Codan 8528 Series - Page 8

vi Table of Contents 8525B/8528 Technical Service Manual
Issue 6 Publication No: 15-02036
6.3 Dismantling and Re-assembly............................................................................6-9
6.3.1 General ............................................................................................6-9
6.3.2 Top and Bottom Covers ..................................................................6-9
6.3.3 Circuit Board Removal....................................................................6-9
6.3.4 PA and Filter Assembly ................................................................6-10
6.3.5 Replacement of PA Transistors.....................................................6-11
6.3.6 Replacement of Escutcheon or Switch Substrate..........................6-12
7 Adjustments
7.1 Introduction ........................................................................................................7-1
7.2 Channel Addition (EPROM Replacement)........................................................7-1
7.2.1 Channel Addition, Programming P Channels (8528)......................7-2
7.3 Preset Adjustments.............................................................................................7-5
7.3.1 Test Equipment Required................................................................7-5
7.3.2 Voltage Regulators..........................................................................7-6
7.3.3 Crystal Oven....................................................................................7-6
7.3.4 VCO Adjustments (RF Mixer and Dual Synthesizer PCB) ............7-6
7.3.5 45MHz IF Alignment—Receive .....................................................7-7
7.3.6 1650kHz IF Alignment....................................................................7-7
7.3.7 45MHz IF Alignment—Transmit....................................................7-7
7.3.8 Highpass Filters...............................................................................7-9
7.3.9 Noise Limiter.................................................................................7-10
7.3.10 Frequency Adjustment (USB).......................................................7-10
7.3.11 Frequency Adjustment (LSB)........................................................7-10
7.3.12 Mute Adjustments .........................................................................7-11
7.3.13 PA Adjustments.............................................................................7-11
7.3.14 Output Power.................................................................................7-11
7.3.15 Options SD, SDE and SDEM........................................................7-13
7.3.16 Option TD .....................................................................................7-13