On 1/29/2011 9:40 PM, Brian - N5BCN wrote: > The offending TV is not close to the shack: TV is on the first floor, shack > on the second floor (on the opposite side of the house), antenna in the > attic.
REPEAT AFTER ME -- IT DOESN'T MATTER WHERE THE SHACK IS, IT'S THE ANTENNAS! Whatever trash the TV is generating is conducted from the TV to the CABLES that are connected to it -- power, antenna (or CATV), DVR, audio -- and RADIATED by those cables to your ham ANTENNAS. It can also be radiated directly from wiring inside the TV if it is poorly shielded, or poorly designed. > The TV is using cable with a DVR. RF trash radiated by the CABLES can be killed by winding multiple turns of each cable through it's own #31 ferrite core. Ferrite cores come in many sizes to fit cables of various sizes, and to allow the needed number of turns. You'll need about 5 turns through a core to optimize the suppression on 20M, and that suppression will be pretty effective from at least 40M up to 10M. The #31 material is made only by Fair-Rite, an excellent US company that makes the vast majority of ferrite materials used by hams. For a tutorial discussion of all this, and specific recommendations for parts to buy and how to wind the chokes, see http://audiosystemsgroup.com/RFI-Ham.pdf FWIW -- it is VERY rare for LCD TVs to cause RFI to ham gear, and the major Korean brands have a pretty good reputation in that regard. This is only the second report I've seen, and RFI is one of my specialties. :) Please let us know the exact model number so that we can post it to the RFI email reflector. 73, Jim Brown K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
