SM 5 BSZ - The 137kHz qrss test data.
(July 27 2003)
At low frequencies amateur signals are very weak. Amateurs use ordinary morse code to communicate at very poor S/N ratios. The morse code bit may be up to 120 seconds and the keying is decoded visually on a waterfall diagram.

To get some input for the development of a qrss mode in Linrad I have made a test recording on 137 kHz with some amateur qrss signals present in it. The date was June 17 2003, approximately 22.25 to 23.00 UTC. The antenna was a single turn rectangular coil with side lengths 2 x 4 meters. The long wires were horizontal and the coil center 5 meters above ground. The coil was oriented with its zero direction SE - NW.

The file is about 1.2 gigabytes and contains several different types of interference on top of the amateur generated signals.