On some occasions during gray line, I tune into KCMO 710 up here and get echo. Considering they're a 50kW, I figure we're getting groundwave & skywave for a time.
However, that certainly is not the case for 11530. Which means if its multi-path that's causing the echo, its going long path & short path?!? I would doubt its going long path at that frequency. I'd still bet that something in their transmission system is on the fritz, which wouldn't be the first time.