|City of license||La Porte, Texas|
|Broadcast area||Greater Houston/Golden Triangle|
|First air date||2005 (on current tower)|
|Callsign meaning||K Houston JacK (former format)|
|Former callsigns||KTDD (1990-1991)
KVST (1991-2005, as "K-Star Country")
KUST (3/2005-5/2005 as "TV 103" stunt)
KIOL (2005-2007 as "Rock 103.7")
|Former frequencies||103.5 MHz|
|Owner||Educational Media Foundation|
|Sister stations||KXAI, KZAR|
KHJK (103.7 FM, "Air 1") is a Christian rock-formatted radio station serving the Houston and Beaumont, Texas, areas. It relays the satellite delivered Air 1 format by owner Educational Media Foundation.
KHJK-FM previously operated as KVST, "K-Star Country 103.7", which was licensed to service Montgomery County, Texas, prior to being purchased by Cumulus Media in 2005. Originally owned by Ben Amato of Conroe (who sold his chain of grocery stores around that area to finance the radio station), it signed on as KVST in Huntsville, TX on 103.5; however, interference from 103.5 in Buda, TX (Oldies 103.5 KEYI Austin, now BOB-FM KBPA) caused the station not to reach down to the intended audience of Conroe and a look at a move in frequency was done. Amato moved the station's frequency up one channel to 103.7, and also physically moved the tower site south to Willis, Texas. This resulted in an excellent signal in Conroe, Willis, and the exploding community of The Woodlands, Texas. However, the signal was all but lost back in Huntsville, which was solved by Amato bringing to a new station licensed to Huntsville to simulcast KVST. That station became KUST at 99.7 Mhz. Ironically, in 2005, Cumulus Media purchased the license for 103.7 and once KVST relocated to La Porte, KUST made the exact same journey down interstate 45 that 103.7 had made before it. As a part of the move of 103.7, KUST switched call letters with KVST, resulting in the current KVST Willis, Texas and the short lived KUST La Porte. These calls were only used for the "TV 103" stunt format utilized while Cumulus prepared for the move of 97.5 KIOL's rock format and call letters to the debuting 103.7.
In 2005, Cumulus moved 103.7 to its current location in Devers to service the Houston & Golden Triangle areas.
On August 30, 2007, the Houston Chronicle reported that KIOL would be switching to the Jack FM format at 10:37 a.m. the following day, and adopting new call letters, KHJK . The final songs on "Rock 103.7" were "Mary Jane's Last Dance by Tom Petty, "Cold As Ice" by Foreigner, and "Fire" by Jimi Hendrix, while the first two songs on "Jack" were "Jumpin' Jack Flash" by The Rolling Stones" and "Let's Go Crazy" by Prince."
On May 6, 2009, KHJK shifted from adult hits to adult alternative as "103-7FM." 
As part of a prepackaged bankruptcy filing, the lenders took over the license of four Cumulus Media Partners stations; two in the Kansas City metro area (KCHZ and KMJK) and the two rimshot signals in the Houston metro, KHJK and KFNC in November 2011. Station broker Larry Patrick became majority owner and set out to sell the stations to recover the value for the lenders. After the filing, Cumulus continued to program the stations under LMA. While Cumulus could have purchased the stations back, the highest bidder for KFNC was David Gow, owner of KGOW (1560 The Game) and the highest bidder for KHJK was Educational Media Foundation, who programs Christian AC and Christian Rock formats.
Between In The End and Closing Time, the announcer gave this goodbye message :
"Houston, thank you. It's been an amazing ride. Steve, Donna, and the entire 103-7FM crew want to say thanks for being there for us. Attending our events, coming to our shows, and just for listening to Houston's adult alternative, 103-7FM. It's been our pleasure serving you some of the best new music out there and playing music you can't hear anywhere else but 103-7FM. You are some of the best listeners we could have ever asked for, and we'll miss you. Thanks again. And are you hiring?"
- KTDD - 05/03/1990
- KVST - 07/22/1991 (K-Star Country)
- KUST - 03/30/2005
- KIOL - 05/23/2005 (Rock 103-7)
- KHJK - 09/01/2007 (103.7 Jack FM, 103-7 FM, Air-1)
Cumulus Broadcasting began upgrading its stations to HD Radio broadcasting in 2005. One of the first ten stations to be upgraded was KIOL. The station had been simulcast on KRBE HD-2, but this was replaced by a feed of the True Oldies Channel in June 2012.
- Harnett, Mary Beth (2006-04-24). "Harris Corporation Announces Multi-Deal Agreement as Exclusive HD Radio(TM) Supplier to Cumulus Broadcasting". EE Times.
- 103.7 changes format on Houston Chronicle 29-25
- Query the FCC's FM station database for KHJK
- Radio-Locator information on KHJK
- Query Nielsen Audio's FM station database for KHJK