I do not understand the wire conenctions located under the base that face in opposite directions? What is the light green plastic loop for? Also,the slip-on connections are not the most convenient. Where do I get replacement slip-on connections
Note this question was asked in respect of an RJ series straight key, but it applies equally to Bencher paddles, which have a third connection.
The plastic loop is a cable clamp, that’s all. Remove the screw, slip your cable through the loop, then screw it back onto the key base. With the cable clamped, any strain will be on that loop and not the connections, which could pull loose if the cable is not secured by the clamp.
The slip on connectors are a standard automotive part and you can get them at RadioShack if you need replacements. They are crimp type connectors, but I usually solder them as well. Just insert the wire into the sleeve on the end and mash it flat with pliers if you don’t have a genuine “crimping tool.”
The orientation of the connectors is meaningless and can be changed by loosening the screw or nut slightly and turning the lug around to where you want it.
In a straight key you only have two wires to worry about– “hot” and “ground.” Usually the “hot” side of the key cable is connected to the lower front contact, which is the connector closest to the knob. The other is just connected to ground through the base of the key. The usual arrangement– hot lower front contact– is important with older, tube type radios that have substantial voltage on the key line. Only the lower front contact is exposed, so your risk of getting a burn from it is very slight.
The connectors are actually meant as a convenience, but you don’t have to use them. You can solder a wire directly to the lugs if you want, or remove the lug and wrap the wire around the screw.