Utah has long had 2 PBS stations: KUED-7 from the University of Utah in Salt Lake City and KBYU-11 from BYU in Provo. Both are distributed throughout the region on an impressive network of translators and repeaters and have been for decades.
KUED has basically been the "secular" station; the one that's like a typical PBS affiliate. KBYU is the one that tailors programming to the large LDS community in the state. They air PBS children's and educational programming, but also LDS church speeches, discussions and programming.
Now that the BYU channel (also owned by the LDS Church) is available to cable and dish subscribers, some of the LDS programming has migrated to that channel. This allows time for KBYU to air some other "wholesome" older shows that are not carried elsewhere in the market. As the truly devout LDS church members eschew newer shows and look upon older ones as being more virtuous, they feel that they are serving that segment of the public by scheduling such programs. Personally, I like them too and did watch a few episodes myself (as well as Britcoms on KUED).
Technically, I suppose you could call KUED the "primary" PBS affiliate and KBYU the "secondary" affiliate. However, culturally - in that market - no one would think of them in those terms.