Should the Temp Calibration function within the System menu affect the temperature sourced from a transducer connected to an ETR-6/10N sounder? It certainly calibrates temp readings from my DT200 N2K transducer when I select that as the data source in the Setup routine.....but it seems to have no effect when I select the sounder as the temp source. I am getting a temp reading via the sounder....but it is around 10C too low & constant, whatever the calibration adjustment.