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A simple accurate power splitter for the 70cm uplink to Oscar 13

A simple TRAP-dipole project for 20 and 40m bands includes EZNec simulations

Introduction to IRLP

A ground plane antenna for 80 meters band

An interesting home made project of an L Network Antenna Tuner Project with pictures and schematics by K7SFN

An Arduino APRS project based on the real time OS BeRTOS

14MHz SSB 10mW transceiver by JF1OZL

Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

A lower power desktop linear with integrated 120vac power supply. This, very compact, dual 811 version will deliver about 300 watts output. Covers all bands including WARC bands.

N1HFX article on adjustable voltage regulator

Long Range Wi Fi Antenna by AB9IL

Some rules of thumb for beginners, with a QRP approach, by James R. Duffey KK6MC/5

A Lindenblad Antenna for 145 MHz and 435 MHz with an integrated 50 MHz J-pole

Paddles made from readily available materials, like double sided PC board material and cost almost nothing to build.

The Collins TRC-75 autotune linear amplifier, owned by JF2SVU, is presented with a focus on its internal modifications. This QRO amplifier utilizes three 4CX250 tubes in parallel for its final stage, delivering 1 KW output power. Notably, the amplifier achieves full power with only 100 mW of RF input, a characteristic often associated with Collins designs. The original 400 Hz power supply has been converted for easier shack integration, and the entire RF and power supply sections have been rehoused into a compact, clean enclosure. The control unit, positioned above the amplifier, features three meters for individual vacuum tube IP monitoring and a multi-meter on the right. A dedicated 7 MHz receiver, recently completed, is also part of this integrated system. The autotune functionality means the main amplifier unit only requires connections for power, control, and coaxial cables, simplifying its operation. Key components like the 4CX250 tubes and NF capacitors are visible, along with the gearing mechanism for the final tank circuit. A timer and relay system manages high-voltage delay and cooling fan off-delay, although the cooling fan's airflow is noted as somewhat insufficient. A central volume control, which experienced a contact issue, is also highlighted.

136kHz portable station project by PA4VHF Dick

This is a design for a stealthy HF multi-band vertical wire antenna using a tree as a supportby G7AQK

Build An Inexpensive Repeater Controller from a Basic Stamp 1 or 2 By Roger Cameron

This article document a 2 element half wave collinear J-Pole antenna by KC9EOT and KB8OJH

Tips and tricks on homebrewing your own Coax traps by ON7EQ

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

This homemade tube oscilloscope is based on the WaterMan Pocket-Scope 0510A, a 3 tube oscilloscope made in 1946.

A New Twist on Portable Multiband HF Dipoles, a Multi-band Spiral Dipole Off-Center-Feed match (OCF) antenna solution.

Displays the actual transmitting beacons of the NCDXF/IARU Beacon Project.

Digital Voice Transceiver Project This Project began to explore the use of the DVSI AMBE 2020 voice compression chip and also the ADF7021 single chip VHF RF Transceiver from Analog Devices.

This article explain how to homebrew and use an HF antenna analyzer by simply adapting a Windows PC, micro-controller and a DDS evaluation board by K6BEZ

The digital wattmeter project was created for the purpose of measuring power in the range of 300nw to 30w.

A controller for the miniVNA using an Arduino UNO and touch screen color graphic LCD display

Rotator controller, azimuth & elevation control of rotators (automatic antenna turning) based on commands from computer. A project by Pavel VACHAL and OK1DX - KF9VM

Key your transmitter from the tone output of a Morse Code generator program

This antenna analyzer measures complex impedance over the 1.6 - 33 MHz HF spectrum

Lot of useful information on experiments on 136 Khz band, with antenna tips DSP infos and notes on their activity in LF.

Interesting article on multiband fan dipoles. This article give an overview on designing this wire antenna, and planning a robust installation and proper feed line. Includes notes on setting up a commercial fan dipole antenna and on how diy your own.

A complete guide to Baluns and transformers by WK5AJL

DIY voice keyer for your next ham radio contest. An interesting homebew voice keyer project by ON7EQ

A project for a SDR receiver by Juan Domenech Fernandez

W3EDP antenna assembly instructions and dimensions with pictures in this PDF File

Have you problem with your RG cables ? This page describes a smart antenna box using an RG-cathode for 3 antennas. The remote control needs just a simple wire and the GND for remote-control

A four element 2 meter quad antenna project

A remotely tuned 80m to 10m wire vertical antenna

The NCDXF/IARU International Beacon Project operates a worldwide network of 18 high-frequency radio beacons, continuously transmitting on 14.100, 18.110, 21.150, 24.930, and 28.200 MHz. These beacons, initially launched in 1979 with a single station and expanded to the current 18-beacon system in 1995, provide reliable signals for both amateur and commercial users to assess current **ionospheric propagation** conditions. The system's design, construction, and operation are managed by volunteers, covering hardware and shipping costs. The resource details the evolution of the beacon network, including the transition from Kenwood TS-50s transmitters to Icom IC-7200 radios with a new controller design implemented in 2015. It explains how listening for these 100-watt signals, transmitted to vertical antennas, allows operators to determine band openings and optimal propagation paths globally. The content also references three QST articles providing historical context and technical specifics of the beacon project. Practical information includes methods for identifying transmitting beacons via a schedule or specialized software like FAROS and Skimmer, which integrates with the **Reverse Beacon Network** for automated monitoring.

Schematic anc PCB for a fox hunting receiver for 80 meters band

Amateur Radio Projects & Kits for homebrewers, includes DDS,sound card interface,programmers, hamcom, frequency counter, RF Power Meter, modems and more.

How to build a lightweight amplifier that can be backpacked around.

VK3YE magnetic loop antenna plan that cover 7 Mhz to 20 Mhz and shortening loop can work on 21 Mhz.

Tips to homebrew your own HF traps using aluminium wire and doorknob capacitor

High Gain Wi-fi Helical Antenna by AB9IL

This simple and cost effective interface circuit is designed for use with any ICOM amateur radio equipment with CIV interface

Home brewed spider beam by VA7ST

The page provides a project for an helical dipole for the 40 meters band, resonating on 7 MHz, created by PY1ZFK based on a design by DL8VO. It includes detailed instructions on building the antenna.