Add Opt 001 to Agilent 33220A ?

[JohnPi]

I scooped an Agilent 33220A locally, but it doesn't have the external reference input capability -- those BNC holes at the rear are dummies.

Does anyone know if manually adding BNCs is all that is needed ? -- are the circuits associated with it (schematic shows a coupling transformer, and some detection circuits) populated on a non-Opt 001 board ? Any photos of the inside ?

[JohnPi]

Never mind -- I see in the service manual that this option adds another small board inside the instrument.