Airtronics and Futaba connectors are alike as far as the polarity and signal wires are concerned, though there is a slight physical difference. You have to
shave off the lip on the Futaba servo connector before it will fit into the opening in the Airtronics receiver. Be sure the color wires match, though nothing
happens if you reverse the plug, only that the servo will not operate. Luck!
By the way, the RDS8000 manual is one of he best around.