Wikipedia
WWJZ
WWJZ ( 640 kHz) is an AM radio station licensed to Mount Holly, New Jersey, serving Philadelphia and the Delaware Valley. The station airs Catholic talk programming and is owned and operated by Relevant Radio.
The transmitter is located near the intersection of U.S. Route 206 and CR-530 in Pemberton Township, New Jersey, and station offices are in Fort Washington, Pennsylvania. WWJZ operates at 50,000 watts in the daytime, the maximum permitted for AM stations by the Federal Communications Commission. But because 640 kHz is a clear-channel frequency, WWJZ must reduce power to 950 watts at night to avoid interfering with other radio stations.