Sources of RF interference in my home

[kb2vxa]

Well Vern (in my best Jim Varney impersonation) I had a similar experience being bracketed by touch control lamps. One neighbor traded for a look alike with a standard switch, I stomped the touch lamp to death. The other was obstinate even with the FCC so when I found the frequencies that activated them their house lit up like Frankenstein's lab in time to the CW dits and dahs. A long CQ usually killed the noise when they unplugged the lamps.

 

[comsec1]

invisible dog fence

I had a person who lived next door that had an invisible dog fence made by a company called INNOTEK. it wiped out everything up to 7-8 mhz including the AM broadcast band, I offered to buy him a new one that did not interfere and also paid for all types of filters, he still refused to acknowledge that was problem even though the power company told him it was. He started receiving letters from the FCC explaining what harmful interference was and what to do about it and to turn the device off. well he still acted very obstinate about it and never responded to the FCC. then one day the thing was turned off and there was a for sale sign on their lawn.

 

[Emoney250]

mobile scanner interference

I use a mobile scanner (PRO 196?) in my work trucks. I simply set it on top of the dash and hook up the Radio Shack magnetic mount long antannae. Problem: I get scanner "noise" on different frequencies (pre programmed in my scanner that I use daily) depending on which of the 8 trucks I use. I wonder if there is an easy way to shield the scanner from the RF interference coming from the trucks.

Eric

thanks

 

[ka3jjz]

OT post - this forum is for topics below 30 mhz. Please take your question to the forum linked below.

General Scanning Forum - The RadioReference.com Forums

Thanks for your future cooperation best regards and HH Mike

 

[AC9BX]

Like mtindor mentioned the ethernet router, these things are among the worst offenders. They often have cheapy switching power supplies. Then you attach several tens of feet of unshielded twisted pair to them, connected to computers. It's a recipe for failure. I've seen ethernet systems radiate at numerous frequencies in the HF band wiping out several MHz at once over a city block.

 

[mitaux8030]

Anything with a switchmode power supply has ripe potential to cause interference.
Worst offender here is a DVD player - turned on it generates an angry buzzing sound that is audible on freqs from LF to VHF. It radiates via the power lead very strongly, so much so that a medical grade mains filter does little to abating the noise. Its going to get the sidecutter treatment through some vital internal cable in its near future; "whats wrong with the DVD?" "Dunno hun, its so cheap, not worth fixing, we will just buys another"
The other big noise source is the plasma TV. Nothing that can be done about it, all the noise radiates from the screen itself. I can hear it from darn near 30 feet away on the truck AM radio.
I did remove another source of noise here recently: a standard fluroescent tube. Simply replacing it with a brand new one reduced S9 noise down to S0 and barely audible. I refuse to use those CFL bulbs except for areas that don't often need the lights on, I found them to be a big problem, even the expensive name brand types.
Cell phone chargers are noisy too, but I charge mine in the truck mostly, and a ferrite on the ladys cell charger works a treat.
New breed of direct drive front loader washer also fills the spectrum with weak whinig sounds, but since its use is itinerant, I can live with that.

The worst offender I've seen by far was a faulty TV switch mode supply. One day it was fine, the next it was sending absolutely huge amounts of noise onto the mains line - but still powering the TV just fine thanks, so the owners saw no reason to replace it. Never mind that the WHOLE BLOCK of houses couldn't listen to AM or any form of shortwave or CB radio. Could hear this one down the road a good 500 feet away in the truck. Solved this one by the most drastic of solutions: moved house. Suppose I could have bought them a new TV... nah, not that generous.