While WYMM-AM is authorized for 50KW, I agree with GeorgeJ that they're most likely running less than 50, but unless there's a real problem with the transmitter, it's closer to 50, probably around 30KW. But there are many other factors affecting their signal, ground conductivity, the condition of their ground system (radials), their high dial position, plus they ARE directional, and as was already pointed out, do not put out a good signal to the north of their Westside transmitter site.
The WYMM signal gets really weak, really quickly when heading to Jax International on I-295, and cannot be heard at all in most of the Fernandina Beach area. But they do have a rather good to the South/Souitheast and West. A potential owner would be looking at having to re-haul that facility to bring it back to specs. Also, since WYMM seems to be too close to 1530 in Cincinnati, they have no pre-sunrise authority, and, very little chance of 24 hour operation without a companion FM or FM translator. BTW, there are 4 50KW AM's in Jax WOKV 600, WJXL 1010, WJNJ 1320, and WYMM 1530. WOKV and WJNJ are the only non-directional 50KW's during the daytime here, and, it should be pointed out, none of them is authorized for 50KW at night. In other words, Jacksonville does not have any fulltime 50KW AM facility.