830 WQAO-AM, first launched on on March 4, 1923. The station was owned by Calvary Baptist Church and only cost $1500 to build. Chief engineer George F. Koster, who was a church sexton did the honors. In 1926 they moved to 760 and began a share-time agreement with WHN-AM and WPAP-AM. In 1931 WQAO bought out WPAP and continued operating both stations. In about 1928 they all three moved to share time on 1010 with WRNY making it into an ugly 4-way share. In 1934 WHN-AM bought out WQAO and WRNY effectively unifying the license. But WHN granted time to the Church to seal the deal. That's not surprising since he'd done the same while they were building their station. They went on to sponsor the Cavalry Baptist Hour on WMCA-AM. More here.
So WQAO existed from 1923 to 1934, a total of 11 years. It was located in the basement of a church at 123 West 57th Street in New York City which is still a Cavalry Baptist Church. Though in 1925 the original building was demolished and replaced by a 16-story behemoth. They only broadcast for an hour and a half on weekdays 11:00AM - 12:30 PM, an extra hour Wednesday morning at 7:30 and then 2 hours on Sunday mornings. That's only ten hours of programming. Why is this interesting? Well the cavalry baptists still produce both a daily and a weekly program still aired on WMCA-AM in New York and WWCR on shortwave (15.825 MHz) out of Nashville. More here.
Most memorable from their brief 11-year heyday was Pastor John R. Straton. Time magazine quoted him in 1953. "I hope that our radio system will prove so efficient that when I twist the Devil's tail in New York, his squawk will be heard across the continent. .. I shall continue to do my part, as the Bible expresses it, in tearing down the strongholds of Satan." He was firmly, fundamentalist and opposed pretty much all known forms of fun. The book I Looked and Listened by Ben Gross described him briefly
"...A powerful voice denouncing divorce, evolution, atheism, corrupt politicians, and every aspect of "modernism." It was that of the famous fundamentalist pastor of the cavalry Baptist Church, the Rev. Dr. John Roach Straton. It was he who initiated the "world's oldest radio gospel service," which first attracted listeners because of his salty castigations of the shimmy, the "orgies" in Broadway cabarets, the Elewell murder mystery and those who devoted themselves to the Ouija board."He was a hellfire and brimstone nutbag. He really thought that dancing was the leading cause of immorality. He was a teetotaler and a bigot. In 1928 he became entangled in the presidential race betting heavily on Herbert Hoover [R] over Alfred Smith [D.] Smith was a (gasp) Catholic. Straton labeled Smith "the candidate of rum, Romanism and rebellion". The Reverend toured the country trying to take down Smith. Hoover won of course but the campaign seemed to take it out of Straton. He had a couple heart attacks and retired to Finger Lakes, NY where he had a stroke, a nervous breakdown and a heat attack in that order. He died in 1929. More here