Broadcast areaGreater San Antonio
Frequency102.7 MHz
Branding102.7 Jack FM
FormatAdult hits
AffiliationsDallas Cowboys Radio Network
FoundedNovember 20, 1967 (initial CP issued)
First air date
December 3, 1969; 52 years ago (1969-12-03)[1]
Former call signs
KTSA-FM (CP, never used on-air)[2]
KTFM (1969-2003)
KSRX (2003-2006)
Call sign meaning
Technical information
Licensing authority
Facility ID71086
ERP100,000 watts
HAAT202 meters (663 ft)
Transmitter coordinates
29°25′07″N 98°29′02″W / 29.41861°N 98.48389°W / 29.41861; -98.48389 (KJXK)
Public license information
WebcastListen live

KJXK (102.7 FM, "102.7 Jack FM") is a commercial radio station in San Antonio, Texas, broadcasting an adult hits radio format using the "Jack FM" brand. It is owned by Alpha Media with radio studios on Eisenhauer Road in Northeast San Antonio.

KJXK has an effective radiated power (ERP) of 100,000 watts, currently the maximum for American FM stations. The transmitter is atop Tower of the Americas in downtown San Antonio, off Cesar Chavez Boulevard.[3]


Progressive Rock

102.7 had its initial construction permit issued on November 20, 1967, as the FM counterpart of KTSA 550 AM.[2] On June 7, 1968, it was given the call sign KTSA-FM, which was shortened to KTFM prior to sign-on. KTFM officially went on the air for the first time on December 3, 1969; 52 years ago (1969-12-03).[4] It was originally owned by Waterman Broadcasting of Texas and it largely simulcast KTSA.

In 1972, management to switch KTFM to progressive rock.[5] This format lasted until 1976, when it shifted towards a more structured album rock format, playing the most popular tracks from top selling albums.

Top 40

In 1980, the station dropped its album rock format for Top 40/CHR. Its Top 40 format would later evolve into a Rhythmic Top 40 formula in late 1988. KTFM was one of three dominant Top 40 stations in San Antonio, competing with the other two dominant CHR stations, 96.1 KSAQ (now KXXM) and KITY “Power 93” (now Regional Mexican "Que Buena" KROM 92.9).

In March 2000, Waterman reached a deal to sell KTFM and KTSA to Infinity Broadcasting for $90 million, as Waterman was looking to focus solely on its television assets.[6] That same year, the Top 40 market would be shaken up by the arrival of a move-in at the 98.5 FM frequency. KBBT was launched as "The Beat", with a Rhythmic format featuring hip-hop music. The Beat quickly climbed up in the ratings.

In August 2001, KTFM decided to challenge KBBT by changing from Mainstream Top 40 to a more rhythmic-leaning sound as "Wild 102-7". KBBT had the hip hop audience, and KTFM started to see its ratings decline.[7]

K-Rock and Jack FM

On October 24, 2003, KTFM dropped the Top 40 format after 17 years and flipped to Mainstream rock as "102.7 K-Rock." The call letters became KSRX. The first song on "K-Rock" was "Welcome to the Jungle" by Guns N' Roses.[8][9] But 99.5 KISS-FM was the veteran rock station in San Antonio and KSRX was unable to compete for rock listeners.

On January 1, 2006, after a brief "Free FM" stunt, KSRX became "102.7 Jack FM." It changed its call letters to KJXK started playing adult hits with no disc jockeys, just the quips from the voice of Jack. The first song on Jack FM was "Get Ready for This" by 2 Unlimited.[10]

Changes in Ownership

In August 2006, CBS Radio sold KJXK and KTSA to Border Media Partners (BMP) for $45 million.[11] Meanwhile, BMP revived the KTFM calls in 2005 on 94.1 FM, which has since reverted to its well-known Top 40 format.

On October 14, 2013, BMP sold KJXK and the rest of its San Antonio cluster to L&L Broadcasting (now Alpha Media) for $31 million.[12] The transaction closed on January 31, 2014.[13]

On January 7, 2016, at 4 p.m., after a half-hour of "goodbye"-themed songs (ending with "Someone like You" by Adele), KJXK briefly stunted with country music. During the stunt, it kept the “Jack FM” name, but included barnyard sounds in the bumpers and branded the Facebook page as "102.7 Yeehaw FM". As 94.1 KTFM was stunting at the same time, this led listeners to believe KTFM was moving back to 102.7 FM. However, at 5 p.m., “Jack” returned, and the country music was revealed to be a publicity stunt.[14]


  1. ^ "Miraculous". Express and News. January 17, 1970. p. 1. Retrieved July 17, 2021.
  2. ^ a b FCC History Cards for KJXK
  3. ^ Radio-Locator.com/KJXK
  4. ^ "Miraculous". Express and News. January 17, 1970. p. 1. Retrieved July 17, 2021.
  5. ^ Billboard Vox Jox News, p.26. Billboard. April 15, 1972. Retrieved 2011-08-21.
  6. ^ "CBS company to buy KTSA and KTFM radio stations". San Antonio Business Journal. March 28, 2000. Retrieved July 20, 2021.
  7. ^ Garcia, Gilbert (November 13, 2003). "Airwave shakeup leaves little wiggle room in the crowded rock field". San Antonio Current. Retrieved July 20, 2021.
  8. ^ http://www.americanradiohistory.com/Archive-RandR/2000s/2003/RR-2003-10-31.pdf[bare URL PDF]
  9. ^ http://www.americanradiohistory.com/Archive-RandR/2000s/2004/RR-2004-01-02.pdf[bare URL PDF]
  10. ^ http://www.americanradiohistory.com/Archive-RandR/2000s/2006/RR-2006-01-06.pdf[bare URL PDF]
  11. ^ "CBS to Sell Two Texas Properties to Border Media for $45 Million". RadioWorld. August 22, 2006. Retrieved July 20, 2021.
  12. ^ "L&L Broadcasting Acquires Border Media Stations For $31 Million". All Access. October 14, 2013. Retrieved July 20, 2021.((cite web)): CS1 maint: url-status (link)
  13. ^ "Consummation Notice". Federal Communications Commission. February 3, 2014. Retrieved July 20, 2021.((cite web)): CS1 maint: url-status (link)
  14. ^ Jack-FM San Antonio Stunting With Country Music?

Coordinates: 29°25′08″N 98°29′02″W / 29.419°N 98.484°W / 29.419; -98.484