Stations are spaced on co- and adjacent 1st, 2nd and 3rd channels from other stations based on Class of both stations. It is based on long standing intermod and signal coverage studies done back in the 1960s.
LOW POWER (LPs) are legally limited to 100w ERP at 100ft max...or equiv. If they go higher than 100 ft, then power must be reduced to keep the signal contour withing the same range...but their 1mV contour cannot exceed the distance they would get at 100ft/100watts ERP.
The 1mV signal contours (called the service contours) are protected from co and adj channel interference...a 106.1 or 102.5 increasing power will cause issues with adj signals with a large power increase...Most 2000 ft/100kw Class Cs are spaced up to 180 miles apart..(the 60dbu/1mV contour is about 60 miles out from the tower...in some cases it may be less if the station is directional)
It is what it is due to MATH....103.3 in Freeport (tower site actually Sargent 1 mile from the coast!) is landlocked..due to 102.9..Bill Cordell tried to get Dave Morris to allow him to move 103.3 5 miles north for a better tower location and in reality, it would not have caused any more issues to 102.9 (which is short spaced with Lafayette, LA already) but Uncle Dave refused to let Bill do it (102.9 can never move to Sr Road from Ennis St tower)...
KJOJ has a CP to go 2000 ft (the tower is only 1000 ft or so)...but that will likely never happen....Liberman has money issues and a new 2000 ft tower would cost 3-5 million....Liberman has already sold off its 98.5/107.9 Devers tower and the 93.7 tower NW of Fort Worth to Tall Towers Ventures and is leasing them back....that way, they can write off the rent off the bottom line...rather than have to pay taxes, upkeep costs, etc which are capital expenses and hurt the profit margin.
Centerpoint Energy's gas side does the same thing..they LEASE everything..PCs that you can buy for $800, they lease for 3-5 years and the overall costs at the end of the lease is MORE than $800 (more like 2 to 3x!!)..but playing with the numbers in the books as leases, etc makes their bottom line and taxes look better..the electric side BUYS everything...but they are under the PUC and are guaranteed a 12% return on investments....the gas side is under the Railroad Commission and has no such ROI guaranteed!!
And we wonder why American business is sooo screwed up
