Total posts : 45366
This July NOUO is closer to the limits than the previous NOUO in this thread. The 550 microvolts per meter (uV/m) at 353 meters measurement is very close to what would be expected from a legal ground-mounted part 15.219 transmitter.
I did a 4NEC2 (NEC-2D) run for a ground-mounted 3 meter antenna to get a base line for a legal Part 15.219 system.
3 meter antenna mounted at ground level
Transmitter coil resistance: 20 ohms
Ground resistance: 10 ohms
RF input power to coil: .075W (corresponds to 75% eff. into coil)
Field strength at distance = 360 meters: 603 uV/m
It is clear from the two NOUOs referenced in this thread that the FCC is leaning toward a valid field-strength based approach, in addition to citing violations of the 3 meter rule, to bust part 15.219 operators rather than just simply citing a violation of the 3 meter rule.
The elaborate 5-antenna roof installation this operator used wasn’t very effective. He got about the same signal that a good ground-mounted system would produce. With all those visible antennas, he was just asking for a 15.219 violation, regardless of the measured field strength.
Of course, we can only wonder why someone complained to the FCC. The property belongs to an insurance company. That leads me to believe they were advertising their services. I wouldn’t think that would be a threat to any local licensed broadcasters, unless they are pathologically paranoid about losing a few bucks of advertising revenue.