Hi all Funny to see how questions which seems to too simple, can turn out to be difficult. I have been into to the same problem before.
I think we need to look at the FCC text it self. The definition in 47 FCC Part 15 Subpart A says: 15.3 (z) Unintentional radiator. A device that intentionally generates radio frequency energy for use within the device, or that sends radio frequency signals by conduction to associated equipment via connecting wiring, but which is not intended to emit RF energy by radiation or induction. 15.3 (n) Incidental radiator. A device that generates radio frequency energy during the course of its operation although the device is not intentionally designed to generate or emit radio frequency energy. Examples of incidental radiators are dc motors, mechanical light switches, etc. The 9 kHz comes from: 15.3 (u) Radio frequency (RF) energy. Electromagnetic energy at any frequency in the radio spectrum between 9 kHz and 3,000,000 MHz. If it was using a timing signal over 9 kHz it will be a digital device, and please notice some audio amplifiers are now using switching technique and can bring them into digital devices (see definition below): 15.3(k) Digital device. (Previously defined as a computing device). An unintentional radiator (device or system) that generates and uses timing signals or pulses at a rate in excess of 9,000 pulses (cycles) per second and uses digital techniques; inclusive of telephone equipment that uses digital techniques or any device or system that generates and uses radio frequency energy for the purpose of performing data processing functions, such as electronic computations, operations, transformations, recording, filing, sorting, storage, retrieval, or transfer. A radio frequency device that is specifically subject to an emanation requirement in any other FCC Rule Part or an intentional radiator subject to Subpart C of this Part that contains a digital device is not subject to the standards for digital devices, provided the digital device is used only to enable operation of the radio frequency device and the digital device does not control additional functions or capabilities. Note: Computer terminals and peripherals that are intended to be connected to a computer are digital devices. Conclusion: As I see it the product is not a digital device (audio over 9 kHz is not a timing signal), the product is an Unintentional radiator, the product is thereby under Verification ( see 15.101 other devices). Best regards, Kim Boll Jensen Bolls Rådgivning Denmark Fra: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]På vegne af Colgan Christopher [Soundcraft UK] Sendt: 2. oktober 2003 11:07 Til: ieee pstc list Emne: RE: FCC part 15 verification Thanks for the replies. I'm now happy that an incidental radiator doesn't need Verification. But now I'm confused as to whether and audio amplifier is an incidental or unintentional radiator. As the amp does not intentionally generate energy over 9kHz (it merely processes it) would it not be an incidental radiator? Regards Chris Colgan From: Cortland Richmond [mailto:72146....@compuserve.com] Sent: 01 October 2003 22:05 To: richwo...@tycoint.com; ieee pstc list Subject: RE: FCC part 15 verification Richard Woods wrote: >> An audio amplifier that processes signals over 9 kHz is considered to be an "unintentional radiator" and must be verifified. << I don't believe I've heard of the FCC actually requiring analog audio gear to be verified, though even a cheap record player with 10 KHz audio does fall under the definition (uses >9KHz signals) of an unintentional radiator. What the heck, a _crystal radio_ falls under that definition. However, here's an interesting look at the REALLY OLD days: "... we had a two hundred kilowatt Federal arc that was a Poulsen arc operated on DC, together with a 3300 foot self-supporting steel tower and an antenna stretched between three towers. In those days we spoke in terms of meters, but the wavelength in kilocycles was somewhere between fifteen and twenty kilocycles. If I am correct, I remember we could hear the similar installation at Panama without rectifying the signal, those of us who had good hearing. I mean it came out as an audio signal. ..." http://www.ieee.org/organizations/history_center/oral_histories/transcripts /stone9.html Cortland This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
