[RFI] battery charger issue on 20m

[Jim Brown]

On 1/25/2013 6:15 PM, Greg Troxel wrote:
> Unplugging the charger silenced the noise.  Given that it seems coupled
> to AC wiring elsewhere, it seems pretty clear that this was conducted
> emissions.  What isn't clear yet is if it started on the DC side and was
> conducted to AC, or if it was generated in the charger.

You have just learned what many of us have known for decades -- ANY 
switching power supply is a likely source of severe RF noise trash 
unless it has been carefully designed to prevent it, it costs a few 
cents to do that, so they are all noise generators. Switching power 
supplies are almost universally used as battery chargers for everything 
from cell phones to power tools to mobility scooters, in wall wart power 
supplies, virtually all consumer equipment, appliances, for low voltage 
lighting, and so on. When we hear noise in our radios, it is more likely 
to be a switching power supply than a bad insulator on a power pole.

73, Jim K9YC