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A folded wire antenna for 160 meters as appeared on 73 amateur radio magazine june 1997

Build your own multi-band mobile ham antenna with a Hamstick

ARRL comparison of HF transceivers, including Elekraft, TenTec,Icom, Yaesu and Kenwood recent transceivers based on QST product reviews

This project was published in the April 2004 issue of the Australian magazine Amateur Radio, and has been designed using parts which are very readily available.

IC‐2300 MARS/CAP mod expanded frequency range 136‐174 MHz

J-pole designs, for 50 to 450 MHz by WA6ESC

English version of the Yaesu FT-7800 operating manual

A project for a homemade multiband Hexbeam antenna for 10, 12, 15, 17 and 20 meters

F5DQK repairing and swr measurement tests of a Cushcraft R7 Antenna

Linpac is an extensible Linux packet terminal that supports easy access to concurrent connections (streams), PBBS/FBB forwarding, and support for adding external commands

The HF ham bands can be mysterious. Some work at night, some during the day. Some seem to be good for long distance contacts while some are better for nearby contacts. Even worse, they change tremendously from hour to hour and day to day. An overview on operating on HF amateur radio bands

A Half wave antenna has a high impedance feed point. This can be matched using a 1/4 wave stub matching section and converts the 40m vertical into an L-shaped 20m J-Pole antenna. The 300 ohm feeder used for this purpose must be kept away from the ground.

Original article published on February 1992 on 73 Amateur Radio Today about the 2m and 70 cm copper cactus J-pole antenna

Windows open source packet radio decoder. Decodes AFSK1200, AFSK2400, HAPN4800, and FSK9600 packet data with a radio connected to your pc sound device.

Official, and updated CQ Magazine Countries and Zone List available in various formats, text, word and excel formats.

Step by step instructions for setting up N1MM Logger to communicate with the TS-590S using the USB connection

A dipole for 2m, 4m, 6m band an hamdwritten note for a homemade vhf antenna that can be tuned across the VHF band

Yagi-logper is a linux GPL program to model a Yagi or Log-periodic antennas with horizontal cylindrical dipoles.

Codec2, an open-source speech codec, targets low bit rate voice communication, specifically designed for digital radio applications operating within constrained bandwidths. The project focuses on achieving intelligible speech quality at data rates around 2400 bits per second, a critical parameter for efficient spectrum utilization in amateur radio. Its development addresses the need for robust voice transmission over channels where higher bit rate codecs would be impractical or inefficient. The resource details the technical specifications and implementation aspects of Codec2, including its underlying algorithms and performance characteristics. It provides insights into how the codec processes speech to achieve its low bit rate, outlining the various coding schemes and their impact on voice fidelity and error resilience. The information presented allows radio amateurs and developers to understand the codec's operational principles and its suitability for integration into custom digital communication systems. Applications for Codec2 extend to digital voice modes on HF and VHF bands, enabling more users to share limited spectrum resources. The project's open-source nature facilitates community contributions and widespread adoption, fostering innovation in digital amateur radio. It represents a significant effort to provide a freely available, high-performance speech coding solution for the amateur radio community.

A Working analysis of the gamma match problem that gives useful practical results in a article dated April 1969.

Cheap Antennas for the AMSAT LEO Kent Britain WA5VJB

TAHO.EXE, an open-source software, facilitates the creation of APRS maps for _UI-View_ by converting free data from _OpenStreetMap_ into the required *.JPG and *.INF file formats. This utility, developed by Dimitri Junker with specific UI-View format support added at the request of HB9DTX, streamlines the process of integrating detailed geographical information into the _UI-View_ platform. It operates on Windows, generating map files with border coordinates in just a few clicks, eliminating the tedious manual creation of *.INF files for custom maps. This converter allows UI-View users to leverage the continuously updated and community-contributed data of OpenStreetMap, which often surpasses commercial map quality in specific regions. The process is straightforward, with a detailed step-by-step guide available on the OpenStreetMap wiki, translated into French and German. TAHO.EXE significantly enhances the utility of UI-View by providing a readily accessible and continuously improving source of detailed, current geographical maps for displaying APRS station positions and objects.

A free to download and print, paper log sheet useful for portable amateur radio operations, in a PDF file.

Every ham needs an RF power meter. Here is a high performance unit to build at home.

