[Elecraft] LCD TV Causing RFI

[Jim Brown]

On 1/30/2011 3:19 PM, Brian - N5BCN wrote:
> There are only two wires connected to each TV: A/C power and a HDMI cable to
> the DVR (cable is plugged into the DVR, not the TV).  The DVR is always "on"
> to record show when the TV is off.
>
> With the TV on, I unplugged the HDMI cable and viola!, no RFI.  So, it seems
> the noise is emanating form the HDMI cable, either being generated by the TV
> or the DVR, but ONLY WHEN the TV is on!

You left out what may be the most important cable(s)  -- the coax that 
provides the RF signal to these sets (and/or a CATV box or DVR).  That 
cable can also be the antenna, and the HDMI cable may simply be coupling 
the RFI from the set to that coax.   Now, a choke on that HDMI cable may 
solve the problem, but don't forget that the coax is there, and could be 
radiating other lower level trash from those other boxes that you 
haven't identified.

73, Jim K9YC