The OTH radar noise has started ruining 40m very badly. It is told to come from somewhere in the south easetern China. the Wikipedia tells it is originally on 1.8MHz causing spurious disturbance on 7MHz. It seems to be a frequency sweeping system, which is new to me, different from the former ones. The conventional noise blanker is of little use for this noisy splatter.
The OTH radar systems have been researched and utilized by a number of nations for guarding themselves since the end of WWII. The accuracy as radar seems not very high. But it may be useful, so far as the military officials judge, for observation of invaders to their countries. While they are always trying to overcome such system, they are still keeping building such system. It seems like a tragecomedy or, more likelily, a smell of military industries playing a drama which they have written by themselves.
If this splattering on the amateur band is due to the OTH radar by China, they are acting against IARU. IARU should promptly protest against their behaviour. We should write to the embassy or the consulate of China to stop it or they will be regarded as one of the invading nations by all amateur hams in the world.
I quit operating 40m at night as I have been doing here and decided to spend time for the other things. China may be helpful to me to use the precious time in this way.