I apologize for accusing you of possible "flaming".
I would not suspect the ground system. If it were the ground system, the impedance of the array at night (70 ohms j0) would drift, and the Harris transmitter would go ape.
No doubt AM faces many issues with man-made interference that did not exist in 1950. I live about 75 yards from tolley lines. However, standing near a concrete building (Miami Valley Center Mall) full of flourecent lights, and fed with 3 phase electricity is a lot different from being in a house in Miami County, and trying to receive the signal.
However, looking at the directional pattern indicates (to ME anyway) the more efficient use of resources would have been to use 95.3, which is stronger in known pattern nulls, such as Bellbrook, by Wal-Mart / Kohls in Greene County. The buildup since 675 went in has reduced the already miniscule signal there even more. WHIO protects WTKS in Savannah, GA (a station I installed NexGen in), and that is why the signal is bad in Bellbrook. I see that area growing faster than Clark Co.
Note the lack of 1290's signal in Warren County just south of the Dayton Mall at night.. Sure you can hear 95.7 there, but try to hear it on a boom box. 95.3 is a stronger signal there. Were I a Cadillac dealer, I would rather sell Caddys in a growth county, like northern Warren, one of the fastest growing counties in the USA, than Clark. No matter what Arbitron says, northern Warren County is still considered a Dayton suburb by those who live there. Who cares about Butler Co. (Middletown)? Who cares about Lima? Who cares about Columbus? All cities I heard on the newscast about this big change.
There is a null in Kettering near the Dayton Country Club. I am sure 95.3 would fill that null WAY better than 95.7.....and thats in the METRO.
95.7 could have been used to better compete with the Eagle, or better yet, the original ZLR format on a full 50Kw Class B signal, instead of the directionally crippled Class A on 95.3 It seems to me the whole idea of the simulcast would be to INCREASE, rather than DUPLICATE EXISTING coverage for 1290.
Anyone can "Monday Morning Quarterback". All I stated originally was an opinion. My name isn't on the license.
ER