LUCAS "Opus" Electronic Ignition: Description
Lucas Oscillating Pick-Up System (OPUS) electronic ignition includes an amplifier unit that is mounted separately or on distributor. See Figs. Fig 1and Figure.
A ballast resistor unit is used on all Jaguar models, while a ballast resistor wire is used on other models. Other components include an ignition coil, a drive resistor (if used), and the breakerless distributor.