The bigger picture is WVLK-AM overcoming a night pattern that misses most of the metro. When the station signed on the air it was licensed to Versailles, the "V" in WVLK. The night pattern drops the bulk of the signal to the southwest towards Versailles. The nulls weren't a problem in 1947 but like most post war AM's it became an issue. The Atlanta null goes right down Man O War Blvd and much of what is now population.
When I worked there thirty years ago there were several theories of overcoming the problem. Most costly was moving the tower farm which was cost prohibitive. Another suggestion considered was leasing programming time after seven on WLAP since their nulls weren't as bad and simulcasting. They had a CP to increase power to 1600 watts at night but that expired. A plan that almost happened in the early nineties was leasing or purchasing 101.7 Richmond and simulcasting. However, the Kentucky Central collapse happened so the plan was scrapped. Ironically WVLK and 101.5, formally 101.7 prior to the upgrade, became co-owned and 101.5 provided the simulcast. But for some reason they gave that up for Nash Icon.
Bottom line is something has to be done to the 590 physical plant. The audio quality is horrible and doubtful they are operating at 5kw days. The night nulls have moved, especially the Atlanta null, and last time stopping by the transmitter plant a tree was growing from inside one of the tower fences.
As far as WSGS, they do have a loyal following. Are they still broadcasting mono?