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iota mapping project - a mapping resource for the IOTA (Islands On The Air) award program

The VersaBeacon is a frequency agile, modulation agile RF source using a DDS chip and minimal support circuitry. It covers a frequency span of 1MHz to 150MHz in 1 Hz steps and provides a variety of modulations

QJackRcd is a simple stereo recorder for Jack with few features as silence processing for automatic pause, file splitting, background file post-processing.

NHRC-2 Based Repeater Controller A perfect controller for a simple repeater or link, or portable/solar powered system.

The CAT and audio interface version 3 project by PA5CA presents a comprehensive solution for integrating amateur radio transceivers with computer sound cards, facilitating digital mode operation and CAT control. It includes detailed schematics for the interface circuitry, illustrating the isolation transformers for audio paths and optocouplers for CAT data lines, ensuring robust electrical separation between radio and PC. The resource also provides PCB layouts, enabling constructors to fabricate their own boards for this specific design. The project outlines the component selection and assembly process, emphasizing the use of readily available parts to build a reliable interface. It addresses common challenges in sound card interfacing, such as ground loops and RF interference, through its isolated design. This construction guide offers practical insights into building a functional interface, making it suitable for hams interested in DIY radio accessories for digital modes like FT8, RTTY, and PSK31.

A Tape Measure Beam Antenna for Radio Direction Finding based on WB2HOL design.

A well documented Heathkit SB-200 restoration project by NT1K

Homebrewing a vhf bicone antenna with 8 clothes hangers and 4 feet of Sch40 non-metallic rigid conduit

Some techniques on homebrewing yagi antennas by VK5AJL

W6CQZ JT65-HF project on sourceforge, the Amateur Radio software for reception/transmission of JT65A protocol with an emphasis upon its usage in the High Frequency Amateur Bands. Project is currently paused.

Battery-powered monitor designed to provide an audible indication of keying for those whose rigs lack a CW sidetone

A project for a vertical antenna for 60 to 20 meters by KV5R

A simple VHF quarter wave antenna from PL25

A stepper switch controller made with arduino by N3OX

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

A really simple project to make a power meter measuring RF output powers from a few mW up to half a watt. A DIY amateur radio project for QRP enthusiasts

A Picaxe Morse Code keyer project with source code and links to useful resources by K6ACJ

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.

Adding a 20m band pass filter for the Icom IC-706MkII(G) by ON7EQ

A home made project for an ATV RF power amplifier

Constructing a dip oscillator provides radio amateurs with a fundamental piece of test equipment for resonant circuit analysis. This particular design, adapted by VK3YE from a concept by _Drew Diamond VK3XU_, details a practical build using readily available components. The unit incorporates four plug-in coils, covering a frequency range from **2.6 MHz to 55 MHz**, mounted on 5-pin DIN plugs for versatility. A salvaged two-gang air dielectric variable capacitor, fitted with a vernier reduction drive, serves as the tuning mechanism, with the smaller gang optimizing bandspread at higher frequencies. In practical application, the dip oscillator is used by setting the meter needle to approximately two-thirds scale. When the instrument's coil is brought near a tuned circuit under test, a noticeable dip in the meter reading indicates resonance. This allows for precise measurement of resonant frequencies in antennas, filters, and other RF circuitry, proving invaluable for homebrewing and troubleshooting. The design emphasizes short wire runs for stable operation, particularly at the higher end of its operational range.

Interfacing the Jabra 9450 flex wireless headset to the Icom IC 7300 ham radio trasceiver.

Add bands to your Hustler xBTV Series Vertical

Band filters for PA6Z made by PA9M, designed by W3NQN.

A PTT switch from Home Depot parts

A great amateur radio shack desk done with a second hand solid core door, measuring 32 inches wide by 80 inches long.

13cms and 23cms ATV my projects and builds. Also using wifi amps on 13cms, 13cms dish feeds using a Sky dish. GB3CZ

Details on projects by WA3TFS published in QST magazine over the past few years. Includes an online shop with several ham radio kits, circuit boards, simple SDR transceivers

Modifications to an Ameritron ALS 600 power amplifier by AF6SA

A simple RF probe diagram

Repairing and restoring a Tektronix 465 oscilloscope

Pro and cons of Digital ATV versus Analogue ATV

A trapped multi band end-fed-half-wave antenna for 40/30/20/17/15m.

Make your own battery clip by nj2x

Pictures of the restructuring of the ham shack starting from an existing garage. Changes includes isolation of walls and roof and rebuilding of the radio table.

Build a 7 Element 4M (70MHz) Beam By Paul M1CCZ

A CW beacon keyer for 222 MHz by VA3NFA

The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a **LM34** temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise. This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a _TIP120 Darlington transistor_ to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments. Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.

A summary of common calling frequency for each digital mode on that band.

DTMF Keypad for radios without one. A project with picture and schematic diagrams to homemade a DTMF keppad

The purpose of this article is to provide radio amateurs with enough background information to understand the technical challenges involved in small-station digital EME on the 144 and 432 MHz bands.

A fully documented restoration project of a Hallicrafters SX99 receiver

A DIY aluminium push up mast project. The final mast includes 7 aluminium tubes with 6 cable clamps

A multi band antenna for HF band capable to operate from 10 to 80 meters band depending on wire lenght loaded with a small inductance neat the feed end.

Constructing a multi-band fan dipole for HF operation presents unique challenges, as VE2XIP demonstrates through his 2012 project to replace an existing commercial antenna. He details the process of calculating wire lengths using the 468/frequency formula, emphasizing the critical importance of equal leg lengths for each dipole element. The author shares practical insights gained from building at ground level, noting how elevation impacts resonant frequency and SWR, particularly for lower and higher bands. VE2XIP's experience highlights the iterative nature of antenna tuning, starting with the lowest frequency band (80m) and working upwards. He provides a specific example of trimming calculations and offers a clever tip for accurate wire removal. The article also touches on the mechanical aspects, such as dowel spacing for wire support and the benefits of a pulley system for repeated raising and lowering during the tuning process. Field results showed significant performance gains over the previous Alpha-Delta DX LB Plus, with **20 dB over 9** signal reports on 80m compared to 57. The project cost around **$100** for hardware, proving a cost-effective alternative. The author also discovered a bonus 6m capability and achieved an inverted-V _obtuse angle_ of approximately 115 degrees, contributing to a surprisingly stealthy installation.

Tutorial about writing a software SSTV modulator/demodulator using slant correction and several improvements. It requires programming language knowledge and programming skills.

The Shoddytenna is a 160 meters band vertical antenna intended for portable use. This antenna takes just 15 minutes to erect on site, can be carried by hand and is ideal for local groundwave work.

Tips and tricks for succesful soldering. An illustrated guide for beguinners and an usefull reminder for expert in soldering.

Use your Smartphone as an Oscilloscope to visialize signals from 150 Hz to 15kHz and as a Signal Generator to generate sinusoidal, square and triangular signals up to 15kHz

How to make a Morse Code Oscillator