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Introduction to WSPR beacons. Article describe WSPR2 and WSPR15 beaconing mode and include a frequency reference table for both WSPR modes

Adding 17 meter band to Mosley TA-33M yagi antenna

This is a schematic drawing of a project for the construction of a portable mast that can easily be made with PVC pipes.

Iambic Keying, Debunking the Myth by Marshall G. Emm, N1FN. A keying system controls transmitter activation, ranging from basic switches to electronic keyers that generate Morse code based on paddle input. Iambic keyers, introduced in the late 1950s, respond to simultaneous paddle closures with alternating dots and dashes. Despite touted efficiency, actual benefits are modest, offering about a 5% improvement in keystrokes, diminishing at higher speeds. Iambic keying's practical value is limited and may restrict sending speeds.

Technical supplement manual of the Yaesu FT-8800R in english

This is a QST Article published in January 1982 by W1FB D. Demaw and HH Beverage and is a complete review of the original article published in 1922, which updates and reivew the beverage antenna theory and developlment, explaining the antenna design of transformers and gives accurate reports on antenna general performance.

How can the current "flowing" out of the top of a mobile loading coil be greater than the current "flowing" into the bottom of the coil?

PDF manual of the TW4040 The Adventurer MonobanderTM TransWorld Antennas

APRS-Webserver, that presents aprs-data and maps for free using Google Maps api. The position data is imported from aprs.org, winlink.org and echolink.org. The map data are partially commercial and free. This server is for amateur radio purposes only.

Manual of the BD-35 Dual Band VHF UHF RF power amplifier by Mirage Amp

When I tell friends that I enjoy amateur radio contesting, their reaction is usually a quizzical stare. "What's that?" It is hard to explain in the span of a cocktail conversation, so here is the answer.

A december 2003 QST article to Build a condenser microphone that will perform like the costly commercial units by KT4QW

Getting started on RTTY contesting. A PDF by ED Muns, presented at CTU conterst university, about amateur radio RTTY Contesting

A Chaotic Collection of Keys, Paddles, and Bugs

A presentation of the Yagi Antennas, and other interesting tid-bits by Brian Mileshosky. The document provides an in-depth exploration of the Yagi-Uda antenna, detailing its historical development, design principles, and performance characteristics. Originally described in the 1920s, the Yagi antenna features a driven element and parasitic elements, including reflectors and directors, which collectively determine its behavior. The document highlights how element lengths, diameters, and spacing influence gain, impedance, and directivity. It also discusses the antenna's reciprocal nature and presents data on typical gain values for various element configurations. Additionally, the text covers practical considerations, such as the construction of a "Tape Measure Yagi" for amateur use, and touches on related antenna types like dipoles and their application in Near Vertical Incident Skywave (NVIS) communication.

A distributed capacity coaxial dipole antenna. The antenna is very broadbanded with a very flat swr on all band when setup of the antenna is done at the proper lenght and height.

An interesting presentation of a real multiband Fan Dipole antenna, optimized for better DX operation performances, considering the terrain, position, DX destination path and other influencing factors

An open design exercise in interface archaeology, that decodes the input from a classic Morse key to send twitter messages

30 meters beacon from UK. QRSS is a method of sending very slow morse code.

The ADIF Processor is an online application that visualizes amateur radio contacts from an ADIF log file using Google Earth. SOTA CSV log files can also be used. As well as allowing you to view and explore your contacts in Google Earth, you will be able to see a Markdown or text table of contacts, use the output ADIF file which contains QRZ.com data, accurate contact distances and fields populated from comments in the input file. Print QSL labels. One of the benefits of using the ADIF Processor before uploading/storing your ADIF file is detecting errors in callsigns and activity references (e.g. POTA or SOTA references).

A homemade band pass filter for the 30 meter band based on the original VE7BPO design

10MHz WSPR and QRSS Transmitter Project

How to make proper maintenance of your antenna. Fighting Antenna Corrosion is a QST article published in 1993 that helps on antenna maintenance works

How do two-wire reversible direction Beverages work, an excellent document that explains fundamentals of beverage antennas. This article details the design and performance of a reversible beverage antenna. Leveraging orthogonality between common mode and differential mode currents on a 2-wire line, this antenna facilitates independent reception from both ends. While common mode signals arrive and are summed on a transformer's secondary for common mode reception, differential mode signals induce anti-phase currents, providing individual reception. Various measurements explore impedance, transmission loss, and F/B ratio, highlighting the antenna's effectiveness and areas for improvement. Notably, increasing the antenna's height significantly improved performance.

