Looked at a RF spectrum that came from the IF output on a radio so it was not tuned thru the radio filters, just whatever the HF antenna was capable of. A pulse went across the entire spectrum slow enough to see it sweep across the screen. The pulses were not regularly spaced but came in bursts on average prolly 1 every 30 seconds. Lots if people in my circle know it. The hypothesis is Chinese OTHR, purpose unknown. How can one identify such a thing. I can video the computer screen this Friday if that helps.