4-1
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), capacitances are in picofarads (pF)
or microfarads
(IJF),
and inductances are in microhenries (!!H) or nanohenries (nH).
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
IJH
choke
in
series with
the voltage probe to prevent circuit loading.
3. Reference Designators are assigned in the following manner:
Radio Main Board
0100
Controller
Microprocessor Section
0200 Audio and ASFIC
0600
Power Supply
0800-0900
Control Head
3000 Receiver Front End
3100 Receiver Back End
3200
Fractionai-N Synthesizer
3300 vco
3400
TX
RF
Power Amplifier
3500
TX
Power Control
PassPort Trunking Controller Board
600 PassPort Trunking Controller
4.
Interconnect Tie Point Legend:
UNSWB+
=
Unswitched Battery Voltage
SWB+
=
Switched Battery Voltage
R5
=
Receiver Five Volts
CLK
=
Clock
Vdda
=
Regulated 5 Volts (for analog)
Vddd
=
Regulated 5 Volts (for digital)
csx
=
Chip Select Line
SYN
=
Synthesizer
VSF
=
Voltage Super Filtered
VR
=
Voltage Regulator
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