Jack Diamond, a fixture on Washington’s radio airwaves for more than two decades, may have broadcast his last program on WRQX-FM, the station known as Mix 107.3.

Diamond was scrubbed from the station’s Web site after his broadcast Friday morning. Station Manager Mark O’Brien said in an e-mail that an announcement about Diamond’s replacement would be made Monday.

“The Jack Diamond Morning Show” has been Mix 107.3’s marquee attraction for 24 years. It predates the station’s changeover in 1990 from a Top 40 station to an adult-contemporary outlet aimed at women.

A throwback to an earlier age of broad, general-interest programs, the “Diamond” show mixed topical humor, interviews and listener call-in, with Diamond overseeing a rotating cast of sidekicks.

The show has slipped somewhat in the Arbitron ratings but has remained formidable, finishing 11th overall and 12th among listeners 25 to 54 years old, a key segment for advertisers.

Diamond, who got his start in radio as a teenager in Montgomery County, could not be reached Friday for comment.

— Paul Farhi