Ham radio resources about qrp, dx, logging, contesting, includes lots of links to FT817 resources on the web

Over 47 full-screen maps are available within _NAOMI_ (North American Overlay Mapper), a free Windows program designed for US and Canadian amateur radio enthusiasts. This mapping suite includes 9 backgrounds such as CQ Zones, ITU Zones, and ARRL Sections, along with 16 foreground layers like Counties, Areacodes, and Grid Locators. Users can calculate distances and bearings, track real-time mouse positions with continuous Grid-Locator data, and integrate with APRS for live station tracking via the FindU database. For a global perspective, the _Global Overlay Mapper_ (GOM) provides a world map, 8 continental maps, and 29 sub-continental maps, all with 12 active layers including Country Outlines, CQ/ITU Zones, and Prefix information. Both NAOMI and GOM offer feature-locate systems to jump to positions based on prefixes, capital cities, or Grid Locators, and provide customized beam headings and distance displays. The site also features _LogView_, a post-contest log visualization tool that analyzes Cabrillo-format logs by plotting QSOs on maps, supporting over 30 major contests like CQWW and ARRL DX, and allowing comparison with published results.

xdx is a dedicated Linux network client for amateur radio operators who want to exchange DX (long distance) radio information

A comprehensive resource center with DX aids, live propagation, callsign searches, news and bulletins, maps, and more by NW7US

Unix or linux programme atlc calculates the impedance of electrical transmission lines of totally arbitrary cross section.

The document provides a comprehensive overview of baluns, which are devices used to connect balanced loads, like dipole antennas, to unbalanced inputs, such as coaxial cables. It covers various types of baluns, including voltage and current baluns, and their design, construction, and testing. The text discusses the importance of baluns in preventing RF currents on coax shields and their applications in Ham radio setups. It also includes practical advice on selecting and using baluns based on antenna impedance and power ratings, along with detailed performance evaluations and construction tips for different balun configurations.

URLog, version 0.1.10, functions as a freeware amateur radio logging application designed for basic QSO record-keeping. The software provides core functionalities for inputting contact details, including callsign, date, time, frequency, and mode, which are fundamental for maintaining an amateur radio logbook. Its design emphasizes ease of use, making it accessible for operators who require straightforward logging capabilities without extensive advanced features. The application's utility lies in its simplicity for everyday logging tasks, particularly for those who prefer a local software solution over web-based loggers. While specific data formats supported are not detailed, standard logging practices suggest ADIF compatibility for export, facilitating integration with other ham radio software or online logbooks. The software's compact download size of approximately 4.5 MB indicates a lean installation, minimizing system resource usage.

A combination of Fldigi and Flmsg for portable devices running Android used for NBEMS

If you have space constraint at your QTH for a HF antenna, you can try contructing this HF magnetic loop antenna for 40-20 meters bands

WM7D's FT100 resource page, dedicated to providing information about and resources for, the FT100

The Smith Chart was originally created many years ago as an RF engineering aid by Phillip Smith of RCA.These pages includes extesnive documentation on smith carts.

Building an Open Source Arduino APRS Tracker with LCD & GPS ( SVTrackR )

Amateur radio open source log program written in PHP. Put your log online for visitors to browse in real time. Access your log from any web browse, can run under windows linux and macos with apache, mysql and php

A sourge arrestor for PL 259 connectors. A voltage surge arrestor to limit the voltage that may come back down the wire or coax after there has been static build up

Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit. After that simulation has finished you can view the simulation results on a presentation page or window. Run on Linux.

A 21 MHz Four Square Beam Antenna This popular antenna for the lower bands, can also work well on 15 meters, QST Article

Service manual in PDF Format for the Yaesu FT-7800 transceiver

An end fed 20 meter half wave antenna

FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display for Linux, offering various algorithms for audio processing in the frequency domain and an interactive GUI. It provides high-resolution spectral displays like scrolling-raster spectrograms and energy vs frequency plots.

UR5FCM Log provides a centralized logging solution for amateur radio operators, designed to manage daily radio communications and integrate various digital modes. This software functions as a primary working center for a radio station, facilitating the recording and management of QSOs across different operating aspects. Since version 1.1.61, UR5FCM Log has incorporated enhanced features for digital mode operations, specifically supporting RTTY, BPSK, and SSTV. The application aims to streamline the logging process, offering tools for QSL management and general station record-keeping. It is developed for the Windows operating system, providing a graphical user interface for ease of use. The software includes capabilities for tracking various contact details and supports common amateur radio data formats for log exchange. Its development history spans from 2002 to 2005, with Igor I. Krinetsky credited as the author.

A scanned PDF of this interesting book on HF Dipole antennas published by Stanford Research Institute

Schematic of Yaesu FT-857 main board original jumpers based on different radio type

For those who are interested in telegraphy, for those who would like to learn it, for those who love it, and for those who want to improve their skills in it

An excellently presented article on the design and construction of a medium wave DX Antenna

In this article K3DAV show a very simple way to make an RF choke coil that will remove your RF feedback troubles

A complete guide to magnetic loop antenna construction, with analysis of multi-turn and single-turn magneti loops, and and insight on choosing the optimal capacitor, or homebrewing your own butterfly capacitor