Solar inverter or motor-drive noise
Noise from rooftop solar inverters and from variable-speed motors in heat pumps, pumps and appliances.
ModeSolar inverter or motor-drive noise
FamilyInterference
Audio exampleComing
What does it sound like?
Plate 60Interference
A buzz, whine or rough 'comb' of tones that comes and goes with the equipment.
Field marksOnly while the panels produce powerA comb of tones or a rough buzz
Who uses it?
Not a station: equipment in your home or nearby.
Where and when can I hear it?
Across shortwave; solar noise follows the daylight hours.
Easily confused with
- Switching power supply / LED noise: an ordinary power supply doesn't follow the sun