Radio air checks are normally used by radio talent and program directors to go back and listen to the talent’s performance. Many times these air checks are recordings of a DJ’S shift but was “telescoped” so it only recorded the time that the talent’s microphone was turned on (aka ‘open’). Air checks were also collected by radio fans that wanted to either record a DJ they liked or perhaps event grab that hit song they can listen to later.
Mike Schweizer was a bit of a radio fan boy in his early years. Later on he became a radio engineer specializing in remote broadcasts and working as an engineer for stations like KUSF, KYA and KSFO. As a kid and through his adult life, he made recordings of stations and collected hundreds of reels of tape. Unfortunately his life was cut short and passed away in 2011. Before he passed, he transferred a good number of these airchecks to digital. I have many of these up at my site that you can listen to. Since I published these some years ago, Internet Archive has recently copied these recordings and has put them up there.
I should say that not all of these were recorded by Mike, it seems that there are a handful that were recorded by others that have snuck in here. If you find that one of those are yours, please drop me a note and I can remove it if you deem it necessary.