I've been researching the possibility of exploiting the Part 15 rules for use of low-power Digital Radio Mondiale (DRM) broadcasts on the MW band within the USA. I've asked the following question on various forums without any concrete response so far. Do Part 15 rules allow for broadcasting low-power DRM within the USA on the MW (~ 522 KHz to 1710 KHz) band? The FCC granted iBiquity the exclusive right to broadcast their proprietary format of digital on MW at normal power levels, but did that "exclusive" right override low-power, Part 15 rules? Personally, I'm not sure and apparently no one else is sure either. The UNOFFICIAL consensus of a few other low-power broadcasters seems to favor proceeding with broadcasting DRM via Part 15 rules. With the potential legal hurdle temporarily aside, is it technically possible to broadcast DRM at such low power levels of 100 mW? Well, only experimentation will verify the possibility. Unfortunately, low-power DRM transmitters conforming to Title 47, Part 15.219 rules aren't currently available. Since each low-power station can have upwards of FIVE transmitters, it's possible to create a radio station with a potential audience of at least 15,000 people and upward of 22,500 people at 3,000 people per square mile.
Under IDEAL conditions, a low-power, Part 15.219 AM ANALOG broadcast can travel upward of ~ 1 mile with a well-engineered antenna and nearly perfect environmental conditions. More realistically, the average range for a low-power, Part 15.219 AM ANALOG transmission would vary from ~ .5 to .75 mile. With FIVE transmitters and omni-directional antennas (~ $2,500) located strategically around a city, one station could cover quite a bit of territory, i.e. a MAXIMUM radius of 3.75 miles or 7.5 miles in diameter. DRM broadcasts are allegedly even more power efficient that analog broadcasts so the potential range MIGHT even be further than analog.
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