6 December 2014

The Snake Charmer: a flute in HF


the signal has been spotted on 16927.0 KHz/USB from 1310 UTC, it's the so-called "snake charmer" here in the 16-step MFSK version. The transmission is likely sourced from HEB/WLO/WPG as reported in a detailed description reported here, although the author reports the 64 and 32 tones versions.
Below the 30 minutes long max-hold FFT spectrum that exhibits 16 tones, approximately 65 Hz spaced, in a range of 10 dB:

fig. 1 - max hold FFT spectrum

The signal is believed to be a test signal of some kind from WLO, WPG, or maybe HEB.  I just asked my friend MIke Chace-Ortiz (mco) and he replied that there have been 3 channels, all allocated to WPG active on 16MHz recently. The 22819.0 frequency (on USB) also remains active, usually with carrier from WLO direction but this also carries the same odd signal from time to time.