Where are people getting all these vintage radio airchecks from?

[Daniel D. Teoli Jr.]

Some sellers on eBay say they have thousands of hours of radio broadcasts on CD. Are there radio archives where you can download for free? 

 

Some have old country from the 40's. Others rock and pop from the 70's. Here are 2 samples:

 

https://www.ebay.com/itm/193199877919

 

https://www.ebay.com/itm/130358456455

 

Dr. Demento has an archive where you can stream for $2 a show. (I think.) I got a R/R tape the other day in an eBay lot that had a Dr. Demento show that was previously on the reel but title had been scratched out and audio copied over with garbage. 

 

I had forgot about Dr. Demento. I used to listen to him in the 70's / 80's in my darkroom in L.A. Seeing the R/R tape reminded me of him.