Topband: ROKU 3 QRM

[Jim Brown]

On Thu,9/18/2014 12:41 PM, Dennis W0JX via Topband wrote:
> When I pulled the power on the relatively new ROKU 3, the noise level on the K3 dropped from S9 to S5, about 24 db!

RF noise is radiated by wires, in this case, the power supply wiring and 
the wiring between the Roku and your TV (and perhaps other wires 
connected to the TV). I have a Roku 3, and while I hear it in a TH-F6A 
with its loopstick an inch above the Roku box, I don't hear it in my 
antennas. I'm doing two things to make it quiet. First, I'm running it 
from a 12V battery that is floated by a small linear supply. (A year or 
so ago, I went through my home and got rid of all the switch-mode crap). 
Second, both the DC lead and the video cable have a multi-turn ferrite 
choke wound on Fair-Rite #31. It also helps that my antennas are at 
least 100 ft from the Roku 3.

73, Jim K9YC