XEPRS (formerly XERB featuring Wolfman Jack) was known as "The Soul Express" in 1971, featuring big name air talent as Roger Christian (pictured) and Brad Edwards (both jumped over from KGBS) and playing "oldies but goodies" from Midnight to 3am (brokered) was Art Laboe (pictured).
Ted Quillin also was part of "XEPRS" during the soul format in 1972, after leaving country KFOX.
The XEPRS transmitter was in Rosarito, south of Tijuana in Baja California, Mexico.
Some jocking indeed took place from Rosarito from their ocean-view "board."
(Edwards, Christian, and Quillin mostly jocked from the 6th and Western in Los Angeles studios)
Sometimes pre-recorded taped shows (such as Laboe) were played from that site, too, on the reels seen in these photos.
The powerful "border radio blaster" could be heard in 7 states, we were told.