DRA-MIX-MUX REV1 & REV2 Jumper Settings:


JU1 (yellow) A = 1200 - B = 9600 receiver baud rate delivered to the board from the radio.

JU2 (green) A = 1200 - B = 9600 receiver baud rate delivered to sound card 1 (SC1 - DIN-6 Jack)

JU3 (blue) A = 1200 - B = 9600 receiver baud rate delivered to sound card 2 (SC2 - DIN-6 Jack)

Both sound cards and the radio can be set to either 1200 or 9600 baud receiver audio.  

I don't have an opinion as to setting these jumpers differently from one another.  In other words, 
I don't know if it's possible to set the radio to 9600, then set one sound card to 9600, and have 
the second sound card or modem set to 1200.  I suppose it's possible, but I don't know what to 
expect as to how it would operate or perform.  Most people use 9600 audio even for 1200 connections.