The above is not an air check but does have some radio content. From an interesting reel to reel tape I found that may have been a pre-edit for an actual radio program. Below is the sheet that I found with the tape. I have omitted most of the Stones and Dylan content. The air checks on this site are exclusive but as this is not an air check some of this material is available elsewhere.

The tape features early Grateful Dead, Jefferson Airplane and others.  Also  counter culture luminaries such as Paul Krassner, Neal Cassady and Ralph J Gleason can be heard. DJ’s Tom Donahue and Larry Miller from the legendary KSAN are referenced below and can be heard briefly on the clip.

Note – I have more info about the clip courtesy of jmcinnis and chicofishead at the Steve Hoffman Forum :

This is a portion from ‘What Was That or Suddenly Lost Summer 1966-1976’ special broadcast over two days by KSAN San Francisco in 1976. A retrospective look at the decade with music & interviews. This looks to be production notes?