MOTOROLA GP350 User Guide

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GP350

Portable Radios

146-174 MHz 438-470 MHz

6880904Z07-O

*6880904Z07**6880904Z07*

6880904Z07-O

Motorola

Radius Division

Hwy 34 West

Mt. Pleasant, IA 52641

Computer Software Copyrights

The Motorola products described in this manual may include copyrighted Motorola computer programs stored in semiconductor memories or other

media. Laws in the United States and other countries preserve for Motorola certain exclusive rights for copyrighted computer programs, including

the exclusive right to copy or reproduce in any form, the copyrighted computer program. Accordingly, any copyrighted Motorola computer pro-

grams contained in the Motorola products described in this manual may not be copied or reproduced in any manner without the express written per-

mission of Motorola. Furthermore, the purchase of Motorola products shall not be deemed to grant, either directly or by implication, estoppel or

otherwise, any license under the copyrights, patents or patent applications of Motorola, except for the normal non-exclusive royalty-free license to

use that arises by operation of law in the sale of a product.

Airbag W ar ning Statement

WARNING

VEHICLES EQUIPPED WITH AIR BAGS

An air bag inﬂates with great force. DO NOT place objects, including communication equipment, in the area over the air bag or in the air bag deployment area. If the communication equipment is improperly installed and the air bag inﬂates, this could cause serious injury.

• Installation of vehicle communication equipment should be performed by a professional installer/technician qualiﬁed in the requirements for such installations. An air bag’ s size, shape and deployment area can vary by vehicle make, model and front compartment conﬁguration (e.g., bench seat vs. bucket seats).

• Contact the vehicle manufacturer’s corporate headquarters, if necessary, for speciﬁc air bag information for the vehicle make, model and front compartment conﬁguration involved in your communication equipment installation.

Table of Contents

Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

How to Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Other Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Service Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Ordering Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Model Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Service Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

Test Set Service Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Radio Model Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Radio Service Software Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv

Configuring the RIB and Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv

Section 1 Safety Information

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

FCC Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Section 2 Intrinsically Safe Radio Information

FMRC Approved Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Repair of FMRC Approved Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Relabeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Do Not Substitute Options or Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Section 3 Disassembly/Reassembly

Remove Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Remove Belt Clip from Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Remove Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Remove the Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Re-assembly of Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

6880904Z07-O i

GP350 Portable Radios Service Manual

Section 4 Theory of Operation

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Microcomputer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Microcomputer Power-Up and Reset Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Intermediate Frequency (IF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Frequency Generation Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

VCO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

TX Audio Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Internal MIC Bias Switch and External PTT Sense Circuits . . . . . . . . . . . . . . . . . . 4-4

MIC Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

TX Audio Mute Gate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Pre-emphasis Amplifier (standard models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Option Interface Connector P1 (Keypad/Display models) . . . . . . . . . . . . . . . . . . . 4-4

Limiter (Audio Filter IC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Post-Limiter Filter (Audio Filter IC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

PL Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

DTMF Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Deviation Attenuators (Audio Filter IC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

RX Audio Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

PL Rejection Filter (Audio Filter IC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

PL Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Center-Slicer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Option Interface Connector P1 (Keypad/Display Models) . . . . . . . . . . . . . . . . . . . 4-5

RX Audio Mute Gate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Audio Power Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Noise Squelch Attenuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Vox Circuit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

GP350 Portable Radio Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Receiver, Transmitter, VCO, Synthesizer, and AFIC Block Diagrams . . . . . . . . . . . . . . . . . . . 4-8

Section 5 Troubleshooting

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Troubleshooting Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Troubleshooting Flow Chart for Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Troubleshooting Flow Chart for Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Troubleshooting Flow Chart for Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Troubleshooting Flow Chart for Microprocessor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Troubleshooting Flow Chart for VCO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

ii 6880904Z07-O August, 1996

GP350 Portable Radios Service Manual

Section 6 Component Location Diagrams, Schematic Diagrams, Exploded Views, and Parts Lists

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Schematic Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Parts List: 0180702Y89 Battery Filter Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Parts List: Flex Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Component Location Diagrams, Schematic Diagrams, and Parts Lists for

Battery Filter Board and Flex Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Component Location Diagram for HLD9440A and HLD9441A

VHF, 146-174MHz, Transceiver and Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Schematic Diagram for HLD9440A and HLD9441A

VHF, 146-174MHz, Transceiver Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

Component Location Diagram for HLE9480A and HLE9481A

UHF, 438-470MHz, Transceiver Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Schematic Diagram for HLE9480A and HLE9481A

UHF, 438-470MHz, Transceiver Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

Schematic Diagram for Controller Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Parts List: Controller Components (for all bandsplits) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Parts List: HLD9440A and HLD9441A, 146-174MHz VHF Transceiver. . . . . . . . . . . . . . . . . 6-8

Parts List: HLE9480A and HLE9481A, 438-470MHz UHF Transceiver . . . . . . . . . . . . . . . . . 6-9

Parts List: GP350 Basic Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

HLN9960A DTMF Circuit Board Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

HLN9960A DTMF Schematic Diagram and Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Battery Chargers Single and Multi-Unit Rapid Rate (1 Hour). . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Battery Chargers Single and Multi-Unit Rapid Rate (1 Hour). . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Battery Chargers Standard Rate (10 Hour) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

Battery Chargers Standard Rate (10 Hour) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16

Schematic Diagram and Parts List for HMN9041A Remote Speaker/Microphone . . . . . . . . 6-17

Exploded View and Parts List for HMN9041A Remote Speaker/Microphone . . . . . . . . . . . . 6-18

August, 1996 6880904Z07-O iii

GP350 Portable Radios Service Manual

iv 6880904Z07-O August, 1996

GP350 Portable Radios Service Manual Foreword

Scope of Manual

This manual is intended for use by experienced technicians familiar with similar types of equipment. It contains all service information required for the equipment described and is current as of the printing date. Changes which occur after the printing date are incorporated by instruction manual revision. These revisions are added to the manuals as the engineering changes are incorporated into the equipment.

How to Use This Manual

This manual contains introductory material such as model charts, accessories, and speciﬁcations, as well as four sections that deal with speciﬁc service aspects of the GP350. Refer to the Table of Contents for a general overview of the manual, or to the “Overview” paragraph in each section for a speciﬁc overview of the information in that section.

General

This manual includes speciﬁcations, fundamental disassembly/reassembly procedures, schematic diagrams, component location diagrams, ﬂex circuit diagrams, several parts lists, theory of operation, and troubleshooting sections to cover the GP350 radios. Hereafter, the text will refer collecti vely to the GP350 radios as “this family of radios. ” For operation of the radio, refer to the applicable manual available separately .

Throughout the text in this publication, you will notice the use of warnings, cautions, and notes. These notations are used to emphasize that safety hazards exist, and care must be taken and observed.

WARNING

An operational procedure, practice, or condition, etc., which may result in injury or death if not carefully observed.

CAUTION

An operational procedure, practice, or condition, etc., which may result in damage to the equipment if not carefully observed.

NOTE

An operational procedure, practice, or condition, etc., which is essential to emphasize.

FCC Safety Information

The Federal Communications Commission (FCC), with its action in General Docket 79-144, March 13, 1985, has adopted a safety standard for human exposure to radio frequency (RF) electromagnetic energy emitted by FCC-regulated equipment. Motorola subscribes to the same safety standards for the use of its products. Proper operation of this radio will result in user exposure substantially below the FCC recommended limits.

• Do not hold the radio with the antenna very close to, or touching, exposed parts of the body , especially the f ace, ears, or eyes, while transmitting. Hold the radio in a vertical position with the microphone two to three inches away from the lips.

• Do not hold the transmit switch (PTT) on when not actually desiring to transmit.

• Do not allow children to play with any radio equipment containing a transmitter.

• Do not operate this equipment near electrical blasting caps or in an explosive atmosphere. Under certain conditions, radios can interfere with blasting operations. When you are in the vicinity of construction work, look for, and observe, signs cautioning against radio transmission. If radio transmission is prohibited, you must not transmit until out of the area. Furthermore, you must turn off your radio to prevent any accidental transmission.

