The video clip below provides a Spectrum Analyzer view of broadband noise spanning the HF, VHF, and UHF bands.
It starts out focused on the hi-band VHF channels 7 thru 9, but will eventually broaden the view to span frequencies from 2MHz through 700MHz. The effect of the noise on reception, during periods of least margin, is a fairly repetitive pattern of bursts of pixellation.
Click the play button to start.
There is another brief example here.
A keg to the first person who can provide a clue that leads to positive identification of the source!