The "Data in" is a misnomer - do not send digital signals down this, send a modem output (audio)
Most mic inputs are happy with about 50mV of signal, most line outputs (what sound card packet uses) are around 1v. going to need an attenuator.
speaker out will work, just adjust the radio volume. "audio out" line is better b/c has fixed volume independent of volume knob, may want to play with that instead. All lines available at the front panel 8pin modular, check the manual for pinout.
Scanner 2 (antenna 2)
Ham radio with lots of crazy buttons
Fire department radio, a pager and a baby monitor
oh and i have a clock radio that picks up cuba