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

6dB Better than CW Weak signal modes and how they work. A updated version of the presentation given at the RSGB Convention 2012

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

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(Some hardware details are a bit are out of date now)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

21st_Century_Radios Presentation at Martlesham Microwave Roundtable April 2012

Modern Synthesizers Presentation at RSGB Convention, 12 October 2014

137 and 475kHz, The Experimenters' Bands Presention first given to Itchen Valley Club March 2016

Third Method Upconverter for LF/MF Presentation at RSGB Convention October 2017

Sites, Heights and Locators. Presentation at Crawley Microwave Roundtable Sept 2018

24GHz Beacon using Direct I/Q Upconversion.Presentation at Crawley Microwave Roundtable Sept 2019

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

Problems often Encountered with USB Soundcards on a PC

10GHz PLL Low Noise Block phase noise tests on a new generation LNB suited to narrow band modes
First published in Scatterpoint April 2013

SMT Hell at 137kHz 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 , JT4 , JT9 and and ISCAT Coding Processes
Wolf Coding Process Weak Signal mode based around strong error corrected BPSK

Position Reporting using WSJT Modes Using Weak signal modes to transmit high resolution positional data. Lat/long from GPS data is compressed into a WSJT compatible message and sent using JT4 or JT9 modulation. This article appeared in RadCom Plus September 2015

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

KST2ME Primer for Microwave Talkback