QRP Labs

Radio, Electronics and Computing Projects
by Hans Summers

I make no claims for technical accuracy, good design, or necessarily even originality for the contents of these pages. Rather, I am a simple enthusiast attempting to convey my love and enjoyment of radio, electronics, and computing and perhaps to inspire YOU to build something too. The following pages document projects that I have built over a period of 30 years. Wherever applicable I have named sources and references. In each project I have attempted to provide as much information as time and resources allow, but no responsibility can be accepted for inaccuracies or omissions. Likewise, where some of the projects use mains or high voltages, no responsibility can be accepted for death or injury sustained if you attempt to replicate these projects. BE CAREFUL! If you have any comments or suggestions, please email me.

Recent Projects:

Simple GPS Freq. Ref. PDF Print E-mail
Written by Hans Summers   
Thursday, 04 June 2015 03:03
GpsRef2 Here's a simple and easy single-chip 10.000000000MHz GPS-disciplined frequency reference, based on a small 14-pin AVR microcontroller ATtiny24. This implements a kind of software "Huff Puff" method stabilisation. It uses an old junkbox 10MHz OCXO. The final accuracy is about 0.5 parts per billion (ppb).
Last Updated on Monday, 10 October 2016 09:48
QRP Power meter PDF Print E-mail
Written by Hans Summers   
Wednesday, 21 January 2015 05:09
Weaver It's really simple to make a QRP power meter measuring RF output powers from a few mW up to half a watt. This simple project described here is half an hour's work and all components are from the junk box. I used an old "VU" meter from an old piece of consumer equipment, probably a 70's Hi Fi or something similar, long-since forgotten.
Last Updated on Wednesday, 20 May 2015 09:04
Weaver method SSB PDF Print E-mail
Written by Hans Summers   
Wednesday, 10 September 2014 03:26
Weaver The Weaver method (also called 3rd method) of Single Sideband reception is a little-used technique in HF receivers (except perhaps in Software Defined Radios architectures). This article is an introduction, some practical experiments with a 10m Weaver method receiver, and a collection of information on the subject.
Last Updated on Wednesday, 18 November 2015 05:12
OCXO and synthesiser design PDF Print E-mail
Written by Hans Summers   
Monday, 01 September 2014 10:30
OCXO This page documents the design and development of an OCXO and Synthesiser module. There were several motivations for developing this module, partly as a replacement for the popular AD9850 DDS module, available inexpensively on eBay and elsewhere.
Last Updated on Wednesday, 20 May 2015 09:09
Stable valve VFO PDF Print E-mail
Written by Hans Summers   
Saturday, 03 December 2011 13:35
VFO This is the story of my quest to build an all-tube VFO for 26.0 to 26.5MHz, for use in a 21MHz SSB/CW superhet transceiver with 5.0688MHz intermediate frequency (IF). Construction efforts below were assisted by advice and commentary by G4OEP, K3IMW, K7HKL and VK6JY.
Last Updated on Wednesday, 20 May 2015 09:13
Ultimate3S kit PDF Print E-mail
Written by Hans Summers   
Monday, 01 June 2015 03:49
U3S This is my implementation of the QRP Labs Ultimate3S QRSS/WSPR kit. My U3S is installed in the official QRP Labs case. I am using the relay-switched LPF kit for 6-band operation, and QRP Labs QLG1 GPS receiver module.
Last Updated on Sunday, 26 June 2016 09:47
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