After more than a year of angst, turmoil and even fisticuffs, the end apparently has arrived for once-mighty St. Louis sports radio station KFNS (590 AM).

Its signal has been off the air since Friday, and operations manager Mike Calvin said Sunday that he doesn’t expect it to return until after the station is sold, and that almost certainly would be in a different format from the jock-talk approach it has had for all but one of the last 21 years. KFNS parent company Grand Slam Sports is in the process of selling it to a religious group that would have church-related programming.

“It is off the air due to nonpayment of operational bills,’’ Calvin said. “I do not see it coming back on the air until the pending sale to the religious organization is finalized.”

He said the company’s debt is about $580,000 and the knockout blow came Friday when Ameren shut off power to KFNS’ transmitter because it is owed about $1,200.

Calvin said there is an outside chance that a decision could be made to pay Ameren to restore the signal temporarily, but that merely would be postponing the inevitable. And he said KFNS being on the air would not benefit the sale negotiations.