Denigrates the signal? Sure, because the signal sucks! At least after dark. This is why WCRN in Worc. has him... when it gets dark before 6 pm he has to tell people to tune to AM 830 because RKO’s signal fades (by FCC regulations, the station must push its signal north and south after dark to avoid interference)
Basically switching from a non-directional (circular) antenna pattern to a bi-directional (figure-eight) antenna pattern.
WRKO aims its signal from north northwest south southeast so as to protect KNBR 680 in San Francisco (which can be heard at night here in Montana) and WPTF 680 in Raleigh, NC, so it's very strong in NH and on the Cape. Strongest signal is toward the Cape and out toward the ocean.