Database of interference sounds and devices


In each case click the graphic to hear a sample of the QRM


BT Vision Powerline adaptor 3-30mhz notched in some ham bands reported range 500 yards. UPA Type (Universal Powerline Association)

Advent HPA (Home Plug Power Alliance) type powerline adaptors as sold by PC World, range three houses click pop when idle, louder and faster when in use. 2-22mhz no notches noted.

SavaPlug from Iceland and other stores, reduces power consumption of fridge freezers quite old tech now, QRM from 240khz to 600Khz some harmonics also. (in house)

Defective street light (not as shown) QRM 100 kHz to over 32 MHz 200 meters range


Mains powered (12vdc)ultrasonic cat deterrent, very local cure by adding earth spike to negative wire. Frequency range 10-30 Mhz


Alba TV/DVD on standby affects 9- 11 Mhz range 100 feet, cured!

Cure with TVI Filter as shown Fits between TV and antenna.


Electric fence, range 400 yards worse at night. The sound clip was made at 400 yard range, close up its a very clear noise. Cure by asking owner to check connections for rust and to make sure weeds have not grown into it. Point out fence will work better as well! Cured!


Go back to main page