We are looking into setting up a simple 3m pre-compliance site in-house, because our ambient signals are just too high for the on-off method to work.
I am looking for information on the relatively low end of the price range: an anechoic chamber is not an option. I am thinking of things like wire mesh cages, so-called "EMI tents", using foil to shield an existing unused meeting room, etc. What do we do about the door seam? What do we put on the floor, etc, etc. Does anybody have any information regarding sources for materials and installation or design expertise for these sorts of rooms? Do we need to hire a consultant to help us set up a usable facility? If so, can anybody recommend someone really good in the Pacific NW? Also, we are finding that a lot of noise on the AC mains is getting past our LISN's, and have tried small equipment EMI filters ahead of them, to no avail. I have heard there are "facility filters" available that roll off everything above power frequencies by 70-100dB. Does anybody know where we can get something like this at a reasonable price, for line currents up to 50A (the size of our LISN's)? What do other people do about this problem? The limited spectrum of the incoming noise (only up to around 300kHz) makes me suspect is has to do switching harmonics from all the computers in the building. Anyone else have this problem? Thanks in advance for your help, Jim Eichner Statpower Technologies Corporation [email protected] The opinions expressed are those of my invisible friend
