Software Defined Radios

What is an SDR?

SDR stands for Software Defined Radio. Commonly, this relates to a piece of radio hardware that controlled via a computer.

On this page, you’ll find some information on SDRs, and our team’s experiences of ham radio and SDRs…

80 Metre SDR Kits

Many thanks to David Ingrey M0HBV for the loan of his SDR, featured here. David constructed this nifty SDR himself from a kit. It’s the G0NQE Acorn SDR, available at the time of writing for £19.95 from www.kanga-products.co.uk.  The Acorn SDR is a single sideband receiver, and once built, will cover the 80 metre band (3.5MHz).

This kit uses standard components (as opposed to surface-mount devices), making it fairly easy to construct for those handy with a soldering iron. Here’s a photo of David’s fully-populated board:

The kit has a 3.5mm audio output, which you’ll need to connect to the microphone input on a PC. With suitable software, the PC then handles the audio from the Acorn and allows you to see what’s happening and tune into QSOs on the 80 metre band.

There are several free SDR applications out there, and I had a play with two. First off, M0KGK’s SDR package (from www.m0kgk.co.uk), which did a great job of handling the audio from the Acorn. Here’s a screenshot showing the 80 metre band with the soundcard set to handle 96kHz

I also had a try with Winrad, which has a slightly more complex interface, but does give you a few extra settings to twiddle and a few more controls to analyse the incoming audio. The ‘waterfall’ view will be familiar to Ham Radio Deluxe / PSK31 users, and makes spotting a strong signal very easy. Winrad, by  Jeffrey Pawlan WA6KBL, is available from www.winrad.org

Thanks again to David M0HBV for the loan of this excellent low-priced SDR kit.