f40ph - that would make lots of sense. 173.225 from portable to extender - and 173.225 from extender to portable. The extender probably has a sensing mechanism that gives priority to messages from the portables versus messages from the extender.
It is essential that the repeater be turned on just before the officer exits the vehicle, and turned off when the officer leaves the scene. Repeaters must not be left on when not required. Leaving a repeater on needlessly will cause unnecessary delays for other officers, noise and garbled traffic reception at dispatch, and may cause uncontrolled misdirection of trffic to the wrong officers and dispatchers.