Section 1 1160kb Introduction

Section 2 229kb Block Diagram

Section 3 313kb Brief Description

Section 4 2227kb Technical Description

Section 5 Operating Instructions. Manual states to refer to seperate user booklets.

Section 6 589kb Maintenance

Section 7 633kb Adjustments

Circuit diagrams apply to all radios unless otherwise mentioned
The size is large to get the quality.

Circuit 1 1287kb Audio/IF circuit diagram

Circuit 2 862kb 8525B Display board circuit diagram

Circuit 3 818kb 8528 Display board circuit diagram - Local head

Circuit 4 703kb 8528 Display board circuit diagram - Remote head

Circuit 5 752kb Microphone Amp circuit diagram

Circuit 6 1021kb Microprocessor controller circuit diagram - Late models

Circuit 7 1140kb Motherboard circuit diagram

Circuit 8 2178kb RF,Mixer & Dual Synthesiser circuit diagram - Late models

Circuit 9 1433kb RF,Mixer & Dual Synthesiser circuit diagram - Early models

Circuit 10 966kb PA & Filter circuit diagram

Circuit 11 536kb Fanswitch circuit diagram

Circuit 12 462kb Datamode switch circuit diagram

Circuit 13 605kb Option AD (antenna driver) circuit diagram

Circuit 14 689kb Two Tone decoder circuit diagram

Circuit 15 1085kb Selcall PCB circuit diagram

Circuit 16 557kb PA/Exciter interface (8528H external 400w PA) circuit diagram