Over-the-Horizon Radar Systems are Back on HF

 

The International Amateur Radio Union's Region 1 Monitoring Service is reporting significant interference on HF ham bands from over-the-horizon (OTH) radar systems believed to originate in China and Russia. According to the IARU, the 10-kHz-wide signals of the so-called "foghorn" radar from China have been heard on 40 meters, particularly in the 7113-7123 kHz and 7165-7175 kHz ranges, and on 20 meters as well. In addition, the Russian "contayner" OTH radar system has been monitored on 20. The monitoring service urges amateurs suffering interference from these signals to file complaints with their national regulatory agencies.