hey, that pdf is a great confirmation of the problems that I had with the unit described at system-high.com! It even mentions that the modulators are mono....
You have to spend major bucks to make this work on channel three. The modulator is the right approach. And if it is terribly important to have stereo sound, both Channel Plus and Channel Vision have stereo modulators, although they are pretty pricy.
Ernie
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw