Tuesday, December 05, 2006

Federal Communications Commission and Ribbon Microphones

In the US, the Federal Communications Commission (FCC) is the primary regulatory body empowered to develop and enforce rules and regulations pertaining to the use of electronic equipment that interacts with radio wave energy. The FCC also regulates cable TV and even the content of radio and TV broadcasts, and levies fines on broadcasters who violate the rules as they are interpreted at the time. The US is an odd place where allowed TV content consists of obscene amounts of violence and depictions of hatred, destruction, murder and gore that are well-tolerated by the FCC, yet virtually any depictions of sex, naked human bodies, lovemaking or natural human processes are forbidden, unless they are images of nude saints or classical paintings of nymphs or other Fine Art forms. Even these are usually masked in such a way so the essential bits are missing.

But we like the FCC anyway, because they are the regulatory body that sets the standards for RF emission and immunity in electronic equipment. For instance, the FCC requires that most consumer electronics meet what are referred to as the Part 15 rules. This means that a preamp, for instance, or an amplified microphone such as a condenser or even a ribbon microphone with an amplifier in it, must be tested and certified by the manufacturer that it won't exceed certain limits of RF radiation. This helps everyone because it keeps the level of noise down and reduces the propensity of various electronic devices such as PCs and mixing boards to interfere with each other.

You can look on the label of any active electronics to see if it has the FCC symbol on it. You will often see the CE mark, which is essentially the same rule for Europe, and TUV and other symbols that variously indicate that the device conforms to the particular country or regional rules. Manufacturers who do not do this with their active electronic devices are taking a chance. In one case, a prominent audio manufacturer was fined for faking the FCC Part 15 certification on its equipment.

All Crowley and Tripp Ribbon Microphones are passive devices and have no amplifiers or active electronics in them. Yet we do conform to RF immunity testing according to the Electromagnetic Compatabilty Regulation 2005 - (S.I. 2005/281), The Electrical Equipment (Safety) Regulations of 1994 (S.I. 1994/3260), CONSLEG:1989L0336-02/08/1993, FCC Part 15 CE. We test our microphones for RF susceptibility to various RF sources and also low frequency electromagnetic fields, and we design the microphones so they will be as immune as we can make them to those sources of interference. A low noise floor is important! We also compare our RFI immunity against competitors, and we believe we have better RF and magnetic shielding than others we have measured.

That FCC logo is somewhat odd one but one that I like: It shows an eagle carrying some radio waves (or destructive lightning) over to an antenna installation. It even show a pair of towers, a wire strung between them, ham radio style, and a transmission line.keyword fcc royer Robert J Crowley Bob Crowley behringer

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