How wide are these OTH radar signals. Do they blanket a big, big chunck of the HF spectrum, or do that seem to be more or less narrower? Have they been verified to be, in fact, OTH radar? Or could it be some kind of BPL?
Take a look at the image above your post, it will give you an idea of width. I have compared them to the recordings on the IARU website and they match the Chinese OTH Radar. Could be same type but another country.