Thanks, 232 Cap-tain....I was off reading the "AMA" forum (interesting stuff going on over there)....and didn't answer the question...
The 8103 manual references using programmable mixes 5 and 6 for dual elevator, as it permits mastering of the source channel trim function. Putting the trim lever of the elevator into the channel you mix TO.
It's unfortunate that JR DOES NOT put that mix in their manuals; it's being used more and more...maybe in the new 9X ???