Multiplexer signal? - Signal

[gugges]

I sat and read the Elektor magasine and came to realise that all channels in the radio are generated separatly and then put thru a multiplexer that continues to the amplifyer(antenna).

From what I can understand this signal before the amplifyer or more accurate, the signal from the multiplexer is the same signal as the "pupiloutake"?! this would enable me to use the signal to the computer for FMS?!
Is anyone fimillar with this?

Sorry for the poor english...