• Do not replace or charge batteries in a hazardous atmo-

• Turn radio off when removing or installing a battery.

August, 1996 6880904Z07-O

sphere. Contact sparking may occur while installing or removing batteries and cause an explosion.

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Safety Information GP350 Portable Radios Service Manu FCC Safety Information

This page has been intentionally left blank.

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6880904Z07-O August, 1996

Section 2

Intrinsically Safe Radio Information

FMRC Approved Equipment

Anyone intending to use a radio in a location where hazardous concentrations of ﬂammable material exist (hazardous atmosphere) is advised to become familiar with the subject of intrinsic safety and with the National Electric Code NFP A 70 (National Fire Protection Association) Article 500 (hazardous [classiﬁed] locations).

An Approval Guide, issued by Factory Mutual Research Corporation (FMRC), lists manufacturers and the products approved by FMRC for use in such locations. FMRC has also issued a voluntary approval standard for repair service (“Class Number 3605”)

FMRC Approval labels are attached to the radio to identify the unit as being FM Appro ved for speciﬁed hazardous atmospheres. This label speciﬁes the hazardous Class/Division/ Group along with the part number of the battery that must be used. Their Approval mark is shown below.

APPROVED

WARNING

Do not operate radio communications equipment in a hazardous atmosphere unless it is a type especially qualiﬁed (e.g. FMRC Approved) for such use. An explosion or ﬁre may result.

Do not operate the FMRC Approved Product in a hazardous atmosphere if it has been physically damaged (e.g. cracked housing). An explosion or ﬁre may result.

Do not replace or charge batteries in a hazardous atmosphere. Contact sparking may occur while installing or removing batteries and cause an explosion or ﬁre.

Do not replace or change accessories in a hazardous atmosphere. Contact sparking may occur while installing or removing accessories and cause an explosion or ﬁre.

Do not operate the FMRC Approved Product unit in a hazardous location with the accessory contacts exposed. Keep the connector cover in place when accessories are not used.

Turn radio of f before removing or installing a battery or accessory.

Do not disassemble the FMRC Approved Product unit in any way that exposes the internal electrical circuits of the unit.

Radios must ship from the Motorola manufacturing facility with the hazardous atmosphere capability and FM Appro v al labeling. Radios will not be “upgraded” to this capability and labeled in the ﬁeld.

A modiﬁcation changes the unit’s hardware from its original design conﬁguration. Modiﬁcations can only be done by the original product manufacturer at one of its FMRC audited manufacturing facilities.

WARNING

Failure to use an FMRC Approved Product unit with an FMRC Approved battery or FMRC Approved accessories speciﬁcally approved for that product may result in the dangerously unsafe condition of an unapproved radio combination being used in a hazardous location.

Unauthorized or incorrect modiﬁcation of an FMRC Appro ved Product unit will negate the Approval rating of the product.

Repair of FMRC Approved Products

REPAIRS FOR MOTOROLA FMRC APPROVED PRODUCTS ARE THE RESPONSIBILITY OF THE USER.

Y ou may want to consider using a repair facility that operates under 3605 repair service approval.

WARNING

Incorrect repair or relabeling of any FMRC Approved Product unit could adversely affect the Approval rating of the unit.

Use of a radio that is not intrinsically safe in a hazardous atmosphere could result in serious injury or death.

FMRC’s Approv al Standard Class Number 3605 is subject to change at any time without notice to you, so you may want to obtain a current copy of 3605 from FMRC. Per the December, 1994 publication of 3605, some key deﬁnitions and service requirements are as follows:

August, 1996 6880904Z07-O

2-1

nual

Intrinsically Safe Radio Information GP350 Portable Radios Service Ma Repair of FMRC Approved Products

Repair

A repair constitutes something done internally to the unit that would bring it back to its original condition Appro ved by FMRC. A repair should be done in an FMRC Appro ved facility.

Items not considered as repairs are those in which an action is performed on a unit which does not require the outer casing of the unit to be opened in a manner which exposes the internal electrical circuits of the unit. You do not have to be an FMRC Appro ved Repair Facility to perform these actions.

Relabeling

The repair facility shall have a method by which the replacement of FMRC Appro v al labels are controlled to ensure that any relabeling is limited to units that were originally shipped from the Manufacturer with an FM Approval label in place. FMRC Approval labels shall not be stocked by the repair facility . An FMRC Appro val label shall be ordered from the original manufacturer as needed to repair a speciﬁc unit. Replacement labels may be obtained and applied by the repair facility providing satisfactory evidence that the unit being relabeled was originally an FMRC Appro ved unit. Veriﬁcation may include, but is not limited to: a unit with a damaged Approval label, a unit with a defective housing displaying an Approval label, or a customer invoice indicating the serial number of the unit and purchase of an FMRC Approved model.

Do Not Substitute Options or Accessories

The communications equipment package that Motorola submits to FMRC for testing and approval is tested as a system that consists of the communications unit itself and the battery, antenna and other options or accessories that make up the rest of the package to be approved. This approved package must be strictly observed and there must be no substitution of items, even if the substitute you wanted to consider appears as an approved accessory elsewhere in the Guide for some other communications equipment unit. Approved conﬁgurations are listed by FMRC Approved Product in the annual Appro val Guide published by FMRC. That guide, and the Appro val Standard Class Number 3605 document, can be ordered from the following address.

Training Resource Center Publications-Order Processing Dept. Factory Mutual Engineering and Research 1151 Boston-Providence Turnpike PO Box 9102 Norwood, MA, 02062 telephone (617) 762-4300

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6880904Z07-O August, 1996

MAEPF-25235-O

Figure 3-3.

Chassis to Front Cover

Snaps are Located Here

Figure 3-4.

Section 3

Disassembly/Reassembly

Remove Battery

1. Locate the battery latch on the bottom of the radio. Push the battery latch toward the front of the radio and hold it in the open position as shown in Figure 3-1.

Figure 3-1.

2. While holding the battery latch in the open position, slide the battery down approximately 1/2 inch and then off the radio housing as shown in Figure 3-2.

Figure 3-2.

MAEPF-25233-O

MAEPF-25234-O

3. Using a ﬂat-blade screwdriver, carefully pry chassis up on both sides of slot at bottom center of radio (Figure 3-4).

Remove Belt Clip from Battery

1. Push in on tab of belt clip with small ﬂat

Remove Chassis

1. Pull both control knobs straight off to remove.

2. Unscrew antenna counterclockwise to remove.

August, 1996 6880904Z07-O

bladed

screwdriver, and at the same time slide belt clip toward top of radio (Figure 3-3).

CAUTION

Lift the chassis approximately of the front cover, because you must disconnect the ﬂex cable before completely removing the chassis.

4. Disconnect the ﬂex cable connector using a ﬂat blade screwdriver, as shown in Figure 3-5.

half way out

3-1

Disassembly/Reassembly GP350 Portable Radio Service Manual Remove the Main Board

5. Pull the chassis out and away from the housing as shown by the arrow in Figure 3-5.

3. After all four chassis clips have been removed, separate the main board from the chassis as shown in the exploded view Figure 3-7.

Flex Cable

Figure 3-5.

MAEPF-25237-O

Remove the Main Board

1. The main board is sandwiched between the front shield and the chassis. Four chassis clips hold the sandwiched assembly together. Remo ve the chassis gasket and place the radio shield side down on a ﬂat surface.

2. Using a small ﬂat blade screwdriver, unlock the four chassis clips while pressing down on the chassis directly above each clip. (Refer to Figure 3-6.)

Chassis Clips

Figure 1-7.

Figure 3-7.

Re-assembly of Radio

Reverse the disassembly

IMPORTANT

Be sure to reinstall the chassis gasket. This gasket helps keep the main board free of unwanted dirt, dust, and water.

procedure.

