These pages and articles provide supporting material to the RSGB
series of articles on the CDG2000 transceiver. The aim is to provide the
reader with the supporting text to the series either to explore issues in
more depth or to provide additional material such as user guides,
software, pcb artwork and performance data. It will be extended as the
series progresses in RadCom.
All materials provided here are copyright Dave Roberts G8KBB, George Fare G3OGQ and Colin Horrabin G3SBI. In all cases, materials are provided for the purpose of self education and training in Amateur Radio. No use may be made for commercial purposes without permission of the authors. PCBs and some components are available from the authors.
Calibrated Noise Source
A noise source is a useful piece of test equipment used in the measurement of noise figures within receivers. This article describes a circuit diagram and PCB layout that can be used to construct one.
Advanced DSP and PIC (WARCPIC)
A club project designed by Dave Roberts, G8KBB, and
George Fare, G3OGQ.
Digital signal processing techniques are becoming the norm in radio rather than the exception and this article serves as an introduction to audio DSP for the home constructor.
160m AM Receiver
Single Side Band (SSB) is now the main voice communication mode
on the HF bands although AM is making a bit of a return with a
number of amateurs rejunvinating old equipment and putting it
back on air. There are a number of nets on 80m and 160m (Top
Band) that meet to put this old equipment through its paces.
In this article George Fare, G3OGQ, describes an AM superhet receiver that will cover the whole of top band.
Digital Power Meter
A power meter is an essential piece of test equipment in every Amateur's shack. This award winning design by Dave Roberts, G8KBB, describes the construction of a digital power meter with good accuracy and an operating range from 100kHz to 500MHz.
It is often useful to be able to simultaneously connect more than one pair of headphones to a rig. A simple buffer and audio amplifier circuit is described here with additional commentary on creating your own printed circuit boards (PCBs) from scratch. Ian White, M0BXR, describes the construction using the ubiquitous TBA820M audio amplifier IC.
13.8 Volt 20 Amp PSU
Most modern rigs are designed to run from an external 13.8 Volt Power Supply Unit (PSU) and for high transmitted power levels a stable, high output current supply is required. This PSU design is repeated and updated from the original 1987 article in Amateur Radio magazine by Steven Goodier, G4KUB, and John Goodier, G4KUC and is capable of supplying 20 Amps.
Crystal Filter Design
Designing crystal ladder filters may seem like a daunting task but Jack, G3JIR, has written a number of articles to guide you through the process. Horst, DJ6EV, has also produced a program for Windows to assist in the number crunching and allow anyone who isn't a mathematical whizz to design their own filters.
Near Space Project
Amateur Radio is a self-teaching hobby in the art of radio communications and when all the terrestrial modes have been tried, where else can you turn but to the extra terrestrial? As well as the fun element, there is a lot of education and learning to be had from a project to launch a radio payload to the edge of space, track it and recover it after its return to earth and that is what WARC's Near Space Project is all about.