Motorola HT1250-LS+ - Chapter 5 Schematic Diagrams, Overlays, and Parts Lists; Introduction; Notes for All Schematics and Circuit Boards

5-1
Chapter 5
Schematic Diagrams, Overlays, and Parts Lists
5.1 Introduction
This chapter provides schematic diagrams, overlays, and parts lists for the radio circuit boards and
interface connections.
5.1.1 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:
4. Interconnect Tie Point Legend:
CLK = Clock
CSX = Chip Select Line
MECH_SWB+ or SWB+ = Switched Battery Voltage (7.5V)
R5 = Receive Mode 5 V
SYN = Synthesizer
T5 = Transmit Mode 5V
UNSWB+ = Unswitched Battery Voltage (7.5V)
Vdda = Regulated 3.3 Volts (for analog)
Vddd = Regulated 3.3 Volts (for digital)
VSF = Super Filtered (4.5 V)
Circuit Block Series (200 MHz) Series (700 MHz)
Receiver Front End 3300 300
Receiver I-F 3100-3200 350
Frequency Sysnthesizer 3700 200
VCO's 3800 600
Transmitter and Power Control 3500 100
Microprocessor 400 400
Memory 400 400
RX Audio Opamp Gain Stage 600, 2000 850
ASFIC 400 400
Audio Power Amplifier 400 400
Controls and Indicators 500 500
Keypad/PassPort Board Interface 400, 4000 400, 500
Keypoad/PassPort Option Board 600 600