[Discuss-gnuradio] bell 202 modulation

[Matteo Campanella]

Hello, I am trying to find the best way to implement a bell 202 modem in
gnuradio. The problem I am facing is that I need to produce two tones, one
for mark and one for space, and I have to switch from one to other
depending on which symbol I am sending. The duration of the tone (or tone
switch) must be set exactly according to the baud rate of 1200 I have to
produce.

I was thinking to use the nco class to generate the tones, and to output n
samples per symbol at a certain fixed sample rate that would be enough for
the 1200 baud, let´s say the standard audio 48000.

Has anyone better suggestions to work this out?

MC