There's land coverage and there's useful land coverage. To use WSCR 670 as an example, that's much different from the 1950s. There was no blaring Cuban on 670 then and KBOI was at 950. Old WMAQ was heard all the way to the West Coast. Now, not so much.
WGN 720's another example. Still a sometimes catch in Hawaii, its western coverage was hampered by the presence of KDWN Las Vegas with 50 kW. But KDWN has recently cut back to 15 kW nights, and WGN is again a possible catch in the Pacific Northwest. The signal was there all along, but KDWN was in the way.
Finally, KNX 1070, the subject of much chatter recently. I could get it occasionally despite WIBC Indianapolis, WAPI Birmingham and WTSO Madison, Wis. WIBC/WFNI is a memory now, but others on 1070 have turned the station into a graveyard listen in the Chicago area. (And 640, where KFI and Cuba were virtually nightly visitors, null one and you get the other, into the 1980s, became a jumble as well because of WOI and WWLS' getting night power. Then WFMN came along and Chicago has no shot at all.)
The signal is there, but if it's swamped by another, forget it. If I was king, the clears would still be clear, and the new kids would be moved carefully to other spots, including 1620-1700.