MAEPF-25239-O

3-2

Figure 3-6.

6880904Z07-O August, 1996

Section 4

Theory of Operation

Overview

This section provides a detailed theory of operation for the GP350 and its components: the microcomputer, the receiver, the transmitter, and the frequency generation circuitry.

Microcomputer

The GP350 VHF and UHF radios use the Motorola 68HC11A8 microcomputer, U401, which utilizes:

• 7.9488 MHz clock rate

• Multiplexed 8-bit address/data lines

• 16-bit addressing

• Internal watchdog circuitry

• Analog to digital conversion input ports

The microcomputer’s operating program is permanently written or “masked” within the microcomputer. Included in U401 is an EEPROM memory which stores channel, signalling, and scan list information.

Microcomputer Power-Up and Reset Routine

Receiver

The receiver of the GP350 UHF and VHF radios consists of 4 major blocks each: the front-end module, the double balanced mixer, the 45.1 MHz IF and the back-end IF IC.

The UHF and VHF front-end modules consist of three blocks of circuitry each: A pre-selector, RF ampliﬁer and a post- selector ﬁlter. These three items are located on a receiver module pc-board that stands perpendicular to the main radio pc-board. This module is enclosed in a shield to prevent radiation into and out of the module. All ﬁlters on the UHF and VHF modules are ﬁxed tuned designs to eliminate the need for factory tuning and to provide wide-band operation.

The shunt and series coupled resonator topology yields a more symmetrical frequency response to guard against strong out of band signals that could produce IM products.

The worst case image frequency in the VHF band is

90.2 MHz above the ﬁlter passband. The 3 db bandwidth is approximately 35 MHz, centered at 160 MHz. The center of the band insertion loss is approximately 1.9 db. The 4-pole ﬁlter is designed to operate with a 50 ohm input termination, while the output termination is the input impedance of the RF ampliﬁer that follows it.

On power-up U401’s reset line (pin 43) is held low by the AFIC (U402) until the synthesizer (U201) provides a stable

2.1 MHz output. When U402 releases its control, U401’s hardware holds the reset line low until it veriﬁes that clock Y401 is operational. When the reset line goes “high,” U401’s hardware delays brieﬂy to allow Y401 to stabilize, then the software begins executing port assignments, RAM checking, and initialization. A ﬁxed delay of 100 ms is added to allow the audio circuitry to settle. Next, an alert beep is generated and the steady state software begins to execute (buttons are read, radio circuits are controlled).

U401’s reset line can be controlled directly by the 5V regulator (U411), the AFIC, and the microcomputer, and indirectly by the synthesizer. U411 drives the reset line low (via pin 3) if it loses regulation. This prevents possible latch-up or overwriting of registers in the microcomputer because the reset line is higher in voltage than pin 55 of U401 (VDD).

U401 can drive the reset line low if it detects a fault condition such as an expired watchdog timer, software stuck in an inﬁnite loop, unplanned hardware inputs, static zaps, etc.

The AFIC and synthesizer can control the reset line during power-up, as outlined above.

The UHF pre-selector ﬁlter is a 3-pole,.01 db Chebyshev bandpass design implemented in a shunt coupled resonator topology. This topology maximizes the attenuation at the worst case image frequency for this receiver, which is 90.2 MHz below the ﬁlter passband. The 3 db bandwidth is approximately 45 MHz, centered at 454 MHz. The center of the band insertion loss is approximately 2.2 db. The 3-pole ﬁlter is designed to operate with a 50 ohm input termination, while the output termination is the input impedance of the RF ampliﬁer that follows it.

The RF ampliﬁer, Q1, is a Motorola MMBR571 NPN device biased in a common emitter conﬁguration. The ampliﬁer is stabilized by the shunt feedback resistor R3, and has approximately 16.5 db of gain with a noise ﬁgure of about 3.0 db (VHF) and 2.2 db (UHF). The ampliﬁer draws 4 ma of current and is supplied by the receiver 5 volt supply (indicated as “+5R” on the schematics and block diagrams).

Terminating the RF ampliﬁer is the post-selector ﬁlter. This ﬁlter is a 3-pole for VHF and a 4-pole for UHF,.01 db Chebyshev design which is also implemented in a series coupled resonator topology for maximum image attenuation. The 3 db bandwidth is approximately 38 MHz centered at 160 MHz for VHF and 42.5 MHz centered at 454 MHz for UHF.

August, 1996 6880904Z07-O 4-1

Theory of Operation GP350 Portable Radios Service Manual Transmitter

The insertion loss of this ﬁlter is approximately 1.9 db for VHF and 3.5 db for UHF. The ﬁlter is designed to be terminated with the ampliﬁer output impedance on one side, and 50 ohm on the other.

The net gain from the receiver module is about (12.2 db VHF) (10.8 db UHF) in the center of the band and about (10.7 db VHF) (9.5 db UHF) at the band edges. The net center of the band noise ﬁgure is approximately (5.5 db VHF) (5.2 db UHF). This is sufﬁcient to achieve a typical center of the band sensitivity of 12 dbs.

The double balanced mixer is composed of the two baluns, T1 and T2, and the ring diode IC, CR2. The mixer operates with a local oscillator (LO) level of +6 dbm and the conversion loss is approximately 7.5 db. The double balanced type mixer (DBM) provides excellent isolation between any two ports. And since a DBM can operate over a large bandwidth, the same mixer can be used for UHF and VHF radios. The DBM also provides excellent protection against receiver spurs due to non-linearizes, such as IM and Half-IF. The received signal mixes down to the frequency of the ﬁrst IF,

45.1 MHz, and enters the IF circuitry.

Intermediate Frequency (IF)

The Intermediate Frequency (IF) section of the portable radio consists of several sections including, the “high” IF, the second LO, the second IF, and the IF IC chip. The ﬁrst LO signal and the RF signal mix to the IF frequency of 45.1 Mhz, and then enters the IF portion of the radio.

The signal ﬁrst enters the “high” IF, passes through a crystal ﬁlter, is then ampliﬁed by the IF ampliﬁer, and then passed through another crystal ﬁlter. The ﬁrst crystal ﬁlter provides selectivity, second image protection, and intermodulation protection. The ampliﬁer provides approximately 16 dB of gain to the signal. The signal then passes through the second crystal ﬁlter which provides further selectivity and second image protection. The “high” IF has an approximate 3 dB bandwidth of 7 KHz for 20/25/30 KHz models and 4 KHz for 12.5 KHz models.

The ﬁltered and ampliﬁed IF signal then mixes with the second local oscillator at 44.645 MHz. The second LO uses an ampliﬁer internal to the IF IC, an external crystal and some external chip parts. The oscillator presents an approximate level of -15 dBm to the second IF mixer, internal to the IF IC.

The output of the mixing of the IF signal and the second LO produces a signal at 455 KHz (second IF). This signal is then ﬁltered by external ceramic ﬁlters and ampliﬁed. It is then passed back to the IF IC, sent to a phase-lock detector, and demodulated. The resulting detected audio output is then sent to the AFIC to recover the audio.

The IF IC also controls the squelch characteristics of the radio. With a few external parts the squelch tail, hysteresis, attack and delay times were optimized for the radio. The AFIC allows the radio’s squelch opening to be electronically adjusted.

Transmitter

The GP350 VHF and UHF transmitters contain ﬁve basic circuits: a power ampliﬁer, an antenna switch, a harmonic ﬁlter, an antenna matching network, and a power control Refer to the block diagram and the schematic for more information.

The power ampliﬁer for VHF contains three stages of ampliﬁcation. For UHF, the power module contains four stages. Both modules require an input signal of 1 mW, a supply voltage of 7.5 volts, and are capable of supplying, at least, 7 Watts of output. The power out of both modules can be varied by changing the voltage on their second stage.

