QRSS stands for (very) slow speed CW. I got interested in QRSS after seeing a presentation on it at the 2003 Austin Summerfest. QRSS signals typically use 3 - 30 second dot lengths and very low power -- 100 mW and down. It's pretty amazing to copy a 5 mW signal from hundreds or thousands of miles away; a very effective demonstration of the ability to trade communications rate for power.

How to listen to QRSS

QRSS signals are typically monitored using a radio connected to a soundcard running a program such as Argo. The program takes the audio and displays it in a slow moving waterfall. As a QRSS message can take a bit of time to arrive, Argo can be set to save the waterfall to images as they arrive. It also also has various settings for sensitivity, contrast, and gain to make it easier to fish a low power QRSS signal from the noise.

Where to listen for QRSS

The QRSS signal's I've copied have been either 10Mhz amateur radio signals, or part 15 "Hifer" signals around 13 MHz. Longwave Club of America has a good list of LowFer, MedFer and HiFer stations. The Knights QRSS group has a list of frequencies and other good information on their site as well. They also run a mailing list which is good for knowing when a QRSS station will be on the air.

10 mW from NC to TX

The images below show my copy of a 10mW QRSS 30 signal from AA4XX near Raleigh NC. The message being sent was callsign followed by a 3 letter codeword repeated 5 times. Each screen shot covers about 28 minutes, so it took about an hour to receive the message.

This signal appears to be wavering quite a bit. That's actually not the case. The vertical span of the image only covers 6 Hz; the wavering of the signal is only about 1.5 Hz. Part of that is probably the receiving radio coming up to temperature, and part of it is probably a propagation artifact.


Date (UTC) Station Frequency Power Location Mode Comments
29 Aug 2004 22:53 VDO 13.554991 MHz 10 mW/3 mw ERP Austin, TX QRSS3 1st SDR 1000 QRSS
7 May 2004 01:00 AA4XX 10.140130 MHz 5 mW Raleigh, NC QRSS30 Solid signal
5 May 2004 01:00? AA4XX 10.140130 MHz 10 mW Raleigh, NC QRSS30 Wavey propagation
28 March 2004 NC HiFer 13.555430 MHz 2 mW NC EM95 Sq Wave http://www.w4dex.com/HiFer.htm Argo Screen
5 October 2003 AA4XX 10.140130 MHz 50 mW Raleigh, NC QRSS10  
4 October 2003 AA4XX 10.140130 MHz 100 mW Raleigh, NC QRSS10  

This log is somewhat incomplete as I did not keep the best of records early on playing with QRSS signals.

Comments to: Bill Tracey (kd5tfd@ewjt.com)

Last Updated: 30 Aug 2004

Copyright © Bill Tracey 2004