When do you get Schneider's Codec frequency?

Solution 1:

You're supposed to get a call from him on the third floor of building 1, (supposedly it happens in a random room) but it doesn't always happen. I've seen people say this is a bug, but it's hard to say.

Sometimes he doesn't call you until you've already tried dialing his codec frequency, which has lead some to believe that you're supposed to get his frequency from the (original) game manual. There's certainly some precedent for this; in other games certain characters' frequency information was hidden on the CD/DVD case or in the manual.

Update: As it turns out, there's a really obscure way of getting the call from Schneider. While in the room where the west elevator is on the third floor, open the codec and tune past 120.79. This is the trigger for getting the call. Credit to Powerlord who discovered thisthrough a bit of luck and crazy experimentation.