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Nifty E-Z Guide to EchoLink Operation A comprehensive guide for installing and operating EchoLink.

A complete EmComm portable station article on eham.net by K9RFZ

Since they were first described by the French mathematician Benoit Mandelbrot in the mid-1970s, repeating geometric figures known as fractals have fascinated computer scientists, mathematicians and graphic artists.

A portable USB SO2R box made with Arduino

The FieldComm Association, based in Central Virginia, operates as a specialized amateur radio club with a primary interest in emergency communications. Members engage in various technical aspects of radio, including digital modes, QRP operations, and DXing. The association provides a platform for hams to develop skills in field deployment and reliable communication under challenging conditions, often leveraging modern digital protocols. This organization's activities support the practical application of amateur radio for public service, emphasizing readiness and operational proficiency. Members collaborate on projects and share knowledge, fostering expertise in areas like portable station setup and efficient data transmission. The focus on emergency communications distinguishes its operational priorities from general interest clubs, aligning its efforts with community preparedness.

Amplifier repair and conversion, specialize in converting HF amplifiers to operate as monoband amps on 50 MHz

W-CODE is a professional digital mode decoder system capable to decode many digital signals on HF, VHF/UHF, SHF and SATELLITE bands.

Ultra-lightweight 2m Yagi for SOTA

Australia's largest range of Electronic Kits & Components In Stock for the Radio Experimenter, ATV, microwaves, HF Band pass filters

Radios, Antennas & More dealer from Texas USA

Topband and DX recordings and sound files on 160 meters band

Tubes, military manuals and surpluss

European Telecommunications Satellite Organization

This manual is an edited version of the GAP supplied document, complete with diagrams, pictures and assembling notes by Mitch Baum AE2A. This is 29 pages document in PDF Format.

An interesting article on guanella baluns that cover several aspects of homebrewing 1:1 and 4:1 current baluns by KN9B

Free programming software for the Yaesu VX-7 and VX-7R.

This circuit came out of some work done for two antenna analysers

Presents the Amateur Radio on the International Space Station (ARISS) program, a global educational initiative facilitating direct communication between students and astronauts via amateur radio. It outlines the operational framework for scheduled school contacts, detailing the technical requirements for ground stations and the typical Q&A format used during these events. The program utilizes VHF/UHF frequencies for voice and packet radio communications, enabling students to engage with crew members aboard the ISS. ARISS supports various educational objectives, promoting STEM fields through hands-on radio experience. The resource provides information on how schools can apply for contacts, the selection process, and preparation guidelines. It also covers the history of amateur radio in space, including past missions and the evolution of equipment used on the ISS. Regular updates on contact opportunities, operational status, and technical specifications for ARISS hardware are provided.

A free small database program for Palm OS that allows you to log ham radio contacts. You can log the call sign, name, date, time and frequency of the contact.

A nice post on Make: on homebrewing a multiband antenna for amateur radio portable operations

Kentucky farmer invents wireless telephone! But was it radio? Facts and folklore about Nathan Stubblefield by Bob Lochte.

Computers, TV's, and Switching Systems can cause noises to your receiver

Globe-S for RTL1090 is a light radar viewer for RTL1090. It communciates via a HTTP interface and can be interfaced over long distances.

The QRZ.com callsign database serves as a fundamental resource for amateur radio operators worldwide, enabling rapid lookup of station information. Each entry, such as the one for _HB9DSP_, typically includes essential details for making and confirming contacts. Operators can find QSL routes, often indicating preferences like "via bureau or direct," which streamlines the exchange of QSL cards for award credit. Beyond basic contact data, these pages frequently offer insights into an operator's activities, including their participation in contests or DXpeditions. The platform also tracks metrics like "XML Subscriber Lookups," showing how often a callsign's data has been programmatically accessed, totaling **77670** for this specific entry. This functionality is crucial for logging software and other automated systems that rely on accurate, up-to-the-minute amateur radio data. While the page title mentions a "Home made multiband MOXON" antenna, the actual content primarily focuses on the callsign's biographical data within the _QRZ_ database.

Building the MFJ Cub QRP transceiver kit for 20 meters band by G4ILO

Kingston Amateur Radio Club Articles Dave Lawrence, VA3ORP

Ten essential tips and truisms for understanding HF antenna: Non-resonant wire dipole antennas fed with open-wire line and an antenna tuner can function effectively as multiband antennas, as detailed in "The Classic Multiband Dipole Antenna" by WB8IMY in March 2004 QST. Coaxial cable, unlike balanced parallel-wire feed lines, can cause RF to travel on the outer shield braid, leading to RF feedback to the station; a 1:1 balun at the dipole center can mitigate this by isolating the unbalanced coaxial feed line. Antenna gain is achieved by shaping and directing RF energy, with beam antennas concentrating power in a specific direction, and wire antennas also exhibiting shaped radiation patterns. An antenna tuner's primary role is to match the transceiver's 50-ohm output to the antenna system's impedance, allowing modern transceivers to deliver full power. Wire antennas do not always require center feeding; end-fed long wires or off-center-fed dipoles (like the Windom) can be used, though they often necessitate an antenna tuner and a counterpoise or radial network. Dipole antennas do not need to be perfectly horizontal; their legs can be bent or inclined, which affects feed point impedance and may require SWR experimentation with coaxial feed. Vertical antennas shorter than a half wavelength require an efficient ground system, typically comprising elevated or buried radial wires, with more radials generally leading to better efficiency. A 1:1 SWR indicates an impedance match but does not guarantee antenna efficiency; an inefficient vertical antenna with a poor ground system can show a low SWR while wasting most RF as heat. Investing in high-quality, low-loss feed line, especially coaxial cable, is crucial for maximizing RF signal transfer and overall antenna system performance.

