Whenever 12m is open toward Europe, KH2L and I always hear this ticking noise. It really is annoying and makes weak signal copying difficult. The K3 does a so-so job of cleaning it up.
It’s probably some sort of OTH radar out of China, but I’m not certain. It is definitely DX however. Just another example of the garbage on the bands out this way.
Apparently this is a CODAR ocean wave radar for measuring sea state and currents. They are deployed all around the coast of China, Taiwan, South Korean, and Japan. They are capable of operating on 24Mhz.