Friday 23 November 2012

A WSPR in your ear.

Like many of us, I am still amazed by the amount of radio spectrum we have to freely play with. Shots are being fired and eyes are being gouged by companies for small slices of precious bandwidth. Multiply our many electric playgrounds by the number of games (or modes) available and the permutations are enough to overload your front end.

I’ve decided to catch up with WSPR, a mode well known to many but new to me. I’m going to give it a go – the difficult way. Julian, G4ILO has an excellent article on the system here.

WSPR stands for Weak Signal Propagation Reporting and is a computer programme that runs your VHF/HF transceiver automatically in order to receive others running the same system. Successful contacts, one or two-way, are reported automatically to a website. It’s like having a worldwide net of propagation beacons for every band available at your fingertips and the results appear quickly after automatic contact confirmation. What a great thing to leave your equipment running overnight or during the day when you’re otherwise occupied!
Screenshot of Map Page

The best thing is that WSPR works below the noise threshold and you can use very low power. I was staggered the other day to see that Tim, G4VXE had hit Australia on 40m with just 1W! One Watt! So I’m going to give it a go with 1W and just an indoor Miracle Whip antenna. I know many QRP CW experts may cracked this one before – but I’m new and excited. I’ll try 40m and work my way up to 2m and see what happens!

I’ll use my FT-817. A CAT lead arrived this week from Hong Kong but it seems I’ll also need an audio interface between the transceiver packet port and computer sound card to make it all work. Another option is to buy an external interface that has a sound card and interfaces to the computer with a USB. It’s not quite going to be a ‘plug and play’ job, I’m afraid to report.

In the meantime, I’ll be satisfying myself to regular chats on 2m with nearby stations on FM, SSB and even DV mode. So many ways of talking – and that’s just on 2m. I'll 'whisper' my progress here as soon as I'm up and running.


  1. I have had the most radio fun in years with WSPR on 10m recently. 500mW to most of the States and beyond. On a bit of wire. As you say, the complicated bit is the computer interface. I haven't bothered with a CAT cable for the 817. Just a SignalLink interface, controlled by WSPR. An Elecraft T1 tuner, and Robert's your Relative.

    Mark, M0DEV

  2. Ha! Thanks Mark. Sounds great! Silly low power, silly short telescopic whip, 40m, 80m - 2m? It's going to be interesting.... 73, Rob.