There are a few thousand airchecks on the radio museum website. There are no restrictions to accessing them.
In the beginning, I decided to use Real Player as the default player on the website -- if it's good enough for Uncle Ricky Irwin's magnificent ReelRadio.com, then it's good enough for the museum.
Over time, however, more and more visitors complained about Real Player, so I decided to start converting everything over to straight MP3 links (or M3U for multi-part files) that would play on any (or virtually any) MP3 player. It's a long, slow, laborious process (thanks, volunteers!) (why yes, I am being sarcastic) but it will eventually get done 100%.
But, as I said, there are thousands of airchecks on the website. Many of them still require Real Player. I am on the website every day and I'm checking links constantly. I just jumped around and tried about six different RA, RM and RAM links, and they all fired off and played just fine on my PC. Haven't tried them on a Mac today, but will.
So, krth101, is there anything in particular that you were trying to listen to that didn't work? It could be that I simply screwed up and the link is broken -- and if that's the case, I'll have our team of volunteers get on it right away.