If this is the E.F.Johnson KW of which you speak.............
http://bama.edebris.com/manuals/johnson/matchbox/With mine & owl..............no jumpers to either connection. Manual states to connect single wire transmission lines to terminal designated "Single Wire". The remaining feed-thru terminal must be grounded to the ground terminal above it during operation on 80, 40, 20 meters and left ungrounded on 15, 11, & 10 meters.
There is a ground connection............stud with nut. Best connect this puppy to a ground.
YMMV
Craig,