The antenna switch circuit consists of two PIN diodes (CR101 and CR102), a pi network (C119, L112, and part of C112), and at least, one current limiting resistor (R102 for UHF; and R102, R103, and R108 for VHF). In the transmit mode, TX B+ is applied to the circuit to bias the diodes “on”. The shunt diode (CR102) shorts out the receiver port, and the pi network, which operates as a quarter wave transmission line, transforms the low impedance of the shunt diode to a “high” impedance at the input of the harmonic ﬁlter. In the receive mode, the diodes are both off, and hence, there exists a low attenuation path between the antenna and receiver ports.

The harmonic ﬁlter consists of part of C112, and L107, C113, L108, C114, L109, and C115. The design of the harmonic ﬁlter for both VHF and UHF is that of a Zolotarev design. This particular design is similar to that of a Chebyshev ﬁlter except for a large amplitude ﬁrst ripple (near dc). This type of ﬁlter has the advantage that it can give greater attenuation in the stop-band for a given ripple level.

Another feature of this type of ﬁlter is that the coils tend to be smaller than with a Chebyshev design. The design of the VHF ﬁlter was modiﬁed from the Zolotarev design by slightly changing its capacitor values to yield a ﬁlter having an input impedance which optimized the efﬁciency of the power module.

To optimize the performance of the transmitter and receiver into an antenna, a network is used to match the antenna’s impedance to the harmonic ﬁlter. For VHF the network consists of C117, L111, and C122. For UHF the network is made up of C117 and L111. Note that, in order to measure the power out of the transmitter, one must remove the antenna and screw in its place a special BNC-to-Phono adapter.

The power control circuit consists of the networks associated with U151, Q156, Q151, Q152, Q155, and U152. The Op Amp U151A and Q156, along with resistor R101, make up a current-to-voltage ampliﬁer whose gain is mainly dependent upon the ratio of R179 to R153. The current to the ﬁnal stage of the power module is supplied through R101 (0.1 Ohms), which provides a voltage proportional to the current drain. This voltage is ampliﬁed and applied to the input of U151B. The resistors at the input of U151A (R151, R152, R154, and R155) keep the voltages at the inputs of U151A below its maximum allowable. These resistors are 1% tolerance parts

4-2 6880904Z07-O August, 1996

GP350 Portable Radios Service Manual Theory of Operation Frequency Generation Circuitry

to minimize the error produced at the emitter of Q156 resulting from the voltage offset at the input of U151A.

The voltage at the other input of the summing ampliﬁer, U151B, is supplied from two DACs contained within U152. These DACs are controlled by the microprocessor, and provide the reference voltage for the control loop. One of the DACs, that connected to Pin 9 of U152, provides a coarse tune voltage, while the other provides a ﬁne tune voltage. Since the output of the DACs is not zero when they are set to their lowest level, resistor R169 is provided to bias up the minus input of the summing ampliﬁer to compensate for the bias resulting from the DACs.

The error voltage at the input of U151B produces a voltage at its output, which is in turn applied to the series pass transistor, Q152, through its driver, Q151. The voltage at the collector of Q152 is applied to the controlled stage of the power module, which for both VHF and UHF is the module’s second stage. The feedback from the collector of Q152 to the emitter of Q151 through R166 is provided to keep the two stages stable. Likewise, the feedback from the collector of Q152 to the minus input of the summing ampliﬁer is to keep the whole control loop stable.

The purpose of Q155 and its associated circuitry is to keep the control voltage on the module below 7.0 volts, which is the maximum allowed for the UHF module.

The purpose of R173 was originally that of providing compensation to the control loop for changes in the supply voltage, TX B+. However, experimentation has shown that this compensation is not really required. Also, thermistor, R170, was provided to enable the shut back of the PA in the event that it would get too hot. This has also been shown to not be required

Frequency Generation Circuitry

The frequency generation circuitry is composed of two main IC’s, the Fractional-N synthesizer (U201) and the VCO/ Buffer IC (U251). Designed in conjunction to maximize compatibility, the two IC’s provide many of the functions which normally would require additional circuitry. The block diagram illustrates the interconnect and support circuitry used in the design. Refer to the schematic for reference designator.

The supply for the synthesizer is from Regulated 5 volts which also serves the rest of the radio. The synthesizer in turn generates a superﬁltered 5 volts (*actually 4.65 volts) which powers U251.

nally the audio is digitized by the Fractional-N and applied to the loop divider to provide the low-port modulation. The audio is also run through an internal attenuator for modulation balancing purposes before being outputted at pin 28 to the VCO. A 2.1 MHz clock for the AFIC is generated by the Fractional-N and is routed to pin 11 where it is ﬁltered and attenuated from 2.5 volts to approximately 2 volts.

Synthesizer

The Fractional-N synthesizer uses a 16.8 MHz crystal (Y201) to provide the reference frequency for the system. The other reference oscillator components external to the IC are C205, C206, R207, and CR203. The 16.8 MHz signal is divided down signal from the VCO. The loop ﬁlter, comprised of R201, R202, R205, C201, C214, C215, and C216, provides the necessary dc steering voltage for the VCO as well as ﬁltering of spurious signals from the phase detector. For achieving fast locking of the synthesizer, an internal adapt charge pump provides higher current capability at pin 31 than when in the normal steady-state mode. Both the normal and adapt charge pumps receive their supply from the voltage multiplier which is made up of C202, C203, C204, C231, CR201, and CR202. By combining two 5 volt square waves which are 180 out-of-phase along with Regulated 5 volts, a supply of approximately 12.6 volts is available at pin 32 for the charge pumps. The current for the normal mode charge pumps is set by R203. The pre-scaler for the loop is internal to U201 with the value determined by the frequency band of operation.

VCO

The VCO (U251) in conjunction with the Fractional-N synthesizer (U201) generates rf in both the receive and the transmit modes of operation. The TRB line (U251 pin 5) determines which oscillator and buffer will be enabled. A sample of the rf signal from the enabled oscillator is routed from U251 pin 23, through a low pass ﬁlter, to the pre-scaler input (U201 pin 20). After frequency comparison in the synthesizer, a resultant CONTROL VOLTAGE is received at the VCO. This voltage is a DC voltage between 3 and 10 volts when the PLL is locked on frequency.

In the receive mode, U251 pin 5 is grounded. This activates the receive VCO by enabling the receive oscillator and the receive buffer of U251. The rf signal at U251 pin 2 is run through a low pass ﬁlter. The rf signal after the low pass ﬁlter is the LO RF INJECTION and it is applied to the ﬁrst mixer at T2.

In addition to the VCO, the synthesizer must interface with the logic and AFIC circuitry. Programming for the synthesizer is accomplished through the data, clock, and chip enable lines (pins 5, 6, and 7) from the microprocessor, U401. A serial stream of 98 bits is sent whenever the synthesizer is programmed. A 5 volt dc signal from pin 2 indicates to the microprocessor that the synthesizer is locked while unlock is indicated by a low voltage on this pin. Transmit modulation from the AFIC is applied to pin 8 of U201. Inter-

August, 1996 6880904Z07-O 4-3

During the transmit condition, PTT depressed, ﬁve volts is applied to U251 pin 5. This activates the transmit VCO by enabling the transmit oscillator and the transmit buffer of U251. The rf signal at U251 pin 4 is run through a low pass ﬁlter and an attenuator to give the correct drive level to the input of the PA module (U101 pin 1). This rf signal is the TX RF INJECTION. Also in transmit mode, the audio signal to be frequency modulated onto the carrier is received by the transmit VCO modulation circuitry at AUDIO IN.

Theory of Operation GP350 Portable Radios Service Manual Frequency Generation Circuitry

When a “high” impedance is applied to U251 pin 5, the VCO is operating in BATTERY SAVER mode. In this case, both the receive and transmit oscillators as well as the receive, transmit, and pre-scaler buffer are turned off. In the Fractional-N, the battery saver mode places the A/D and the modulation attenuator in the off state. This mode is used to reduce current drain on the radio.