NU-Tech is a powerful DSP platform to validate and real-time debug complex algorithms, simply relying on a common PC. Thanks to an easy plug-in architecture, the developer can write his own NUTSs (NU-Tech Satellites) in C++ and immediately plug them into the graphical interface design environment.

Tencom, located near Toledo, Ohio is dedicated to the pultrusion of fiberglass composite products. This includes solid rods, conductor rods, tubes and a variety of custom profiles.

Experiences with Loop antennas at G3YMC include some loop antenna tests and theory by G3LHZ

In the VLF portion of the spectrum it is easy to listen to the emissions created by the Earth itself. These emissions are generated by many different mechanisms and are often beautiful to listen to. Coverage on LF and MF frequencies

Supplying over 2000 different vacuum tube types, valves, grid caps, sockets and capacitors. It is easy for Antique collectors, Ham radio operators, audio enthusiasts, broadcast enthusiasts and amateur radio hobbyists to buy, sell and trade vacuum tubes, electron tubes, audio tubes, valves, grid caps, sockets and capacitors

We are the premier Amateur Radio Club in the Edinburgh area, since our formation in 1984 we have done much to raise the profile of our hobby in the area.

A home made project for a 3 to 12 MHz signal generator

N9TEW is supplier of vacuum tubes for ham,audio & antique radio purposes.

The WaveNode WN-1 is a precision, full-featured Amateur Radio Station Monitoring System which now includes Audio Announcing for RF power, SWR, and DC monitoring using HF and UHF remote sensors.

ACARS decoder app for the iPad, iPhone, and iPad Touch

German DOK award program management windows software by IK6CAC

A handy piece of test equipment useful for HF bands, can absorb a 200W modulated carrier for almost 2 minutes. It is housed in a tin and part filled with dry sand that helps in power dissipation

The HyGain LJ-153BA a monoband 3 element Yagi, designed for the 15 m band 21.00 - 21.45 MHz

The Patch Antenna Array was constructed and used for various satellite up and down links at my previous residence in Melbourne, Victoria from 2003 - 2007

Specialize in engineering, design and repair of all rf equipment. Dealer for two way radios, scanners, shortwave radios, wi-fi antennas, wifi amplifiers. Based in Fortuna, California.

Here's a tale of early '70s vacuum tubes, mainly from the viewpoint of amateur radio.

Shareware windows program to manage IOTA contacts and IOTA awards by IK6CAC

A fully equipped amateur radio mobile radio shack by VE6AB

A 17 3/4-inch radiating element and 18 3/4-inch ground plane radials form the basis of this quarter-wave ground plane antenna for 2 meters FM. The design, attributed to AA1PG, utilizes a panel-mount SO-239 UHF connector and three lengths of #12 copper wire, with a total material cost estimated at $3.00. Construction involves soldering the elements directly to the SO-239, emphasizing thorough solder flow for robust connections. Recommended feedline includes _RG-8X_ for longer runs, with _RG-58_ acceptable for shorter lengths, cautioning against _RG-174_ for VHF applications due to high loss. The antenna is designed for elevated deployment, such as in trees or on roof gables, to maximize line-of-sight propagation. It aims to improve repeater access compared to typical rubber duck antennas, even with low power output.

This article is about a simple vertical end-fed-half-wave wire antenna for 10 meters that can be used in case of restricted space.

Constructing a mobile HF antenna presents unique challenges, particularly when aiming for multiband operation and robust mechanical stability. This project details N1GY's adaptation of the KM4IE $20 antenna and the _Texas Bugcatcher_ design, focusing on practical build considerations and on-the-road performance. The author shares insights from winding coils on 2-inch PVC forms and integrating a salvaged fiberglass core from an old Hamstick-style antenna to enhance structural integrity, preventing potential failures from stress on PVC joints. N1GY's build includes a custom matching coil and a commercially sourced MFJ loading coil, carefully integrated into the design. The article provides specific tap settings for bands from 75 meters to 15 meters, achieving SWRs as low as **1.2:1** on 40 meters and **1.6:1** on 75 meters. Mechanical testing involved driving at speeds up to 70 MPH on Interstate routes, confirming the antenna's durability and the effectiveness of its PVC brace system. Further modifications address real-world usability, such as simplifying antenna removal for car washes. The ground strap was updated with a Power Pole connector, and the brace attachment to the luggage rack was converted to wing nuts, reducing removal time from 30 minutes to approximately _five minutes_. This iterative design process highlights practical solutions for mobile HF operation.

The past and future of the Sun's solar cycle and possible impact on the Earth's climate.