This is all water under the bridge, but I was wondering what the improvement in WJR's groundwave would have been in Kalamazoo, MI if they had been authorized for their 500 kW DA back in the 1950s. Kalamazoo (ZIP 49001) is well into the region of 4 mS/m and 2 mS/m soil on the FCC M3 conductivity map, ~120 miles on a compass bearing of N275.1°E from the WJR transmitter site.
- For 50 kW non-D operation, the field from WJR in ZIP 49001 is about 0.36 mV/m.
- For the 500 kW DA pattern shown below, their field in ZIP 49001 would have risen to about 1.3 mV/m.
For perspective, WJR now has a GW field of about 1.3 mV/m near Bay City, MI, and that Tri-City area had plenty of listeners to WJR back when I grew up in Saginaw. I suppose WJR still might have plenty of listeners there, if their programing now matched what it was back then — with local talent including J.P. McCarthy, Karl Haas, Mike Whorf, Ted Strasser, Bud Guest, Jimmy Launce, Jay Roberts, Charlie Park, etc.