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This Arduino project decode ICOM CAT frequency information and switch antennas according to preset values. RX and TX antennas can even be different, a project by ON7EQ

An Antenna Rotator Project. The rotor design is based on sandwiching the gears and gear supports between two 5/16 inch 6061 T-6 aluminum plates

The page describes the construction of a simple omnidirectional, vertically-polarised dipole antenna for two metres using coaxial cable. It can be used indoors or outdoors, with no extravagant gain claims. The project is low-cost and can be completed in about 20 minutes.

Don't buy or build a semi-vertical trap antenna until you read this article! If you can use a drill, saw and screwdriver this is a simple project.

Build a 5 watt, 80 meter QRP CW Transceiver Designed by N1HFX

Run an oscilloscope under your Android phone

The 20m monoband 4-1000 amplifier, by Jelmer (pa5r), Herman (pa0ten) and Frans (pa5ca)

This program simulates a HF link, using sound card and WIN95 by Michael Keller, DL6iAK

6x2 coaxial remote antenna switch, completed unit showing weatherproof relay box and station control unit.

A short wave regenerative receiver project by Charles Kitchin, N1TEV

A homebrew fishing-rod vertical using a very nice design from EB5EKT. This antenna works 20, 30, and 40M bands by selecting the tap points using alligator clips

The Contesters Choice

The W6AMT Beacons is a Windows program which automates the collection of radio propagation data. HF data is collected by monitoring the worldwide network of NCDXF / IARU HF beacons.

This antenna allow transmission and reception on all bands between 7Mhz and 28 Mhz. Similar in concept to the Miracle Whip by VK3YE

A schematic design of the W3DZZ antenna in portugues with description of trap building

A low-level voltage meter and could even be used for audio purposes.

The project outlines the process for constructing a low-power FM broadcast transmitter using a Raspberry Pi Zero, a simple wire antenna, and battery power. It details the software installation steps for PiFM and MPG123, essential for generating and transmitting audio. The resource provides instructions for configuring the Raspberry Pi to broadcast FM signals, including command-line operations for initiating transmission and playing audio files. It specifically focuses on the Raspberry Pi Zero's capabilities for this application, highlighting its cost-effectiveness and minimal hardware requirements. The content presents a practical, hands-on approach to creating a basic FM transmitter, suitable for short-range, experimental broadcasting. It includes guidance on testing the FM output and ensuring proper operation of the software components. The project emphasizes the use of readily available components and open-source software to achieve functional RF output.

Build this simple and cheap 70 MHz Exciter and start to transmit Digital Television by Jean-Francois Fourcadier

UM58 a regenerative receiver project

An amateur observatory using a 4 GHz TVRO antenna.

1.2-30V 1.5A variable regulated power supply

A project to build a cross band repeater using a pair of Baofeng UV5R handheld transceivers.

Open source libraries and utilities to support using digital signatures for Amateur radio QSL system information like eqsl and lotw. Available for windows macos e linux.

A NorCal Project A Crappie, not crappy, portable antenna

A quick vertical for 160 meters portable use

Signalprocessing for SSB - Direct Conversion Receiver using Phasemethod for Sideband Supression, does all necessary signalprocessing for Direct conversion Receivers using IQ-mixer for demodulation.

The St. Louis Vertical Revisited by Dave Gauding, NF0R here are a few ideas and observations on the St. Louis Vertical

If your local repeater has got you singing the PL tone blues, then read on. For less than $10, an inexpensive PL tone generator can be constructed that will bring new life into that old non-PL rig.

Local and DX contacts from tight spaces, it works from 40 to 17 meters

Demonstrates the essential steps for winding **toroidal cores**, a fundamental skill for amateur radio operators engaged in homebrewing and kit building. It addresses the critical aspects of selecting the correct core material and wire gauge, emphasizing the importance of precise turn counting and consistent winding tension to ensure optimal circuit performance. The resource details methods for preparing the wire, including techniques for safely removing enamel insulation from leads using flame, sandpaper, or a solder pot, and provides guidance on tinning the exposed wire. Explains the process of mounting the wound toroid onto a printed circuit board, highlighting the need for careful lead placement and secure soldering to prevent shorts and ensure mechanical stability. It also offers a practical formula for calculating the required wire length based on the desired number of turns and the specific **toroid** size, referencing common core types like T-50 and FT-240. The guide stresses the importance of verifying the inductance of the wound component, often using an inductance meter, to confirm it matches design specifications. Provides practical tips for handling multi-filar windings and managing short lead lengths, which can be particularly challenging. It underscores the necessity of meticulous attention to detail throughout the winding and installation process to achieve reliable and efficient RF circuits.

Online map creation using AZ_PROJ

Circuit diagrams to homebrew different baluns by vk2awx

A two element multiband quad antenna

80 metre ceramic resonator VXO CW Transmitter by VK1PK

Build an HF antenna tuner by VK5AJL

Yet another G5RV antenna plan to build a G5RV Antenna for 80 to 10 meters usage

Recordings of shortwave numbers stations

Excellent poster representing the electromagnetic spectrum from 31.2 mHz to 6.52 EHz, PDF file poster designed by Anthony Tekatch

Remotely controlled antenna switch that can switch between 5 antennas

A pdf file with schematics of an ssb and cw filter AF amplifier

Build An Offset Attenuator by Joe Moell K0OV as featured in Homing In for May 1998

Spek helps to analyse your audio files by showing their spectrogram. Spek supports all popular lossy and lossless audio file formats. Spek is free software available for Unix, Windows and Mac OS X.

A simple circuit which will generate a 700 Hz tone into any FM transceiver allowing an amateur to practice CW with another amateur on a 2 meter simplex frequency.

This vertical antenna consist of a 18 meters telescopic pole and allow operations from 160 to 30 meters band, project by Daniel Zimmerman N3OX

For radio amateurs seeking compact and efficient antenna solutions, particularly for restricted spaces or noise reduction, HF loop antennas present a viable option. This resource compiles several articles from the ARRL, detailing the theory, design considerations, and practical construction of various loop configurations. Topics include small transmitting loops, receiving loops, and multi-band designs, often emphasizing their performance characteristics such as directivity, bandwidth, and impedance matching. The collected articles provide insights into the comparative performance of different loop geometries, such as circular versus square loops, and discuss the impact of conductor size and tuning methods on efficiency. Practical applications are explored, including their use in portable operations, stealth installations, and urban environments where noise mitigation is critical. The content often includes construction diagrams, parts lists, and performance data derived from modeling or field tests, enabling hams to replicate or adapt the designs for their specific operating conditions.

Contains digimodes, antenna projects, DX info and lots more

KG4JJH moxon assembly plan for the 50 Mhz in a pdf file

This strange looking antenna is a combination of Coupled-Resonator principle by K9AY and a quarter stubs to achieve low angle radiation pattern. Designed with 4nec2 NEC based antenna modeler and optimizer for 145/220/440MHz bands

A 144/440 dual band open stub J-Pole Antenna project by NT1K