ar-t wrote: > OK, one more observation on SMPS. I'll try to be as brief as possible, > which isn't always easy for a nerdy engineer. > > Relative to 20-25 years ago, I can tell you the noise floor, in the 10 > MHz region, is about 20 dB higher than it was back then. This is as > measured off of an antenna we have strung up, for various "shortwave > radio projects". (Don't ask why..............you really do not want to > know.) > > Below 10 MHz, it is worse, but we do not have any recorded data of what > is was way back when. So, no way to say how much it has gotten worse, > with the proliferation of SMPS, CFLs, and LED lighting. > > And speaking of which................ > > If you have to replace a fluorescent ballast, they do make ones > specifically for residential applications. Trying to find one at the > local home improvement store might be tough. I believe some ham radio > dorks sued the big one, because one of their worker drones said it was > ok to use one designed for commercial use in their home. > > (I have both, at my house. Both mess up hand-held SW radios, but I > honestly can't tell you which one is which, using the radio as a > measurement device.) > > All for now! (Aren't you relieved?)
That is absolutely the truth. And it has gotten worse below 10 MHz, too. And it gets into everything. Passive mains filtering catches only some of it. Years ago, all I had to worry about was a little RF on the line and some compressor and motor noise that was manageable. Some of these new high E chargers and AC supplies are noise machines. Fortunately, commercial OTA at the tower (here in the US) has gotten so poor in quality that it seems to balance out, and I don't feel I am missing anything anyway. But I am probably going to start putting in some active measures soon to tamp down some of it, as noise wave-form cancelling technology has dramatically improved in the past 5 years. ------------------------------------------------------------------------ sgmlaw's Profile: http://forums.slimdevices.com/member.php?userid=13995 View this thread: http://forums.slimdevices.com/showthread.php?t=82648 _______________________________________________ Touch mailing list Touch@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/touch
