I'll try to make it easy to understand

Anything owned by Birach, like 1080 is brokered programming. If nobody is leasing any airtime, they fill it with something else.

1110 is a direct example. The people that own 1110 used to lease most of 750 during the day. They wanted the entire schedule, not just weekdays so they bought 1110. After they bought 1110, 750 went to filler music, and eventually leased it out to the McCaskey Family's Sports Faith International, which owns WSFI in Antioch and runs EWTN Radio. It simply simulcast WSFI during those hours, which was most of the day during the week. They let it and the rest of the programming lapse, and now the station is all filler music.

1280 is under the same ownership as 1530 as far as I know.

1590 used to be owned by the same owner as 1280 and 1410. He sold all of them. 1280 is with 1530's owner now, 1410 has local ownership now.