[ARC5] J-17 and J-17A/ARC-5

[jcoward5452 at aol.com]

Group,
 I have a J-17/ARC-5 junction box that I plan on adding in to my setup along with an RL-7 interphone. I just watched the J-17A/ARC-5 auction on the eplace and was interested in the photoes showing a switch to select RL-9/AM-40/AIC or RL-5/RL-7.From the photos it appears to be switch an r/c circuit.Is this correct and why?
 Thanks,
             Jay