Wow, Greenland! Can you post some text samples of the raw output section? (I could even host them for you on my site if you want. Fire me a PM message if you're interested.)
What's your '20, by the way?
"I'd start by running a simple patch cable from the line-output jack on your Sony to the microphone input on your computer's sound card."
*waves hands* NOOOOO!! No no no no no!! Whatever you do, NEVER connect a line-level output to the microphone/phono input (reddish-pink) unless you want to royally screw up your sound card and probably mess up the radio, too! Use the line-in jack (yellowish-green) instead. Only connect microphones to the microphone inputs.
I actually learned that the hard way one time with an 8-track player and a Sound Blaster microphone input.