Power-line noise
Electrical noise from power lines and pole hardware, usually from loose or worn parts making tiny sparks.
ModePower-line noise
FamilyInterference
Audio exampleComing
What does it sound like?
Plate 50Interference
A harsh, raspy buzz, often with a 120-times-a-second rhythm (100 in 50 Hz countries), or crackling.
Field marksA buzz at 120 pulses a second (100 in 50 Hz countries)Often worse in dry, windy weatherSpread across many frequencies
Who uses it?
Not a station: electric utility equipment.
Where and when can I hear it?
Worst on the lower shortwave and AM bands; often worse in dry weather and near the faulty pole.
Easily confused with
- Electric fence ticks: a fence pops about once a second instead of buzzing
- TV or display buzz: TV buzz stops when the screen is switched off