GP350 receive (RX) and transmit (TX) circuits are common to both the VHF and UHF models. Most of the radio processing for RX and TX is accomplished in U402, the Audio Filter IC. The Audio Filter IC performs the following functions:

• Tone/Digital PL encoding and decoding

• PL rejection ﬁlter (RX audio)

• TX pre-emphasis ampliﬁer

• Limiter

• Post-limiter ﬁlter

• TX deviation digital attenuators

• MIC gain attenuator

• Noise squelch digital attenuator

• Microcontroller port expanders (output only)

• 2.5 Vdc reference source

U402 parameters are programmed from U401 microcontroller ROM and EEPROM data via the serial CLOCK and DATA lines. Unless otherwise indicated, all signal levels refer to standard carrier modulation, 1kHz tone at +/-3kHz deviation.

TX Audio Path

detect line on U401-19, or to the internal PTT (U409-42), to transmit the headset audio.

MIC Ampliﬁer

There are two MIC ampliﬁers inside U409. The MIC-enable line, U409-18, is always biased “on” for VOX applications. The ampliﬁers are selected according to the bias on U40920, which is the collector voltage on Q408. The external audio ampliﬁer, U409-21, is active when U409-20 is “high” (5 volts), and the internal audio ampliﬁer, U409-22, is active when U409-20 is low (0 volts). The audio signal then exits U409-19 and proceeds through a low pass network (C516, C517, and R516) into U409-12 and out through U409-11, with R515 providing feedback. This circuit supplies a low frequency “roll off” for improved audio clarity. Capacitor C519 and resistor R518 provide the output bias for the MIC ampliﬁers.

TX Audio Mute Gate

PNP transistor Q409, and resistors R462 and R463 comprise the TX audio mute gate. The audio Filter IC expanded output port (U402-40), controls Q409 as well as the internal MIC bias switch (Q407). When U402-40 is logic LO state, a small dc current ﬂows from U409-11 MIC ampliﬁer output into Q409 emitter, through Q409, and out of the collector through R462. A fraction of the emitter current ﬂows out of the base through R463 to ground (Vss of Audio Filter IC). MIC audio at U409-11 passes through the TX audio mute gate. When U402-40 is logic “high,” Q409 base voltage is 4Vdc (typical) and emitter voltage is 2.4 Vdc, biasing the device well into cut-off. No current ﬂows through emitter to base/collector, and no MIC audio passes. The mute function is enabled (Q409 is “OFF”) when modulating DTMF or 5/6 tone (European) Signalling.

Internal MIC Bias Switch and External PTT Sense Circuits

PNP switch transistor Q407, resistors R453, R454, and capacitor C463 control the operating bias for internal MIC MK401. Q407 is controlled by microcontroller U401 via U402-40, the Audio Filter IC expanded output port. On connecting an external MIC through the side connector adapter, the external PTT sense transistor (Q408) switches “on” when the external PTT is closed. In PTT-equipped accessories, the PTT switch is series-connected with the MIC element. When this PTT is closed, 5-volts “high” is produced on the collector of Q408 and monitored by U401-14. When the collector voltage is “high” (5 volts), the microcontroller conﬁgures the radio for transmit mode.

There is no series-wired PTT within the headsets. These accessories always keep the collector of Q408 “high.” With headsets, the radio must be programmed for headsets or Audio Sense. When programmed for Audio Sense, on power-up the microcontroller (U401) reads that line 14 is “high” and interprets that there is a headset attached. When the radio is programmed for headsets, the microprocessor ignores line 14 for PTT operation and it “looks” to the VOX

4-4 6880904Z07-O August, 1996

Pre-emphasis Ampliﬁer (standard models)

U402, the Audio Filter IC, contains a TX audio pre-emphasis ampliﬁer, with external gain setting resistor R504, and preemphasis elements R506 and C462. Connections are made at each end of resistor R506 to provide interconnection of “front cover” option board TX audio through connector P1 (below). Pre-emphasis is 6 dB/octave.

Option Interface Connector P1 (Keypad/Display models)

P1 provides interconnection of “front cover” option PC boards to the GP350 radio main board. MIC audio output is available from P1-5 at a level of 45 mVrms and 10k ohm output impedance. Option TX Audio input to the GP350 radio is available at P1-4 with sensitivity of 40 mV rms, pre-emphasized at 6 dB/octave, and less than 200 ohm output impedance (from option board). If “ﬂat” audio response is required, the audio output from the option board must be deemphasized at a -6 dB/octave rate, 300Hz to 3kHz, with 0 dB gain at 1kHz. The low option board output impedance is required to achieve better than 40 dB isolation between main board input (P1-4) and output (P1-5) audio.

GP350 Portable Radios Service Manual Theory of Operation Frequency Generation Circuitry

Limiter (Audio Filter IC)

The audio ﬁlter IC U402 contains the limiter circuit, which prevents over-deviation of the RF carrier by symmetrically clipping the peaks of the modulating voltage. Audio from the pre-emphasis ampliﬁer circuit is coupled to the limiter. Gain of the limiter stage is adjustable in four 3 dB steps, from -3 dB to +6 dB. Therefore, TX audio path gain, or MIC gain, can be adjusted to compensate for different sound environments through the Radio Service Software.

Post-Limiter Filter (Audio Filter IC)

Clipped modulating voltage from the limiter output is coupled to the post-limiter ﬁlter. Filtering attenuates the spurious products generated by the limiter. The post-limiter ﬁlter is programmable to operate in the following modes:

• CEPT/EIA mode

• Japan mode

• FTZ (Germany) mode

PL Encoder

Private Line (CTCSS) is generated by the PL encoder circuit in U402, the Audio Filter IC. Tone PL or Digital PL data is programmed for each mode from the Radio Service Software. On entering transmit mode, TPL or DPL data is programmed to U402 via the serial DATA and CLOCK lines. U401-35 microcontroller output strobes &402-32 PL clock input at a constant rate during DPL encoding, or at a rate determined by the PL encoder algorithm in the microcontroller for TPL encoding corresponding to tone frequency. The encoded PL is summed with MIC audio at the post-limiter ﬁlter input. Digital attenuators are employed to adjust the balance of MIC radio and PL to prevent over-deviation of the carrier. PL deviation is adjustable in three “coarse” steps of 500 Hz, 750 Hz, and 1 kHz, for 25 KHz models and steps of 250 Hz, 375 Hz, and 500 Hz for 12.5KHz models with compensation of MIC audio level.

DTMF Encoder

Resistors R424, R425, R426, R428 and R484, and summer U405A form the DTMF encoder. U405A-1 is coupled to U402-13 Audio Filter IC auxiliary TX modulation input.

DTMF encoded signals pass from this input to the post-limiter ﬁlter input. U405A-1 is also coupled to U402-12 and coupled through RX audio path to the audio PA for sidetone audio.

Deviation Attenuators (Audio Filter IC)

R479 and dc-coupled to U201-8, the synthesizer modulation input. Capacitor C218 provides a “high” frequency roll-off corner at 20 kHz to further attenuate spurious signals from U402. The dc voltage at the combined attenuator outputs sets the center frequency for the modulated carrier. Any transient (R x C) voltages in the TX audio path must settle within 1 millisecond of PTT activation to prevent center frequency offset.

RX Audio Path

PL Rejection Filter (Audio Filter IC)

The recovered RX audio from the IF detector IC U51 is coupled through capacitor C435 to U402-7 and U402-8 on the Audio Filter IC. RX audio at U402-7 is processed ﬁrst by the PL rejection ﬁlter, which is characterized by a two pole, 300 Hz corner frequency “high-pass” response. Audio then passes through the digital volume attenuator and buffer ampliﬁer output to U402-23. Unattenuated RX audio is coupled to U402-22 and fed to the center-slicer circuit for detection of 5/6 tone (European) signals. For standard test modulation, the audio level at U402-7 is 255 mVrms, and output audio level at U402-23 is 765 mVrms with the digital volume attenuator set to minimum attenuation.