Keyclicks and NB modifications for the Yaesu FT-1000MP Mark-V HF transceiver

A multiband vertical antenna for HF bands with elevated ground radials slant down at 45 degrees and acting also as guy wires.

The dipole shown in this document is installed in an inverted Vee configuration, with two leg elements on each side held parallel to each other by 21cm spacers. The upper leg is for 40m and the lower leg for 20m. The spacers are made of 7mm plastic garden hose support for garden sprayers cut to 21cm.

A free PDF from NASA about cubesat. Basic Concepts and Processes for First-Time CubeSat Developers. A great introduction document dedicated to Cubseat developers.

The page provides detailed information on a compact two-element yagi antenna, also known as the Moxon rectangle, specifically designed for the 17 meters band. It includes construction details, evolution history, performance data, and comparison with a 1/2 wave dipole antenna.

Three Yagi antennas for the six meters band by 9A7PJT. Include a 4 element yagi, a custom design 4 element, and a 5 element yagi with antennas pictures and design.

A 70 MHz QRP transverter project

A custom manual for the Yaesu FT 450 owners, tha includes system controls, factory reset procedure, procedural uses, memory management, programming and many more

Homebrewing portable antennas for field day operations

T2FD is a 600-900 ohms folded dipole, terminated with resistor. Feed impedance is coupled with 50/600 ohms voltage balun. It is a wide band antenna with rather low SWR over the full designed frequency range: antenna tuner is seldom needed.

Exploring these mysterious transmissions and how their strong following has created a niche in the community. Free article in PDF Format from QST November 2019

DIXPRS is an APRS Internet Gateway and Digipeater software for HAM radio use. It is designed to be portable and platform independent as much as possible. To reach this goal it is written in Python with minimal dependency considering older versions of operating systems and Python.

Receiver performance test of the Icom IC-7610 transceiver done by Rob Sherwood

MBU Cluster is simple android application for ham radio operators to view live the spots on mobile device. All the spots are refreshing every 60 seconds.

This application allows Ham Radio Operator to browse and search his LoTW QSL confirmations on his handheld device, and receive notifications when new QSL confirmations appear on Logbook of the World.

HF VHF UHF antenna ideas to be used for field days. All antennas are quick to set up and take down and offer proven performance and flexibility. Presentation offered by Mahoning Country ARES

A different implementation of the G7FEK HF multiband antenna with some adjustments and modifications

A selection of speakers or headphones for use with amateur radio equipment. Includes an interesting paragraph comparing Dynamic and Electret Condenser Microphones, but also about audio Equalization.

A simple drawing schematic of a portable field dipole for 14 MHz with dimensions in meters and instruction for setting up the antenna and to store the radial for easy transportation

If you want to design vertical antennas you can find all theory and formulas used to model a vertical aerial calculating capacitance, reactance, building the inductor and calculating resistances. Includes an excel spreadsheet to calculate efficiency.

This project is a Software Defined Radio Receiver. It has a frequency range of 24MHz 1.2GHz. It can demodulate AM, FM, USB, LSB with selectable bandwidths of 600, 2400, 2800, 3200 and 6400Hz. Using a simple RTL-SDR Dongle and Raspberry Pi 3 computer using GNU RADIO

A Microvert antenna by KD5RVX based on the original microvert concept by DL7PE. PDF includes a 20 foot portable PVC tower project

A nice review of the Acom 1000 HF and 6 meter RFpower amplifier by Acom in Dutch and with online google translation available. Includes pictures and notes of the popular amplifier by Acom.

This article is about a 4 element yagi VHF antenna designed to be easy to be assembled and suited for portable operations

Receiver performance review of the Kenwood TS-890S HF,50MHz,70MHz amateur radio transceiver by Sherwood Engineering

AudioXplorer is a sound analyzer software designed for Mac OSX, provide a real-time analysis window where you can visualize the sound spectrum and sonogram