Codan 9780 - Page 4

Table of contents
ii HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual
Programming cable....................................................................................2-13
Cloning cable.............................................................................................2-14
Options................................................................................................................2-15
3 Brief description
General..................................................................................................................3-2
Control and switching...........................................................................................3-3
Synthesiser............................................................................................................3-4
Receive path..........................................................................................................3-5
Transmit path........................................................................................................3-6
4 Technical description
Control and supply voltages .................................................................................4-1
Power on......................................................................................................4-1
Power off.....................................................................................................4-2
Supply voltages ...........................................................................................4-2
Receive/Transmit switching........................................................................4-4
Receiver................................................................................................................4-5
Input low-pass filters...................................................................................4-5
High-pass filters ..........................................................................................4-5
RF amplifier ................................................................................................4-5
LPF and first mixer .....................................................................................4-6
45 MHz band-pass filter..............................................................................4-6
Second mixer...............................................................................................4-6
Noise limiter................................................................................................4-6
455 kHz filter and IF amplifier....................................................................4-7
Demodulator................................................................................................4-7
Automatic gain control................................................................................4-7
Voice mute ..................................................................................................4-9
Volume control and audio output amplifier..............................................4-10
Low voltage Tx inhibit..............................................................................4-10
Transmitter exciter..............................................................................................4-11
Microphone amplifier/compressor............................................................4-11