In recent years, I have had increasing difficulties receiving a favorite FM radio station in and around McLennan County. The difficulties take the form of "fringe area" reception: two stations interfering with each other on the same frequency.
My favorite station is KNCT-FM 91.30, a public broadcasting station headquartered on the campus of Central Texas College in Killeen, Texas. It has been broadcasting from there on that frequency for decades. On the map, this is about 45 air miles from Waco, Texas. Technically, I suppose this might be considered a fringe area for reception, but I never had reception troubles 5 years ago.
I finally identified the competing signal that "walks all over" KNCT-FM: it is a Christian station located in Decatur, Texas: KDKR-FM 91.30. This is near Lake Bridgeport, northwest of Fort Worth. On the map, this location is very close to 140 air miles from Waco, far beyond the 40 mile radius some consider "fringe".
140 vs 45 miles is 3.1 times as far away. Since broadcast radio signal strength varies inverse-square with range, and I see equal signal strengths in Waco, KDKR's apparent transmitted power is about 10 times that of KNCT.
Preventing this kind of interference by not licensing two stations on the same frequency that are too close, is one of the FCC's primary and most fundamental job responsibilities. Clearly, in this case, the FCC failed miserably.
I want to know two things of the FCC:
(1) Why did you license two stations under 200 miles apart on exactly the same 91.30 FM frequency?
(2) Why did you license the newer one (KDKR) at 10 times the power required for a nominal fringe area reception radius of 40 miles, thus pushing its actual fringe radius to an apparent 140 miles in Waco?