SECTION 4
TECHNICAL DESCRIPTION
4.1 RECEIVING CIRCUIT OPERATION 25
4.1.1 Antenna Switching Circuit 25
4.1.2 High Frequency Amplifier Cir cuit 25
4.1.3 1st Intermediate Frequency Amplifier Circuit 25
4.1.4 2nd Intermediate Frequency Amplifier Circuit 25
4.1.5 Low Frequency Circuit 26
4.1.6 Squelch Circuit 26
4.1.7 Low Frequency Treatment Circuit (CPU AF
Board) 26
4.1.8 WX Alert Detection 26
4.2 TRANSMITTING C IRCUIT OPERATION 26
4.2.1 Microphone Amplifier Circuit 26
4.2.2 High Frequency Power Amplifi er 27
4.2.3 APC Circuit 27
4.2.4 Antenna Mo nitoring Circuit 27
4.3
PLL CIRCUIT OPERATION 27
SECTION 5 MAINTENANCE
5.1 GENERAL 30
5.1.1 How to contact Raymarine 30
5.2 PREVENTATIVE MAINTENANCE 31
5.3 ALIGNMENTS AND SERVICE 31
5.3.1 Test Equipm ent 32
5.3.2 PLL Adjustm ent 32
5.3.3 Frequency Adjustment (TRANS MITTER) 33
5.3.4 Modulation Adjustment (TRANSMITTER) 33
5.3.5 Power Output Adjustment 33
5.3.6 RF Sensitivity Adjustment (RECE IVER) 33
5.3.7 Weather Alert Frequency Adjustment
(RECEIVER) 34
5.4 TROUBLE SHOOTING GUIDE 34
5.4.1
Master Reset 34
SECTION 6 PARTS LIST & DRAWINGS
6.1 PART LOCATION LIST 37
6.2 ASSEMBLY DRAW ING 43
6.3
SCHEMATIC DRAWING 45
SECTION 7 APPENDIX
7.1 VHF MARINE CHANNEL USAGE GUIDE 52
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