Maybe this was written by the same guy who claims that my shop vacuum has 6 horsepower.
Carleton -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Hooper Sent: Wednesday, May 25, 2005 20:12 To: U.S. Metric Association Subject: [USMA:32913] kHz infra-red? I recently read some information about a TV listening device for the hard of hearing. It transmits the television sound by way of an infra-red beam from a transmitter at the TV to a listening device worn by the TV viewer.* The information I read states that the signal is transmitted by "95 KHz infrared". That didn't look right to me (and I don't mean just the incorrect capitalization of the "k" for "kilo") so I looked up the frequency of infra-red radiation and found it to be roughly between 100 GHz and 500 THz. These are, respectively, one million and five BILLION times higher than the 95 kHz in the information.** Are they just way off on their figures, or is there something here that I don't understand? Could the 95 kHz be a frequency at which the much higher frequency infra-red waves are modulated or something? Anybody have any ideas on this? Regards, Bill Hooper * Apparently U.S. federal law will be requiring movie theaters to transmit these infra-red signals, too, so the owner of this device may take it to the theater and use it to hear the sound track of the movie. ** The relationships are: 100 GHz = 100 000 000 kHz 500 THz = 500 000 000 000 kHz compared to 95 kHz (approx. 100 kHz).
