Midland Radio SP-300 service manual

SP-300 Series

SERVICE

MANUAL

Maxon America, Inc. 10828 N.W. Airworld Dr. Kansas City, MO 64153 Tel: 816-891-6320 Fax: 816-891-8815

Part Number: 680-100-0155

April 2001

Contents

Main TABLE OF CONTENTS Page SPECIFICATIONS GENERAL TEMPERATURE RANGE CURRENT CONSUMPTION Page RECEIVER Page SP-300 Series HAND HELD INTRODUCTION FEATURES Main Features Wideband Scan Mode Scan Delay Time Busy Channel Lockout Marked Idle Enable Normal/Inverted DCS Standard/Non-Standard CTCSS SP-300 Series HAND HELD VCO Lock Time Low Battery Indication Memory Protect External Option Detect maxon DESCRIPTION OF CONTROLS THEORY OF OPERATION DIGITAL CIRCUITS z RF CIRCUITS RF CIRCUITS PLL SYNTHESIZER RECEIVER Page MAINTENANCE AND REPAIR GENERAL REMOVING & REPLACING THE BELT CLIP REMOVING & REPLACING THE BATTERY REMOVING & REPLACING PTT ASSY. REMOVING & REPLACING THE ACCES- SORY CONNECTOR REMOVING & REPLACING THE ANTENNA & CONTROL KNOBS REMOVING & REPLACING THE BACK COVER REMOVING & REPLACING THE MAIN BOARD z Page REMOVING & REPLACING THE DAUGH- TER BOARDS z REMOVING & REPLACING THE SPEAKER COMPONENT REPLACEMENT z PROGRAMMING ALIGNMENT PROCEDURE z Page -23- TEST EQUIPMENT SETUP 1. S.S.G. : @ 1kHz Audio: 154.625445681125661 ALIGNMENT POINTS DIAGRAM ALIGNMENT POINTS VHF & UHF WITH TCXO MODULE ALIGNMENT POINTS UHF WITH OUT TCXO MODULE Page -25- TROUBLESHOOTING GUIDE Page -26- VOLTAGE CHARTS z z z CONTROL CIRCUIT RX SP-300 HAND HELD z RECEIVE STATE Page -28- TRANSMIT STATE Page -29- SP-300 SERIES UHF & VHF DIGITAL SECTION PARTS LIST Page -30- Page -31- SP-300 SERIES VHF RF SECTION PARTS LIST Page -32- Page -33- Page -34- SP-300 SERIES UHF RF SECTION PARTS LIST Page -35- Page -36- Page Page -38- COMPONENT PINOUT MMBR951 Q16,17,501,601 KRA104S (PD) Q5,410,412 KRA102S (PB) Q1 D405, 406, 407 Page -39- REFERENCE NO. SCHEMATIC D15 D201,202,301 Page -40- PIN DESCRIPTION 1 12 15 RX/TX VCO SCHEMATICS & BLOCK DIAGRAM ues may differ from schematics shown. VHF FRONT-END Schematic P/N: 770-110-0012 Rev. C PCB Assy. P/N: 650-110-0012 Rev C VHF POWER AMP VCO TX VCO R X 97 10 8 13 - 3 1 47K MMBR9426 PAGE -44- May 2001 Digital Schematic PTT SCHEMATIC P/N:480-042-0028 DESCRIPTIONDESCRIPTIONREV ARELEASED TO MANUFACTURING DGC 5/01 SP-300 Series Digital Schematic Diagram VHF RF Schematic AUDIO AMP DESCRIPTIONDESCRIPTIONREV VCO RX SECTION FUSE SCHEMATIC P/N: 650-200-0004 PAGE -46- May 2001 UHF RF Schematic P.A. MODULE(UHF) SCHEMATIC P/N: 650-230-0013 VCO TX SECTION (UHF) P/N: 650-030-0020 VCO RX SECTION FRONT-END (UHF) SCHEMATIC P/N: 650-110-0013 FUSE SCHEMATIC P/N: 650-200-0004 Block Diagram REVISIONS NA DESCRIPTIONDESCRIPTION RELEASED TO MANUFACTURING REV A PCB LAYOUTS TCXO1 VR3 J3 Board Layout (Top) Main Board Assembly 416121B Exploded View SEE NOTE 3 SEE NOTE 1 SEE NOTE 2