Document Outline

• TABLE OF CONTENTS
• SPECIFICATIONS
  • GENERAL
  • TEMPERATURE RANGE
  • CURRENT CONSUMPTION
  • FREQUENCY BANDS
  • DIMENSIONS
  • WEIGHT
  • TRANSMITTER
  • AUDIO FREQUENCY DEVIATION
  • ADJACENT CHANNEL POWER
  • RECEIVER
  • RX TONE DEMODULATION CHARACTERISTICS
• INTRODUCTION
• FEATURES
  • Main Features
  • Wideband
  • Scan Mode
  • Scan Channel Delete
  • Scan Delay Time
  • Busy Channel Lockout
  • Marked Idle Enable
  • Normal/Inverted DCS
  • Standard/Non-Standard CTCSS
  • Transmit Time-Out-Timer (TOT)/TX Inhibit
  • VCO Lock Time
  • Low Battery Indication
  • Memory Protect
  • External Option Detect
• DESCRIPTION OF CONTROLS
• THEORY OF OPERATION
  • DIGITAL CIRCUITS
    • CTCSS/DCS Decode Circuits
    • CTCSS/DCS Encoder Circuit
    • External Mic/PTT Control Circuit
    • Channel Select Circuit
    • Low Battery Indicator Circuit
    • EEPROM
    • High Pass Filter
    • Mute (squelch) Circuit
    • TX Audio And Filter Circuits
    • Analog Ground Supply
    • Audio Mixer And Inverter
    • Monitor
  • RF CIRCUITS
    • Transmitter
    • Buffer
    • P.A. Module
    • Low Pass Filter
    • Antenna Switch
    • Automatic Power Control (APC) Circuits
  • RF CIRCUITS PLL SYNTHESIZER
    • 12.8 MHz TCXO
    • PLL IC Dual Modules Prescaler
    • Level Shifter & Charge Pump
    • Reference Frequency LPF
    • DC to DC Converter
    • VCO
  • RECEIVER
    • Front End
    • First Mixer
    • Second Oscillator Mixer Limiter And FM Detector
    • Squelch (mute) Circuit
    • 16 kHz Band Pass Filter
    • Noise Detector
    • Low Pass Filter
    • Speaker Audio Amplifier
• MAINTENANCE AND REPAIR
  • GENERAL
  • REMOVING & REPLACING THE BELT CLIP
    • Removing the belt clip:
    • To replace the belt clip:
  • REMOVING & REPLACING THE BATTERY
    • To remove the battery:
    • To replace the battery:
  • REMOVING & REPLACING PTT ASSY.
    • To remove the PTT assembly:
    • To replace the PTT assembly:
  • REMOVING & REPLACING THE ACCESSORY CONNECTOR
    • To remove the Accessory Connector:
    • To replace the Accessory Connector:
  • REMOVING & REPLACING THE ANTENNA & CONTROL KNOBS
    • To remove the Antenna:
    • To replace the Antenna:
    • To remove the Control Knobs:
    • To replace the Control Knobs:
  • REMOVING & REPLACING THE BACK COVER
    • To remove the Back Cover:
    • To replace the Back Cover:
  • REMOVING & REPLACING THE MAIN BOARD
    • To remove the Main Board:
    • To replace the Main Board
  • REMOVING & REPLACING THE DAUGHTER BOARDS
    • To Replace a Daughter Board:
  • REMOVING & REPLACING THE SPEAKER
    • To remove the speaker:
    • To replace the speaker
• COMPONENT REPLACEMENT
  • Surface Mount Components
  • Surface Mount Removal
  • Surface Mount Component Replacement
  • Surface Mounted Integrated Circuit Replacement
• PROGRAMMING
  • Cloning
• ALIGNMENT PROCEDURE
  • SQUELCH ADJUSTMENT
  • RX VCO
  • RECEIVER
  • TRANSMITTER
  • TCXO
  • TX VCO
  • CTCSS, DCS & DEVIATION ALIGNMENT
  • APC
• TEST EQUIPMENT SETUP
• ALIGNMENT POINTS DIAGRAM
  • ALIGNMENT POINTS VHF & UHF WITH TCXO MODULE
  • ALIGNMENT POINTS UHF WITH OUT TCXO MODULE
• VOLTAGE CHARTS
• SP-300 SERIES UHF & VHF DIGITAL SECTION PARTS LIST
• SP-300 SERIES VHF RF SECTION PARTS LIST
• SP-300 SERIES UHF RF SECTION PARTS LIST
• COMPONENT PINOUT
• SCHEMATICS & BLOCK DIAGRAM
  • VHF FRONT-END
  • VHF POWER AMP
  • UHF POWER AMP
  • UHF FRONT-END
  • UHF V.C.O.
  • VHF V.C.O.
  • TCXO
  • ACC-200 BATTERY
  • FUSE
  • P.T.T.
  • Digital Schematic
  • VHF RF Schematic
  • UHF RF Schematic
  • Block Diagram
• PCB LAYOUTS
• Exploded View