1090 and 690 here in the Chicago area have become relatively open channels. 1090 still produces KAAY on a regular basis. but the signal has become much weaker than it had been during KAAY'S top 40 days in the '60s and 70s. 690 has "eroded" even more. CBF from Montreal had dominated the channel with a good signal. The present Montreal 690 is still 50kw, but has a tight pattern not favorable to my direction. A weak WQNO from New Orleans is usually the most likely catch around here...IF their pattern is leaking.1090 has a 50 kw in Seattle, as well as Baltimore and Littlr Rock and a bunch of mid-America ones. XEPRS protects them. 690 even has a primary station in Mexico City, so Tijuana protects it. And 690 is mostly Canadian, but with some US stations like Coffeyville, Jacksonville and Honolulu with decent nigh power.
Thinking of that, 940 is also well used in the US at night, but most of the ones I listed are fully dominated by Mexico
940 used to be a reliable CBM from Montreal. Nowadays it's 500-watt WFAW from Fort Atkinson, WI via groundwave and favorable pattern without much to stop it. (55 miles)

