HFU HF Underground
Technical Topics => Part 15 AM and FM Station Operation => Topic started by: tybee on October 14, 2022, 2236 UTC
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I was just reading a 2014 article about the FCC opening up the 600mhz band (part 15) for tv at https://www.fiercewireless.com/tech/fcc-supports-more-unlicensed-use-tv-600-mhz-bands - - I realize its completely off-topic in regard to AM and FM broadcasting, but the article made mention of something I never knew that I found interesting...
"...Commissioner Jessica Rosenworcel pointed out how three decades ago, the commission was looking at what to do for airwaves that were designated for industrial, scientific and medical (ISM) uses. The spectrum once deemed as "garbage bands" ultimately ended up being spectrum where Wi-Fi was born. Today, nearly one-half of all wireless data connections in the U.S. are offloaded onto unlicensed spectrum..."
What struck me is that control of ISM emissions is exactly the primary reason prompting the creation of part 15 in 1938 (it was not as legend has it, because of the invention of the Philco "magic-eye" remote control, although that and phono oscillators entering the market did play a small part in the decision). I also had no clue that wifi arose from utilizing freqiency bands which had prevously always been considered as completely useless for intentional broadcasting.
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There are folks out there that like to keep analog NTSC TV alive. I remember an article in the old Stereo Review MAG, (Now, Sound & Vision.), covering the then legal Part 15 UHF TV in-house TV transmitters to use. None off those were for VHF, that flooded the markets here from Taiwan and Hong Kong, since they were double side band and not vestigial side band, back in the late 1980īs and much of the 1990īs. Lots of analog TVīs still out there, including classic TV portables, that were made pretty much obsolete with the 2009 digital HDTV mandate. There are folks out there that restore classic analog B&W and color TVīs today, and a legal loop-hole to transmit an analog TV signal, even very limited short range, in a show-room, or museum, would be nice to have. 600MHz, would be a good place to have that, with itīs UHF short range and high absorption rate on walls, foliage, and even furniture.