Hi, I recently purchased an 1870f and a tm260 transducer. I can't find an option for my transducer. I tried several settings from the transducer menu, but only the 50/200-1T and 50/200-12M give me bottom discrimination and accu-fish. I don't know if the readings are correct though, and whether I should manually change some of the settings to suit the tm260. Any help is welcome.