modem IC's

[Darrenmac]

Hey does anyone know of any good single chip modem IC's? I am not looking for the modem/radio all in one jobs but a modem that I can interface into an existing radio for my pic to use for long range data comms

[Ron Marcus]

Hey does anyone know of any good single chip modem IC's? I am not looking for the modem/radio all in one jobs but a modem that I can interface into an existing radio for my pic to use for long range data comms

I used an Exar 2211 for a FSK receiver up to 5 Kbaud. You can use a 2206 for a generator, or generate the FSK signal in software.The 2206 requires a 10 volt supply, which is inconvenient. It worked quite well, and as it was frequency shift, instead of phase shift, if the transceivers detuned slightly, there was no problem. If yopu have the bandwidth, you could run them up to 28k without much hassle.

Ron

[Darrenmac]

Know where to find any routines for generating FSK or can you point me in the right directions for writting the code?