations, emphasizing that ground radials primarily reduce ground losses rather than influencing pattern formation. It explains that RF current flows inefficiently through average soil, necessitating copper radials to create a low-resistance path back to the antenna base. The content suggests that **50-60 radials** are generally sufficient to achieve optimal efficiency, with diminishing returns beyond that number, and that radials should be laid on the surface for best performance. The discussion also addresses practical aspects such as wire gauge, installation techniques using 'U' shaped staples, and methods for connecting radials in multi-element arrays. It highlights the importance of radial length, stating that 1/4 wave radials are a crucial minimum, and that for 160m, radials should be at least _100 feet_ long. The resource critically examines the efficacy of elevated radials versus ground radials, noting that while a few elevated radials may suffice for VHF, HF applications, particularly on 160m, require extensive ground radial systems to efficiently collect RF currents in the near field. It also touches on the impact of radial systems on parasitic elements and the significance of symmetrical radial patterns for minimizing losses. Further practical advice includes wire type recommendations, proper soldering and weatherproofing techniques for radial connections, and considerations for integrating steel towers into the ground system. The author shares personal experience with installing 60 quarter-wave and half-wave radials under each of three in-line verticals, expressing satisfaction with the results.

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

The collinear antenna, or Marconi-Franklin antenna, is an omnidirectional, high-gain antenna composed of in-phase half-wave dipoles aligned vertically. By using quarter-wave transmission line segments, it maximizes gain at a low horizon angle, outperforming a half-wave dipole. Adding segments increases gain but narrows bandwidth. A popular DIY version, the CoCo antenna, uses half-wave coaxial cable segments connected by non-radiating transmission lines. Built with stable velocity factor cables, a matching quarter-wave sleeve balun, and ferrite rings for attenuation, the antenna achieves performance comparable to commercial models.

Over 20 distinct discussion categories are available on the Amateur Radio Discussion forum, encompassing a wide array of topics relevant to radio enthusiasts in the UK and beyond. The platform facilitates exchanges on technical aspects of amateur radio, including antenna designs, equipment reviews, and operating practices across different bands. Specific sections are dedicated to CB radio and shortwave listening, broadening its appeal beyond licensed amateurs. The forum's structure supports detailed discussions on operational challenges like the "Work All Postcodes" award, which encourages contacts across UK postal districts. Members can track personal statistics, manage contacts, and engage in challenges, fostering community participation and skill development. The resource provides a centralized hub for sharing knowledge and experiences among radio operators, offering practical insights into diverse radio communication facets.

Introduction to NVIS antenna and NVIS propagation. A simple NVIS antenna can be constructed as shown in this article

International Public Access Radio via IRRS Shortwave and Internet Radio NEXUS via MP3 streaming audio

The Shortwave Radio Audio Archive is a collection of shortwave radio recordings in both the form of a podcast and blog with embedded audio. The collection grows every day and includes both historic and modern day shortwave radio audio recordings

A shortwave radio listeners log book runs on Windows and MacOS Catalina and above. The KB6IBB SWL Logger is a program designed for the shortwave radio listener. It offers shortwave specific logging of stations, with most tasks handled automatically. The program also incorporates the use of EiBi shortwave database for logging and looking up various known shortwave stations world wide.

A Horn antenna by WE3HHT

A monoband delta loop antenna for the 7 MHz. This vertically polarized DX Antenna is a full wavelength sngle side antenna and has a total length of 42.3 meters (137,1 inch) Can be easily setup with a flag pole or fishing pole as center top mast. For optimal performance lower side should be at 2 meter above the ground. This antenna offers a low radiation angle and 1 DB Gain.

About experiments and measurements on loading coils using net standing wave current

Complete collection of the four main parts of this excellet research on modelling and designing half wave dipole antennas for 40 meters band, covering all aspects beginning from full wave length antennas, to shortened, loaded and reshaped dipoles

The program consists of tabbed pages for various antenna and transmission line calculation. You can compute the values for an inverted L network that will allow you to match the 50 ohm output of the radio, or you can compute the necessary length in the units of choice for a 5/8 wave vertical for 10 meter band.

Naptech buys and sells quality test equipment from hp, tektronix, including spectrum analyzers & peripherals, oscilloscope, frequency counters timers, signal generators, multimeters & voltmeters, RF & power meters, microwave amplifiers

Cobham Microwave has a long term experience in Microwave Systems and Components. Their five areas of capabilities are Systems and Components: Diodes & Modules, Ferrite Devices, RF Filters, and Waveguides.

The Utility DXers Forum (UDXF) provides a centralized platform for exchanging news and information concerning utility radio stations and signals operating within the 0 to 30 MHz spectrum. It specifically excludes broadcasting, pirate, and amateur radio transmissions, concentrating instead on a diverse array of other signals. The resource details the types of stations covered, including maritime coastal and ship stations, aeronautical ground and aircraft communications (voice, HFDL, Selcalls, Volmet), military operations, various beacons (NDB, driftnet, propagation, pirate, high-frequency), fax transmissions, numbers stations, diplomatic communications, clandestines, and other unusual signals. Further content addresses radar systems such as Over-the-Horizon, Ocean Wave, and CODAR, alongside ionosondes, chirpsounders, ALE-systems, Selcall-systems, and tone calls. Experimental stations and standard frequency and time stations are also within its scope. The forum also acknowledges utility radio-related amateur events like the International Lighthouse Weekend and Night of Nights, providing a broader context for listeners. The site offers sections for modes, hardware, software, a utility radio archive, digital BC & HF conditions, and a utility radio club archive, along with QSLs and pennants.

RF / IF Microwave components DC to 20 GHz

Radios 4 you inc. where quality radios and other electronic products are blended with fair prices to produce excellent value for you. radios specializes in shortwave radios, solar rechargeable radios, am radios, and fm radios for sale.

Examines Radio Frequency Systems (RFS), a manufacturer specializing in high-performance cable solutions for diverse communication infrastructures. The company, with over 120 years of heritage, focuses on designing and producing robust, long-life connectivity systems, including _low loss foam dielectric RF cable_ and _premium radiating cable_. RFS's product range supports critical applications in cellular networks, microwave antenna systems, and specialized installations within buildings and tunnels. The resource highlights RFS's commitment to innovation, addressing emerging industry standards like _FRMCS_ for railway communication and advanced fiber solutions for data centers. It also details the company's manufacturing capabilities in Hannover, Germany, emphasizing the quality and reliability associated with _Made in Germany_ products. The content covers various connectivity landscapes, from urban solutions for connected cities to private 5G credentials and future plans. Specific product categories include _fiber, power & hybrid cable_, and _low loss high power air dielectric RF cable_, showcasing their broad portfolio for complex RF environments.

Restored vintage amateur radio, shortwave & other electronics from the vacuum tube era! Specialists in restored Ham Radio boatanchors