Codan NGT 2010 RF Technical & Service Manual page 90

NGT—Brief description (2010)
The transceiver uses double conversion in both the Receive and Transmit modes. Only
the 455 kHz sideband filter and the local oscillators VCO and REF OSC are common to
both modes of operation.
The signal routing is determined by switching and control voltages according to the
selected mode.
58 NGT Transceiver System Technical Service Manual