Switching power supply / LED noise
Noise from phone chargers, LED bulbs, power adapters and other modern electronics.
ModeSwitching power supply / LED noise
FamilyInterference
Audio exampleComing
What does it sound like?
Plate 64Interference
A whine, buzz or rough carrier that may drift, repeating every few kHz as you tune.
Field marksRepeats every few kHz across the bandCan drift as the device warms up
Who uses it?
Not a station: devices in your home or nearby.
Where and when can I hear it?
Anywhere on shortwave; often a 'picket fence' of signals at regular spacing across the dial.
Easily confused with
- Steady carrier: a real carrier doesn't repeat every few kHz