Anytime there is high-speed digital logic in operation there is RFI being generated. After all, those "logic" signals are no different from a square wave RF signal, and being square waves means they have very high levels of harmonic energy across the spectrum.
The big difference is that a plasma panel generates high-energy RFI directly in the display which then radiates it through the screen. As you noted, the level of RFI will be much lower with LCD sets and, in many cases, can be suppressed further with proper treatment of the various wires leading to and from the set. 73, Ron AC7AC -----Original Message----- I also had a Plasma TV, a 42 inch Visio purchased many years ago, and had the terrible RFI problem on 80 meters especially. My 80 meter dipole hangs across the house , one leg over the plasma. I never operated much in the lower bands where the RFI was worse, but figured I would eventually get a LCD or LED TV and the problem would go away. Well, the day came and I was itching to get a larger screen TV. I saw another Visio (they have good clear displays), so I thought I would opt for a LCD 55 incher. i had forgotten about the RFI problem with the plasma, but heck, this is a LCD so it should not have any problem. I got it home and really liked it. Well, as you might expect, I was on 80 meters working some CW one night and on the P3, I saw these little spikes, maybe 160 KHz apart (-85 dBm +/- a few dB). I hollered at my wife to turn off the TV and well, you guessed it, the spikes went away. So, in my case, an LCD TV does have some RFI, although not as much as the plasma. Interesting, a 32 inch LCD Visio in the shack has no RFI as best I can tell and the dipole goes directly over the shack. ----- Roger W5RDW -- ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
