Over-the-Horizon Radars Continue to Plague Amateur Bands

The International Amateur Radio Union Region 1 Monitoring System (IARUMS) reports a “new kind” of over-the-horizon (OTH) radar on 20 meters. The intruding signal, which appears to be emanating from the Far East, was monitored during May on 14.140 – 14.150 MHz. Another Chinese wideband OTH radar has been showing up on 15 meters, with a signal 160 kHz wide. An Iranian radar has appeared on 10 meters, centered on 28.860 MHz, and is audible in Europe during sporadic-E conditions. The signal is about 46 kHz wide. The Russian OTH radar “Konteyner” OTH radar centered on 14.127 MHz continues to be observed, with a 12 kHz wide signal.

The so-called “Foghorn” OTH radar from China, first heard in 2017, and other OTH radars were spotted on several 20-meter frequencies. The Foghorn is a burst radar that has been heard on other bands, with the signal often jumping. The signal is frequency modulation on pulse (FMOP) with 66.66 sweeps-per-second bursts.

From the Commonwealth of Independent States (CIS) that emerged following the breakup of the Soviet Union, taxi traffic continues to appear on 10 meters, using FM. IARUMS said pirates in the Far East have been “abusing” 20 meters, transmitting on 14.000 MHz, using USB. IARUMS monitors also logged several fish net (driftnet) buoys between 28.000 and 28.500 MHz, transmitting a carrier followed by a CW identification. Codan selective callings (selcalls) believed to be in Oceania have been heard between 7.108 and 7.150 MHz

Source: ARRL