Chapter 2 Uhf Circuit Board Layouts, Schematic Diagrams And Parts List; Notes For All Schematics And Circuit Boards - Motorola HT Series Detailed Service Manual

Chapter 2 UHF Circuit Board Layouts, Schematic
2.1

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
multimeter 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
200 Series
300 Series
400/500 Series =
600 Series
4. Interconnect Tie Point Legend:
UNSWB+
SWB+
R5
CLK
Vdda
Vddd
CSX
SYN
DACRX
VSF
VR
SIX-LAYER CIRCUIT BOARD DETAIL VIEWING
COPPER STEPS IN PROPER LAYER SEQUENCE
Diagrams and Parts List
= Transmitter
= Frequency Generation
= Receiver
Controller
= Keypad board
= Unswitch Battery Voltage (7.5V)
= Switch Battery Voltage (7.5V)
= Receiver 5 Volts
= Clock
= Regulated 3.3 Volts (for analog)
= Regulated 3.3 Volts (for digital)
= Chip Select Line
= Synthesizer
= Digital-to-Analog Voltage (for Receiver Front-End Filter)
= Voltage Super Filtered (5 volts)
= Voltage Regulator
SIDE 1
SIDE 2
LAYER 1 (L1)
LAYER 2 (L2)
LAYER 3 (L3)
INNER LAYERS
LAYER 4 (L4)
LAYER 5 (L5)
LAYER 6 (L6)