User Manual Part 1

5
SECTION 5 CIRCUIT DESCRIPTION........................................................................... 44
5.1 GENERAL TRANSCEIVER DESCRIPTION...................................................... 44
5.1.1 INTRODUCTION .......................................................................................... 44
5.1.2 PC BOARDS .................................................................................................. 44
5.1.3 CIRCUIT PROTECTION (FUSES)............................................................... 45
5.1.4 ANALOG MODE........................................................................................... 45
5.1.5 PROJECT 25 DIGITAL MODE .................................................................... 45
5.2 VHF BOARDS....................................................................................................... 46
5.2.1 VHF RF BOARD ........................................................................................... 46
5.2.1.1 RECEIVER............................................................................................. 46
5.2.1.2 SYNTHESIZER...................................................................................... 48
5.2.1.3 TRANSMITTER ....................................................................................49
5.2.2 VHF 20-WATT PA BOARD ......................................................................... 50
5.2.2.1 VARIABLE ATTENUATOR ................................................................ 50
5.2.2.2 PA RF DEVICE (Q6) ............................................................................. 51
5.2.2.3 FORWARD POWER DETECTOR, ANTENNA SWITCH, LOW-PASS
FILTER................................................................................................... 51
5.2.2.4 POWER CONTROL............................................................................... 51
SECTION 6 ALIGNMENT PROCEDURE ..................................................................... 54
6.1 GENERAL ............................................................................................................. 54
6.1.1 INTRODUCTION .......................................................................................... 54
6.1.2 TUNE SOFTWARE ....................................................................................... 54
6.1.3 PCTUNE VERSION REQUIRED ................................................................. 55
6.2 MAIN SCREEN ..................................................................................................... 55
6.3 MENU BAR DESCRIPTION ................................................................................ 57
6.3.1 FILE MENU ................................................................................................... 57
6.3.2 RADIO MENU............................................................................................... 57
6.3.3 TRANSFER MENU ....................................................................................... 57
6.3.4 TOOLS MENU............................................................................................... 58
6.3.5 HELP MENU ................................................................................................. 59
6.4 TUNING PROCEDURE........................................................................................ 59
6.4.1 CONNECTING TEST SETUP ...................................................................... 59
6.4.2 STARTING AND CONFIGURING PCTUNE.............................................. 60
6.5 DIGITAL PERFORMANCE TESTS ....................................................................60
6.5.1 GENERAL...................................................................................................... 60
6.5.2 RECEIVE TEST SETUP................................................................................ 61
6.5.3 RECEIVE SENSITIVITY TEST ................................................................... 61
6.5.4 TRANSMITTER TESTS ...............................................................................61
6.6 ANALOG PERFORMANCE TESTS.................................................................... 62
6.6.1 GENERAL...................................................................................................... 62
6.6.2 RECEIVER PERFORMANCE TESTS ......................................................... 62
6.6.3 TRANSMITTER PERFORMANCE TESTS................................................. 63
SECTION 7 PARTS LIST ................................................................................................ 65
SECTION 8 SCHEMATIC DIAGRAMS AND COMPONENT LAYOUTS ............... 102