PL Decoder

Recovered RX audio at U402-8, the PL decoder input, ﬁrst passes through the Tone PL ﬁlter, or the Digital PL ﬁlter, depending on the PL option selected for the current operating mode. Filtered PL is then coupled to the PL detector circuit, with detected PL output at U402-27. The detected PL signal is coupled from U402-27 to microcontroller U401-64 where algorithms perform the ﬁnal PL decoding. Data for the Tone PL frequency or Digital PL code for each mode is programmed through the Radio Service Software.

Center-Slicer

The center-slicer circuit U406A detects Quick-Call and 5/6 tone signals. Unattenuated RX audio from U402-22 is dc coupled to the two inputs of U406A. The non-inverting input U406A-3 is fed through resistor R433. Capacitor C415 sets a low-pass corner frequency of 3.3 kHz. The inverting input U406A-2 is fed through resistor R434. Capacitor C416 sets a low-pass corner frequency of 16 Hz. During operation, R434 / C416 establish an averaged dc offset level at U406A2 dependent on the average dc level of the undetected signal to set the “trigger” threshold of U406A. R433 / C415 provide “high” audio frequency roll-off to improve falsing immunity. The detected output from the center slicer circuit is coupled to microcontroller U401-43 where algorithms perform the ﬁnal data decoding.

Carrier deviation is set by programming the digital deviation attenuators of the Audio Filter IC. Deviation data for each mode is entered through the Radio Service Software, and then programmed into U402 from microcontroller U401 on entering transmit mode. U402-19 and U402-20 deviation attenuator outputs are combined through resistors R478 and

August, 1996 6880904Z07-O 4-5

Option Interface Connector P1 (Keypad/Display Models)

P1 provides interconnection of “front cover” option pc boards to the GP350 radio main board. Filtered “ﬂat” RX audio output is available at P1-7, at a level of 765 mVrms at

Theory of Operation GP350 Portable Radios Service Manual Frequency Generation Circuitry

15k-ohm impedance. P1-7 is always unmuted, not affected by the receiver with squelch circuit. Option RX audio input to the GP350 radio is available at P1-6, with a sensitivity of 100 mVrms at less than 200 ohm output impedance from option board.

RX Audio Mute Gate

PNP transistor Q406, the RX audio mute gate, with resistors R458 and R459, and capacitors C432 and C433, provide receiver audio muting. The RX audio mute gate circuit functions in a similar manner to Q409, the TX audio mute gate circuit. Muting is controlled by microcontroller U401 via U402-39, an Audio Filter IC expanded output port. Q406 is saturated and RX audio unmuted by programming U402-39 to a logic “LO” state. Q406 is placed well into cut-off and RX audio muted by programming U402-39 to a logic “high” state.

Audio Power Ampliﬁer

Variable resistor R460 and resistor R461 provide RX audio volume adjustment. R461 sets the minimum volume level. R466 and R464 form a resistor divider to set the audio input amplitude into the ampliﬁer (U409-10), which is ac-coupled by C518. Fixed level Alert Tone audio is generated by microcontroller U401-56 and coupled through capacitor C437 and resistor R465 into the audio path. The audio ampliﬁer (U409) has three ampliﬁers designed to differentially drive its load. Two of the three ampliﬁers simultaneously drive the 16- ohm speaker. All the ampliﬁers are enabled with “high” (5 volts) on U409-23, which is activated by the AFIC (U402-

3). The common ampliﬁer (U409-31 and U409-32) is always on, and either the external ampliﬁer (U409-4 and U409-5) or the internal ampliﬁer (U409-27 and U409-28) is on, depending on the bias of the logic circuits (U409-24). If U409-24 is “high,” the internal ampliﬁer (U409-27 and U409-28) is on; if U409-24 is low, the external ampliﬁer (U409-4 and U409-

5) is on. This is how the audio is switched between the internal speaker and the accessories.

triggering by “high” frequency ambient noise. Resistors R442, R443, R444, R445, and R491, capacitor C423, rectiﬁer diode CR404 and U406B form a linear peak detector circuit. MIC audio causes capacitor C423 to charge to a potential related to the relative amplitude of ambient noise. Microcontroller U401-19 monitors the potential of C423 and establishes a threshold for non-voiced ambient noise. When a positive rise in potential above threshold or voice is detected by an algorithm in the microcontroller ROM, the radio is conﬁgured to transmit mode.

Noise Squelch Attenuator

The Audio Filter IC U402 contains a 16 step programmable digital squelch attenuator between U402-16 and U402-18. Noise squelch is set using the Radio Service Software, with open squelch at step 0, and tight squelch at step 15.

Vox Circuit Operation

As mentioned above, with VOX option enabled, a VOX (non-PTT) accessory can be plugged into the adaptor for voice-activated transmit operation. The external MIC element is always supplied with operating bias through resistor R451 and external PTT sense transistor Q408. The external PTT sense at microcontroller U401-14 is therefore, always “enabled.” A second output circuit of MIC ampliﬁer U40911 couples MIC audio through capacitor C445 to U406B, the VOX detector circuit. Resistors R492 and R493, and capacitor C451 form a syllabic ﬁlter which reduces VOX circuit

4-6 6880904Z07-O August, 1996

INSERT PAGE SIZE AND RADIO BLOCK DIAGRAM FROM MANUAL 6880902Z30-D, PAGE 2-7

GP350 Portable Radio

Functional Block Diagram

August, 1996 6880904Z07-O 4-7

INSERT PAGE SIZE, RECEIVER BLOCK DIAGRAM, TRANSMITTER BLOCK DIAGRAM, VCO BLOCK DIAGRAM, SYNTHESIZER BLOCK DIIAGRAM, AND AFIC BLOCK DIAGRAM FOR MANUAL 6880902Z30-D, PAGE 2-8

Receiver, Transmitter, VCO, Synthesizer, and AFIC Block Diagrams

4-8 6880904Z07-O August, 1996

Overview

This section contains three troubleshooting tables for the following GP350 components:

• Receiver

• Transmitter

• Synthesizer

• Microprocessor

• Voltage Controlled Oscillator (VCO)

Troubleshooting Charts

Refer to following pages.

Section 5

Troubleshooting

August, 1996 6880904Z07-O 5-1

INSERT LINE ART FROM MANUAL 6880902Z30-D, PAGE 4-3

Troubleshooting Flow Chart for Receiver

5-2 6880904Z07-O August, 1996

INSERT LINE ART FROM MANUAL 6880902Z30-D, PAGE 4-4

Troubleshooting Flow Chart

for Transmitter

August, 1996 6880904Z07-O 5-3

INSERT LINE ART FROM MANUAL 6880902Z30-D, PAGE 4-5

Troubleshooting Flow Chart for Synthesizer

5-4 6880904Z07-O August, 1996

INSERT LINE ART FROM MANUAL 6880902Z30-D, PAGE 4-6

Troubleshooting Flow Chart

for Microprocessor

August, 1996 6880904Z07-O 5-5

INSERT LINE ART FROM MANUAL 6880902Z30-D, PAGE 4-7

Troubleshooting Flow Chart for VCO

5-6 6880904Z07-O August, 1996

Battery Filter Board

Flex Circuit

Section 616

Section 7

Component Location Diagrams,

Schematic Diagrams, and Parts Lists for

MAEPF-25508-O

Parts List: 0180702Y89 Battery Filter Board

REFERENCE

SYMBOL

C2, 3, 4 2113740A43 39pF ±5%; 50V

L1, 2 2484657R01 Ferrite Bead

F1 6505663R044 4Amp.

MOTOROLA

PART NO.

CAPACITOR, Fixed:

COIL, RF:

FUSE:

DESCRIPTION

MAEPF-25509-O

63A81084C55-O

Internal Speaker

Speaker Common

Ground

Internal Microphone

External Select

External Speaker

External Microphone

Battery Filter Board and Flex Circuit

General

Controller components and transceiver components are all part of a single circuit board. Two circuit boards (component location diagrams), VHF and UHF, show transceiver and controller components.

