Here is a chart that will show you want the above members are talking about. If you have old Sanwa servos they were sold here in theUSunder the name Sanwa but were sold with Airtronics radios. Later they were sold under the label of Airtronics. If the connectors have the 3 splines on them you can convert them for use with your Futaba radio with a little work.First, you will need to rewire the connectors. The old Airtronics servos had the positive on the outside of the connector while the rest of the world had the positive on the middle connector (see the chart). Unfortunately the old wires used weren't red and black, but instead they are all black, but the positive wire will have a white stripe on it. What you will need to do is use the point of an X-acto knive or a small jewelers screwdriver to lift the small tab on each wire of the connector. Pull out both the positive wire (with the white stripe) and the middle wire and switch them. Now that the servo is rewired for use with the Futaba radio you can shave off the splines on the connector. Once you have those shaved off you can now plug in the servo to the Futaba receiver. Just be advised is there is now nothing that will prevent you from plugging it in backwards. As you plug them in you will need to ensure they are plugged in properly. An easy way to ensure this is to plug in the battery (which should have a tab on it to prevent plugging it in backwards) and this will show you where the negative leads on the receiver are. Plug your servos in with the negative wires in the same position as the battery and you'll be fine.

Ken