Hi all,
         which would you all prefer as a way to frequency-shift your TX ?
With frequency shift I mean many steps, separated by a fraction of an Hertz.
The first two possibilities that come to my mind are an audio output from the
sound card (requiring then a mixer to bring the tone to the wanted freq.),
or a binary value output from, say, the parallel port, which then would require
a small external board with a DDS or a microcontroller to drive the TX.

No linearity requirements will be needed. I need your input to not start in a
false direction.    TNX for any advices.

73  Alberto   I2PHD