Wednesday, February 10, 2021

Ongoing HF QRM from Radars and Others


The International Amateur Radio Union's Region 1 Monitoring Service reports increasing levels of interference on HF ham bands from over-the-horizon radar (OTH-R) systems as well as fishing buoys and international broadcasters. 

According to the ARRL Letter, Russian and Chinese radar systems are now showing up on 17 and 15 meters as well as 20, where they have long been a problem. In addition, several international broadcasters have popped up below 7200 kHz on 40 meters, which is supposed to be exclusively amateur under International Telecommunication Union rules. Finally, the improving propagation on 10 meters resulting from the startup of Solar Cycle 25 is revealing the ongoing presence of fishing buoys on the band, long a nuisance but not recently a problem due to poor band conditions.