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On the DMX741 connect the jumper from the ku lnb(the orange at the end) to the port that says lnb. Then of course the other to your receiver. Set your settings so that the C-Band stuff is on port one in your DiSEqC setting and the Ku is port 2. Turn 22khz on.
I found it to work better using an external 4 port switch. I just ran a longer cable from the ku side to the ext. switch to port 2 on it(doesn't have to be on external one) and where it says to receiver, that will be your C-Band side, run that too port 1 of external switch. If you do this set up with external switch turn off 22K.