What causes interference received as a series of carriers at regular intervals across a wide frequency range?
Switch-mode power supplies✓Bonne réponse
Radar transmitters
Wireless security camera transmitters
Electric fences
Explication
A switch-mode supply chops its input at a fixed rate with fast edges, so its noise spectrum is a comb of harmonics of the switching frequency, heard as evenly spaced carriers repeating across a wide range. Radar, wireless cameras and electric fences each produce quite different signatures.