The KPIX obit was a bit skimpy on McElhatton's radio career. Maybe DJ or somebody with a long memory can give us a rundown of all that. Not being a KCBS listener until the late 70s (when Dave was already on KPIX), I missed it. I've heard that he was the Music Til Dawn late night DJ on KCBS for a number of years (KNX in LA had the same name for it's all-night show in the MOR era).
Then I heard he moved to morning drive, where he was initially a DJ, of course - competing with Sherwood, among others. When KCBS became an all-news station (1968?), Dave became morning anchor until his move to TV (about 1977?).
When Dave's TV career is discussed, it's always pointed out that he was hardly a typical anchor -being rotund and balding. I recall that KPIX actually exploited that to some extent - publicizing Mac as the antidote to all the "Broadcast News" style blow-dried anchor-clones of the 70s.
Dave deserves the credit for being the anchor that finally put a crimp in Van Amburg's armor. Shortly after joining KPIX, McElhatton became the first competing anchor in about a decade to seriously challenge KGO-TV in the ratings.