On 5/10/2011 7:49 PM, Jim Wiley wrote: > You guys are aware, I suppose, that interference of this level and > duration clearly qualifies as the type of interference that merits > direct FCC intervention. File a complaint.
Absolutely. We are right and they are wrong. If we "lay down," we have only ourselves to blame. One suggestion though for suppressing the RF trash. While I (so far) have no experience with Plasma TV RFI, MOST RF trash from electronic products, especially the stronger part of it) is radiated as a common mode signal by wiring both inside and outside the product. We can't do anything about the wiring inside the product, but we can kill the RF current on the EXTERNAL cables that connect to it, like the power cable, the coax cable(s), and any audio and video cables. To kill RF current on ANY cable, form a common mode choke by winding turns around a ferrite toroid (or clamp-on). 14 turns on a #31 2.4-in o.d. toroid is about right for 1-10 MHz, and 8 turns on a 1-in i.d. clamp-on. For the higher HF bands (14-30 MHz), use 8 turns around the toroid (either #31 or #43 mix) and 5 turns through the clamp-on. Use a separate ferrite core for each choke. If you have trash on all the bands, use both chokes on each cable. This may or may not help, and it certainly won't help the part of the trash radiated by internal wiring, but if I had RFI from a plasma set, I sure would try it before throwing up my hands. Lots of detail, including the technical explanations of why this works, is in http://audiosystemsgroup.com/RFI-Ham.pdf 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
