Lane,
That would depend on which 1197 transducer you have. We added additional shielding to this transducer some time back so the one you have may or may not have that added shielding. Take a look at the numbers and letters printed on the 1197 transducer cable. These should be within the first few feet of the connector and post back than we could give a better answer. It could be that it is the one with the added shielding which means it is the same as the one that came with your 1198c Si unit and it would not make a difference either way.