Furuno FCV-1200L Service Manual page 19

terminals when the external transceiver unit (ETR) or EX mode is selected.
Gain and TVG voltage
When external transceiver unit is selected on the menu, Gain and TVG data, which are set on the
control panel, are derived from the CPU on the MAIN board to the CPU on the EXIF board and
converted into the analog voltage by the D/A converter.
The analog Gain and TVG voltage is supplied to the receiver amplifier in the ETR unit and control
the amplitude.
Gain and TVG control voltage are outputted from the EXIF board. The CPU on the EXIF1 board
generates the Gain and TVG data to the D/A converter in accordance with the GAIN/TVG data sent
by the CPU on the MAIN board.
16