Controller

Speaker Common

External Microphone

Ground

External Speaker

External Select

Any differences in the controller between the VHF and UHF RF bands will be on the controller schematic and parts list.

Transceiver

Each bandsplit (VHF or UHF) will include 12.5 and 25KHz channel spacing. Any differences between 12.5 and 25KHz channel spacing will be denoted on the particular VHF or UHF schematic and corresponding parts list.

Schematic Notes

1. Unless otherwise indicated, resistor values are in ohms, capacitor values are in picofarads, and inductor values are in microfarads.

2. Non-polarized capacitors are chip-type unless otherwise indicated.

MAEPF-25510-O

INT SPKR 1

SPKR COM 2

GND 3

INT MIC 4

EXT SEL 5

EXT SPKR 6

EXT MIC 7

RADIO SIDE

CONNECTOR

GND

EXT MIC

EXT SEL

EXT SPKR

SPKR COM

LS1

INT SPKR

MK1

INT MIC

EXT SPK

EXT SEL

GND

EXT M

Parts List: Flex Circuit

REFERENCE

SYMBOL

C1 2113740A41 33pF ±5%; 50V LS1 5005589U05

MK1 5013920A04

MOTOROLA

PART NO.

CAPACITOR, Fixed:

SPEAKER

MICROPHONE:

Electret

DESCRIPTION

3. Polarized capacitors are titanium chip-type unless otherwise indicated.

4. “NU” means that a component is not used.

5. DC voltages are measured with a high impedance (10 megohm) DC voltmeter.

6. AC voltages are measured with a high impedance AC RMS voltmeter.

7. All voltages measured are in the receive mode unless indicated otherwise. Indications are as follows: (R) Receive Mode (T) Transmit Mode

8. Measured in the receive mode with an on-channel unmodulated signal at a level of -20dBm.

9. Measured in the receive mode with an on-channel unmodulated signal at a level of -20dBm, modulated with 1kHz at 3kHz deviation (for 20/25kHz models) or 1.5kHz deviation (for 12.5kHz models), measured with an AC RMS voltmeter.

10. Same as note 8, except with volume control adjusted for 500 milliwatts (2.82 volts RMS across a 16ohm load connected to the external speaker jack.

11. Measured in the transmit mode with a 1kHz, 11mV RMS signal applied to the external microphone input.

Battery Filter Board and Flex Circuit Circuit Board Details, Schematic Diagrams, and Parts Lists

August 13, 1996 6880904Z07-O

6-1

MAEPF-25481-O

Component Location Diagram for HLD9440A and HLD9441A VHF, 146-174MHz, Transceiver and Controller

6-2

6880904Z07-O August 13, 1996

MAEPF-25482-O

Schematic Diagram for HLD9440A and HLD9441A

VHF, 146-174MHz, Transceiver Section

August 13, 1996 6880904Z07-O

6-3

MAEPF-25483-O

Component Location Diagram for HLE9480A and HLE9481A UHF, 438-470MHz, Transceiver Section

6-4

6880904Z07-O August 13, 1996

MAEPF-25484-O

Schematic Diagram for HLE9480A and HLE9481A

UHF, 438-470MHz, Transceiver Section

August 13, 1996 6880904Z07-O

6-5

Schematic Diagram for Controller Section

6-6

6880904Z07-O August 13, 1996

Parts List: Controller Components (for all bandsplits)

Controller Components (for all bandsplits) Controller Components (for all bandsplits) Controller Components (for all bandsplits)

REFERENCE

SYMBOL

C401 2113740A41 33pF C402 2113740G16 3.6pF C403 NU C404 2113740A37 22pF C405 2160521G37 0.1uF C406 2113741A45 10nF C407 2311049A40 2.2uF C408 2160521G37 0.1uF C409, 410 2113740A59 150pF, UHF Only C412 2311049A07 1uF C413 2311049A05 0.47uF C414 2160521G37 0.1uF C415 2113741A37 4.7nF C416 2160521G37 0.1uF C421 2311049A05 0.47uF C423 2311049A05 0.47uF C427 2160521G37 0.1uF C428 2113740A71 470pF C429 2160521G37 0.1uF C430 2113740A71 470pF C431 2113741A47 12nF C432 2113741A59 39nF C433 2311049A05 0.47uF C434, C435 2160521G37 0.1uF C436 2113740A71 470pF C437 2113741A59 39nF C440 2113740A71 NU C442, C443 2113740A79 1nF C445 2113741A33 3.3nF C447 2160521G37 0.1uF C449 2311049A07 1uF C451 2113741A49 15nF C452 2311049J11 4.7uF C453 NU C454 thru C457 2160521G37 0.1uF C459, C460 2113741A21 1nF C462 2113740A79 1nF C463 2160521G37 0.1uF C466 thru C468 2113741A21 1nF C469 2113741A37 4.7nF C472 thru C476 2113741A21 1nF, VHF

C477 NU C478 2113740A79 1nF C481 2113740A59 150pF C482 2113741A59 39nF C483, C484 2113740A71 470pF C500 2113741A37 4.7nF C501 2113741A45 10nF

MOTOROLA

PART NO.

2113740A59 150pF, UHF

DESCRIPTION

CAP A CIT OR, Fixed pF +/-5%; 50V unless stated

REFERENCE

SYMBOL

C503 2113741A45 10nF C504 2311049J11 4.7uF C505, C506 2311049A07 1uF C507, C508 2160521G37 0.1uF C513 2311049A07 1uF C514 2113740A79 1nF C515 2311049A07 1uF C516 2113743F12 33nF C517 2113743F08 33nF C518 2160521G37 0.1uF C519 2160521G37 0.1uF C520 2113740A59 150pF C903 2311049J27 10uF UHF Only

CR401 4880939T01 Shottky Barrier CR402 thru CR404 4813833C07 Dual CR405 4880107R01 Rectiﬁer CR406 NU CR407, CR408 4813833C07 Dual CR409 NU

DS401 4805729G49 Light-emitting

J5 0180488E01 Controls Flex Connector J6 0180965Z01 B+, SCI Connector

L401 2460578C43 33 L403 thru L406 2462587Q42 390nH L503 2462587Q42 390nH

P1 Option Board Solder Pads

PB401 4080485C05 MON PB402 4080485C05 OPT 2 PB403 4080485C05 PTT

Q401 4880214G02 NPN Q406 thru Q409 4805128M16 SOT, MMBT3906 Q501 4802245J04 PNP

R401 0660076H31 1.8M R402 0660076A65 4.7k R403 0660076B01 100k R404 0660076B07 180k R406 0660076B01 100k R407 0660076A49 1k R408 thru R411 0660076A89 47k R412 0660076A31 180 R413 0660076A45 680 R414 thru R417 0660076A73 10k

MOTOROLA

PART NO.

DESCRIPTION

DIODE: (see note)

DIODE:

CONNECTOR, Receptacle:

COIL, Inductor

CONNECTOR, Receptacle:

SWITCH, Pushbutton:

TRANSISTOR: (see note)

RESISTOR, Fixed: +/-5%; 1/ 8W: unless otherwise stated

REFERENCE

SYMBOL

R418, R419 0660076B01 100k R420 0660076A73 10k R421 0660076B07 180k R422 thru R424 0660076B01 100k R425 0660076B09 220k R426 0660076B06 160k R429 0660076B17 470k R431 0660076A90 51k R432 0660076A80 20k R433 0660076A73 10k R434 0660076B01 100k R442 0660076H31 1.8M R443 0660076B01 100k R444 0660076A80 20k R445 0660076H31 1.8M R451 0660076A57 2.2k R452 0660076B07 180k R453 0660076A57 2.2k R454 0660076B01 100k R455 0660076A84 30k R456 0660076A65 4.7k R457 0660076A93 68k R458 0660076A69 6.8k R459 0660076B23 820k R460 1880143S02 Potentiometer R461 0660076A09 22 R462 0660076B17 470k R463 0660076A89 47k R464 0660076A55 1.5k R465 0660076B18 510k R466 0660076A65 4.7k R468, R469 0660076A73 10k R470 0660076A25 100 R471 0660076A73 10k R472, R473 0660076A25 100 R474, R475 0660076A73 10k R476 0660076B01 100k R478 0660076A84 30k R479 0660076A73 10k R484 0660076A68 6.2k R486 0660076B01 100k R487 0660076A73 10k R491 0660076A83 27k R492 0660076A70 7.5k R493 0660076B13 330k R494 0660076B01 100k R497 0660076A41 470 R498 NU R503 0660076A37 330 R504 0660076B07 180k R505 0660076B06 160k

MOTOROLA

PART NO.

