re: Note from Paul Rampelbergh/Wezembeek-Oppem (Belgium) Well before the proliferation of electronics products, the world was deeply entrenched with wireless communications. This included radio, TV, flight controllers, police, fire departments, and so on. When household and industry electronics began to interfere with these forms of communication, virtually all countries began to adopt rules to "manage" the electronic spectrum to avoid interference.
It is interesting to note that most such rules apply only to "digitial" equipment, i.e. with oscillators operating at 10kHz and above. Home and industry appliances such as vacuum cleaners, blenders, arc welders, etc. are usually not required to meet the same requirements. This may be due to the fact that they emit broadband, as opposed to discrete frequency) noise. Or it may be due to other socio-political factors. At one time, FCC, VDE, and CISPR 22 requirements differed a slight amount at particular frequencies. Now, CISPR 22 requirements are becoming acceptable for most countries. For very small developers/manufacturers, the best solution is to develop a close working relationship with a nearby EMC test agency, which already has the necessary equipment, test chambers, and expertise. The fees for ocassional testing will be small compared to the capital investment necessary to develop self-test capability. These can only be justified when the amount of products and testing becomes larger. George Alspaugh Lexmark International (personal opinions)
