can the tv out port be remapped?

[drspastic]

hi, has anyone tried to remap the tv out to provide a baseband signal? i want to use it to generate a phase shift modulated signal at 3.5 mhz or above. not a complex waveform, just slow psk31. i hope to then run the output signal into a small booster and use it to provide a telemetry beacon for gps data.