First thing I would do.......
Use the 4DTV and Pick a Sat, and peak Signal.
In the FTA Receiver, set the correct LNB L.O., and Diseqc Switch Port, and select a known Active Transponder, check for Quality Strength. If the 4DTV is controlling the LNB Polarity, switch between Channels 1 and 2 on the 4DTV to change the polarity. The 4DTV polarities are opposite that of the FTA Receivers, so if you are trying to lock a Horizontal TP in the FTA Receiver, you should start with the 4DTV on a Vertical Channel.
How do you have the Slave Kit wired?