If the 730 has a ignition sensor modification and the 830 did not, it may be the issue. Just a thought. I have used a couple of the dual band radios as single band and they were reprogrammed but the chip caused a issue with it. It would cause a error, but would still work. On the TK*30 Series radio's, to do the dual band modification, the give you a different chip. On the newer TK*90 Series radio's you do not need a chip upgrade to do the dual band mod.
David...