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An Energy Analysis at an Impedance Discontinuity in an RF Transmission Line

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 homebrew audio mixer for the ham shack by GW6ITJ

An home made low pass filter for 70 MHz by IK0VAQ

Want to operate on 40 meters but only have a space a little over 16X16 ? Try this antenna.

An 80m transceiver using just 14 parts plus crystal and earpiece

A simplified Guide to the FT8. Dxpedition mode. By Stefano IK2HKT – Rel. 2.0.0 - January 2019. This document explains how to configure WSJT to work on F/H mode DXPedtions, how to operate and make a call to a dxpedition calling CQ in FT8 Fox Mode.

Slot cubes are folded skeleton slot antennas with widened, folded dipoles bent into a cube to reduce size. QST Article 12 2019

Digital voice on Amateur Radio - devoted to the discussion of digitized voice and data over analog emission modes.

This is a presentation used at OVARC on the LindenBlad antenna construction. The presentation cover several topics about this antenna, from the basic antenna design, to the guide on how to contruct a custom lindenblad antenna for the 2 meters band and and 70 centimenters band.

An home made FETer QRP transceiver for the 80 meters band

There are many designs for building preamps each with their own advantages and disvantages. In this PDF Article author reviews several different types.

Free Android app that tracks and alerts on ISS passes with specified criteria.

Article from 73 Amateur Radio Today about experimenting on ferrite loops transmitting loop antennas for 80 and 160 meters bands.

Design and build a 6 meter 2-element Moxon antenna mostly from available aluminum tubing and angle stock.

About Coax Traps, NC4FB examine the operation of coax traps through modeling.

Hone your Morse code skills with this entry-level project. Article includes the full schematic of the CW Trainer, describes the sketch and how to operate the morse code trainer.

This document is a must read for anyone considering building a good low cost HF multi-band antenna system. The author combine in this document four important ingredients to produce simple but effective antenna system, like antennas of non resonant length, line attenuation, the transmatch and the balun

A 160W linear amplifier for 4 meters band based on GI0GDP

The author who works successfully via EME on this band wants to describe his own yagi design and give some of hints for the construction. by Heinrich F. Reckemeyer, DJ9YW

Cushcraft XM240 transformation into a Moxon antenna by W6NL

Have you ever thought of setting up a portable HF station for an activity ?

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

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

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 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.

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