11 October 2004
Wish I'd thought of this
It's a step beyond serendipity: the ability to claim credit for an innovation that requires you to do nothing at all.
Tulsa's KOTV, channel 6, is now promoting its Online Audio at its Web site, and you don't even need to be online to listen to it: just tune your FM radio to 87.7 MHz.
Under FCC rules, an analog TV channel covers a bandwidth of 6 MHz; channel 6 runs from 82 to 88 MHz. The color subcarrier is generally located 1.25 MHz from the bottom of the channel, or at 83.25 MHz.
TV video is AM. TV audio, however, is FM, and the FM subcarrier is located 4.5 MHz above the video subcarrier in all TV channels. On channel 6 in Tulsa, or indeed channel 6 anywhere in the US or Canada, this means 87.75 MHz. (Actually, some stations, including KOTV, are required by the FCC to offset their subcarriers by 0.01 MHz, so the actual FM audio from KOTV is at 87.76 MHz.) This signal is well within the reach of any FM receiver within transmitter range which can be tuned to approximately 87.7, and KOTV didn't have to do anything extra to provide it; it's a by-product of the way the spectrum is assigned. Any station on channel 6 should be similarly accessible.Posted at 6:26 AM to Overmodulation