Here in the Chicago area, there's a "new kid on the block" at 640 on the AM dial. WMFN, which relocated from the Grand Rapids, Michigan area.
Days: "New Kid" WMFN is in with a fair signal. 4400 watts from 70 miles to my south-southeast. On a REALLY good radio, you sometimes might be able to hear WOI with WMFN nulled..
Nights: WMFN goes down to 1600 watts with a pattern slightly more favorable to my location than their day pattern. The result for me is that the signal at night is nearly as good as day signal. WOI is usually what's audible underneath. Or null WMFN, and WOI will be there with a listenable signal more often than not.
Retro: KFI was not exactly a regular for me, but it would be in with a listenable signal from time to time back in the 1960s and 70s. Later, when WOI was granted nighttime service, it was the usual occupant of 640 at night at my location. WHLO was an occasional visitor around sunset
When WMFN was located in Michigan, the day signal was weak. At night, WOI usually took over, but I'd still hear WMFN undernath from time to time.
Days: "New Kid" WMFN is in with a fair signal. 4400 watts from 70 miles to my south-southeast. On a REALLY good radio, you sometimes might be able to hear WOI with WMFN nulled..
Nights: WMFN goes down to 1600 watts with a pattern slightly more favorable to my location than their day pattern. The result for me is that the signal at night is nearly as good as day signal. WOI is usually what's audible underneath. Or null WMFN, and WOI will be there with a listenable signal more often than not.
Retro: KFI was not exactly a regular for me, but it would be in with a listenable signal from time to time back in the 1960s and 70s. Later, when WOI was granted nighttime service, it was the usual occupant of 640 at night at my location. WHLO was an occasional visitor around sunset
When WMFN was located in Michigan, the day signal was weak. At night, WOI usually took over, but I'd still hear WMFN undernath from time to time.