Schematic Diagrams, Overlays, And Parts Lists; Introduction; Notes For All Schematics And Circuit Boards - Motorola Professional Radio Service Manual

Chapter 4

Schematic Diagrams, Overlays, and Parts Lists

4.1

Introduction

This chapter provides schematic diagrams, overlays, and parts lists for the radio circuit boards and
interface connections.

4.1.1 Notes For All Schematics and Circuit Boards

* Component is frequency sensitive. Refer to the Electrical Parts List for value and usage.
1. Unless otherwise stated, resistances are in Ohms (k = 1000), and capacitances are in picofarads
(pF) or microfarads (µF).
2. DC voltages are measured from point indicated to chassis ground using a Motorola DC multime-
ter or equivalent. Transmitter measurements should be made with a 1.2 µH choke in series with
the voltage probe to prevent circuit loading.
3. Reference Designators are assigned in the following manner:
100 Series = Transmitter
200 Series = Frequency Generation
300 Series = Receiver
400/500 Series = Controller and Low-Band Receiver Front End
600 Series = Keypad Board
4. Interconnect Tie Point Legend:
UNSWB+ = Unswitched Battery Voltage (7.5V)
SWB+ = Switched Battery Voltage (7.5V)
R5 = Receiver Five Volts
CLK = Clock
Vdda = Regulated 3.3 Volts (for analog)
Vddd = Regulated 3.3 Volts (for digital)
CSX = Chip Select Line (not for LVZIF)
SYN = Synthesizer
DACRX = Digital to Analog Voltage (For Receiver Front End Filter)
VSF = Voltage Super Filtered (5 volts)
VR = Voltage Regulator
4-1