I would like to transmit digital audio via radio. I have the radio side sorted out ok. I have a transciever that is capable of 9600 data via the discriminator (RX) and direct drive (TX).
My guess is to use something like the MC3418 to encode the audio into a digital signal that can be feed into my transmitter.
I do not know where to find such a chip in canada. Maybe another delta modulator exists or a better (still inexpensive) way of doing it.
Maybe I should buy a $20 GE cordless phone and see what I can remove from the device.
The required baud rate is dependant on the encoding method. 9600 baud should be adequate for voice grade communications. The MC3418 actually suggests this in their application notes.
I work at a University and the radios are licensed for experimental use. Any mode is permitted. I'll probably use a 5khz voice channel although North America is moving towards tighter channel spacing for land mobile. Most of the newer kit seems to be 2.5/3khz wide.
I found someone that used the MC3418 and pushed their voice up a submersible cable at 9600baud with telemetry data.