Publications

Weak signal modes on the Microwave and 3400 MHz Bands Presentation at Martlesham Microwave Roundtable 2009 -

Using GPS in Amateur Radio
How GPS derived timing can be used for new data modes and for accurate frequency control.
This article first appeared in Radio Communication April 2006

GPSRadiotalk
Presentation given at the RSGB HF Convention October 2005

Software Defined Radio The basics behind SDR techniques.
A presentation given at the HF Convention in 2002
(Some hardware details are a bit are out of date now)

Using PICs in Am Radio Presentation at Finningley Microwave Roundtable July 2011

SDR-IQ Linearity Tests
A short note describing the results of some two and three tone measurements on the RF Space SDR-IQ wideband digital receiver. Alhough only a quick and simple measurement, they show clearly that the concept of Third Order Intermodulation Product (TOIP) applied to wideband receivers is completely flawed.

Several good articles on SDRs, I/Q processing and DSP can be found on the links page

Amateur Use of Novel Signalling Methods at Low Frequencies
A poster presented at The IEE Conference, London on 24/25 October 2002 entitled "Getting the Most out of the Radio Spectrum"

The WSPR and JT4 Coding Processes

WSPR S/N Test Results Too low a receiver bandwidth gives false reported S/N values.

Index to RadCom Data columns
Index to RadCom Design Notes and Short Circuits columns

List of Maximal Length Shift Register taps
Really ought to credit someone with this, but can't remember where it came from, or find the URL