This lead is used for connecting the EX-704 Programmer to some of the radios that the EX-704 Programmer is used for and also as the connecting lead between some radios and the EX-1196 level converter when programming from a PC.
Assemble as shown diagrammatically below, the sleeve connection of the jack plug going to pin 4 of the modular plug and the ring of the jack plug to pin 7 of the modular plug. The tip connection of the jack plug is not used.
Don't forget to put the cover of the jack plug on the cable before soldering (I've forgotten too many times myself)! The modular plug is shown with the connection pins toward you, the locking tongue away from you.