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
