I have just witnessed the strangest thing, listening on 7160 to the WAB (Worked All Britain) net when a load of 5/9+ PSK signals just appeared on the frequency, and then a few seconds later went away.
This happened a few times, it wasnt just a rogue station, at first I thought it was someone fooling around, but no when I checked the waterfall, it was numerous signals.
Here is a screenshot of PSK reporter, hopefully you can see my call and the frequency, and the stations recieved, just click on it to enlarge.
UPDATE - This was really so strange that I ran downstairs and picked up a camera and made a video, hopefully it shows what I am trying to say, please I would dearly love some comment on this.