friend named "Jack", who offered to take over for him while Caldwell left for an early 4 July visit to South Padre Island), the station flipped to Adult Hits as 100.3 Jack FM. The first song was "Where the Streets Have No Name" by U2. The Jack FM format had been successful in a number of Canadian cities; CBS began putting it on several of its FM stations around the U.S., including Los Angeles, New York City, Chicago and other markets. With the flip, KRBV's call letters changed to KJKK. For the first 11 years, KJKK was jockless, and rejected all song requests. It used the voice of Howard Cogan to make quips and sarcastic remarks several times each hour instead of having a DJ, but in late of 2015, the station added an on air staff while still keeping Cogan for station imaging. In the summer of 2016, KJKK dropped the "Playing What We Want" slogan, and changed it to "Everyone Agrees on 100.3 Jack FM". In early 2020, KJKK brought back the “Playing What We Want” slogan. To this day, Jack FM remains the second longest-running format on 100.3 MHz behind the beautiful music/easy listening format in its earlier years. The station's playlist has a core focus on hits from the 1980s and 1990s, with some songs occasionally going back to the 1970s, 1960s, and even the 1950s. Most of the music is from mainstream rock and alternative rock, although other songs from the Top 40 charts are included. The KRBV call letters eventually went to a Los Angeles station for several years, also at 100.3 FM, but under different ownership (now KKLQ, owned by the Educational Media Foundation). On February 2, 2017, CBS Radio announced it would merge with Entercom. The merger was approved on November 9, 2017, and was consummated on November 17. HD Radio HD2 KJKK's secondary HD Radio channel was initially launched as "My HD" in 2004. In early 2008, it carried Las Vegas-related jazz standards sound under the branding "The Sound of The Strip." In May 2018, "The Sound of the Strip" was replaced by urban contemporary-formatted "V100.3 HD2" with the tagline "DFW's New Hip-Hop and R&B." It is similar to the "Adult Mix V-100.3" format previously heard on the main 100.3 frequency from 1998 to 1999. As of October 2021, KJKK-HD2 switched to a classic country format previously heard on the HD3