Strange Signals and Mysterious Oscillations

The IARU-R1 Monitoring System newsletter reports mysterious oscillations on 28000 kHz and strange signals from Central Africa

The International Amateur Radio Union Monitoring System (IARUMS) Region 1 June 2017 newsletter - http://www.iarums-r1.org/iarums/news2017/news1706.pdf

Reports of Amateur Band intruders can be logged on the IARU Region 1 Monitoring System Logger - http://peditio.net/intruder/bluechat.cgi

Monitor the short wave bands on-line with a web based SDR receiver - http://www.websdr.org/