WSUN radio station began operating at 620 kHz in October 1927 having previously shared time with WFLA. In 1928 it was moved to 580 kHz, then to 900 kHz that year. In 1929, radio frequencies for stations in Florida were reallocated, the station at this point moved back to 620 kHz, where it remained until 1998.
The stations transmitter was originally on the north side of the Courtney Campbell Causeway near Clearwater. Early in its return to 620 kHz it was able to increase its power by being the first AM radio station in the world to add a second tower and use placement and spacing along with divided power from the main tower to directionalize its broadcast coverage area. The state of the art at the time thought the signal was traveling west to the Mississippi River and then north to interfere with the WTMJ 620 kHz station in Milwaukee. The British engineer phased the new antenna array to produce a null to the radiated signal directly to wards Milwaukee. This fostered a new understanding of RF behavior, having been so successful the Federal Radio Commission in Atlanta reportedly phoned, demanding to know why the station was off the air. As late as the 1990s, the original tower bases remained in their field, the station having moved to straddling the west end of the Gandy Causeway with 501 foot towers on concrete pilings in the Tampa Bay salt water in the early 1950s at 5 kW. A radio war with Cuba granted it an STA to operate at 10 kW from the 1990s on to overcome deliberate retaliatory interference. All RF and electrical power and control cabling was run under the divided Gandy Highway in conduits that have an access manhole in the median and rise up out of the ground to the tower platform on the south side of Gandy "Redneck Riviera" Beach. The City of St. Petersburg eventually placed a channel 38 antenna on top of the north tower and a microwave reflector to deliver the programming to the transmitter building below. The weathered towers were replaced with shorter self supporters in the early 2000s with LED lighting.
Originally built and operated by the City of St. Petersburg, Until 1974, the station offered a variety of programming including dramas, talk, music, and was an ABC affiliate. In 1974 the station switched to country. In 1987 it switched to a news/talk format which remained until 1995, when it switched back to a music format. During the 1987 until the Cox radio purchase it had returned to a country format, then changed upon purchase to a hot talk format as the station was the home of the popular syndicated morning program The Ron & Ron Show (Ron and Ron) as well as hosting the Hooters-on-the-Radio show, Bob Lassiter (deceased), and a variety of other programs, including a psychic call in show with Gary Spivey, beating all other talk stations and national syndicated talk hosts. For a brief period, the station simulcasted programming from sister stations KFI Los Angeles and WIOD in Miami, including Neil Rogers, Rick and Suds, and Chris Baker. The station also broadcast the Miami Dolphin NFL games. The nationally syndicated program "Smoke This" got its start on WSUN, now on WFLA. The successful programming was neglected by the Cox Radio CEO and allowed to implode, resulting in the purchase of a small 910 kHz station in Plant City and simulcasting its sports programming. When Cox sold the station the calls WSUN were kept and moved to a failed oldies format on a Pasco County 97.1 which was soon replaced with a successful "Music of Your Life" spinoff format.
In 1998, 620 kHz became a simulcast of Bay News 9, and the call letters were replaced with WSAA. The station was ultimately sold to Salem Broadcasting, who converted it to a Christian station and changed the call letters to WTWD (and later, WTBN) in 2001.
- http://www.alacrastore.com/deal- snapshot/Cox_Enterprises_Inc_Miami_News_acquires_WSUN_AM_Tampa_FL_CBS_Inc_from_CBS_Inc-31663