OUTDOOR CAM: electronic noise when plugged in

Installed an outdoor cam on the front of our house.  Worked totally fine, but with all of the activity - the battery doesn't last as long as we'd like.  Ordered the Outdoor Camera Power Cable - but am now getting an electronic interference noise.  NOTE: this noise is not the wind, and is not present when the camera is not plugged in - it appears to be completely electronic noise coming from the unit while plugged in.

It is NOT the buzzing sounds in some of the other recent posts, and the camera audio works fine (although the electronic noise continues).

Anyone had this issue before?  Is it known?