DESCRIPTION

REFERENCE

SYMBOL

R506 0660076A82 24k R513 0660076B06 160k R514 0660076A73 10k R515 0660076A07 18 R516 0660076A89 47k R517 NU R518 0660076A80 100k

U401 5180598D01 Processor U402 5105165R77 AFIC U405 5180932W01 Linear Op. Amp. U406 5102198J23 Compactor, LM2903D, 50T/R U409 5105165R65 Audio PA U410 5180159R01 Dual transistor, NPNs U411 5180633C01 5V Regulator

VR401 4880140I15 5.6V VR900 4805117Y01 Dual VR901 NU VR902 NU

Y401 4880113R01 7.9488MHz

MOTOROLA

PART NO.

DESCRIPTION

INTEGRATED CIRCUIT: (see note)

DIODE, Zener: (see note

CRYSTAL: (see note)

)

NOTE: For optimum performance, order replacement diodes, transistors, and integrated circuits by Motorola part number only. When ordering crystal units, specify type number, frequency, and Motorola part number.

August 13, 1996 6880904Z07-O

6-7

Parts List: HLD9440A and HLD9441A, 146-174MHz VHF T ransceiver

HLD9440A and HLD9441A, 146-174MHz VHF Transceiver Board HLD9440A and HLD9441A, 146-174MHz VHF Transceiver Board HLD9440A and HLD9441A, 146-174MHz VHF Transceiver Board HLD9440A and HLD9441A, 146-174MHz VHF Transceiver Board HLD9440A and HLD9441A, 146-174MHz VHF Transceiver Board

REFERENCE

SYMBOL

C28, C29 2113740A48 51pF C30, C31 2113740A79 1nF C33 2113740A24 6.8pF C34 2113741A45 10nF C35 2113740A53 82pF C36 2113740A18 4.3pF C51 2113740A53 82pF C53 2113740A37 22pF C54 2113740A33 15pF C55 2160521G37 0.1uF C56 thru C58 2113740A36 20pF C59, C60 2160521G37 0.1uF C61 2113741A25 1.5nF C62 2311049A05 0.47uF C63 2113740A48 51pF C64 2113740A72 510pF C65 2113741A45 10nF C66 2160521G37 0.1uF C67 2311049J11 4.7uF C68 2113741A59 39nF C69 2311049J07 3.3uF C70 2160521G37 0.1uF C71 2311049J25 10uF C73 2113740A32 13pF C74 2113740A42 36pF C75 2113740A17 3.9pF C77 2113740A14 3pF C78 0660076M01 0 C79 2113740A34 16pF C80 NU C81 thru C84 2160521G37 0.1uF C85 thru C87 2113740A59 150pF C101, C102 2311049A07 1uF C103 2113740A53 82pF C104 2113740A63 220pF C105 2311049J25 10uF C106 2113740A63 220pF C107 2113741A59 39nF C111 2113740A71 470pF C112 2113740A37 22pF C113 2113740A42 36pF C114 2113740A48 51pF C115 2113740A39 27pF C116 2113740A79 1nF C117 2113740A27 8.2pF C118 2113740A71 470pF C119 2113740A36 20pF C120, C121 2113740A71 470pF C122 2113740A35 18pF

MOTOROLA

PART NO.

CAPACITOR, Fixed: pf +/-5%; 50V: unless otherwise stated

DESCRIPTION

REFERENCE

SYMBOL

C151, C152 2113740A71 470pF C153 2160521G37 0.1uF C154 2113740A71 470pF C156 2113740A71 470pF C157, C158 2113741A45 10nF C159 2113740A71 470pF C163, C164 2113740A71 470pF C165 2113741A45 10nF C166 2311049A05 0.47uF C167, C168 2113741A59 39nF C201 NU C202, C203 2113741A45 10nF C204 2311049J27 10uF C205 2113740A63 220pF C206 2113740G46 47pF C207, C208 2311049J11 4.7uF C209 2113740A71 470pF C210, C211 2311049J11 4.7uF C212 2113741A21 1nF C214 2311049A07 1uF C215 2113741A39 5.6nF C216 2160521G37 0.1uF C217 2311049J11 4.7uF C218 2113741A21 1nF C219 thru C221 2113740A59 150pF C222 2113741A21 1nF C223 2113740A41 33pF C224 2113740A79 1nF C226 2113740A14 3pF C227 2113740A03 1pF C228 2113740A59 150pF C229 NU C230 2160521G37 0.1uF C231 2113741A45 10nF C232 NU C233 2113740G24 6.8pF C235 2113741A51 18nF C236 2113740A71 470pF C237, C238 2113740A55 100pF C251 2113740A33 15pF C252 2113740A30 11pF C253 2113740A34 16pF C254 2113740A03 1pF C255 2113740A37 22pF C256, C257 2113740A79 1nF C258 NU C259 2113740A79 1nF C260 2113740A27 8.2pF C261 2113740A34 16pF C262 2113740A28 9.1pF C263 2113740A03 1pF

MOTOROLA

PART NO.

DESCRIPTION

REFERENCE

SYMBOL

C264 2113740A32 13pF C265 2160521G37 0.1uF C266 2113740A79 1nF C268, C269 2113740A79 1nF C270 2113740A17 3.9pF C271 2113740A19 4.7pF C272 2113740A16 3.6pF C273 2113740A79 1nF C275 2113740A79 1nF C276 2113741A45 NU C278, C279 2311049A03 0.22uF C280 2113740A79 1nF C281 2113740A71 470pF C284 2113740A10 2pF C285 2113740A71 470pF

CF51 9180098D06 Ceramic, 3WR (25kHz) CF52 9180098D05 Ceramic, 3WR (25kHz)

CLP1 thru CLP8 4280138R02 Butterﬂy

CR2 4880174R01 Ring Mixer CR51 4880154K03 Dual CR101, CR102 4880973Z02 Pin CR201, CR202 4813833C07 Dual CR203 4805649Q04 Varactor CR252, CR253 4805649Q04 Varactor CR255 4805649Q04 Varactor

J1 3980515C02 Antenna Contact J2 0180117S05 Antenna Jack

JU51 NU

L9 2462587X45 22nh L11 2462587X51 68nH L51 2483411T63 0.15 L52 2462587X61 470nH L53 2462587N69 1.2uH L54 NU L55 2483411T75 1.5 L58 2483411T74 1.2 L101thru L103 2411087B24 0.68uH L104 2484657R01 Ferrite Bead L106 2411087B24 0.68uH L107 2405486C76 7T L108 2405318D12 7T L109 2405486C76 7T L111 2405835C03 5T L112 2405486C77 7T L201 2462587N69 1.2uH

MOTOROLA

PART NO.

FILTER:

CLIP:

DIODE: (see note)

CONNECTOR, Receptacle:

JUMPER:

COIL, Inductor

DESCRIPTION

REFERENCE

SYMBOL

L203 2462587N69 1.2uH L204 2462587X56 180nH L251, L252 2462587N69 1.2uH L253 2480145S05 5 1/2 turns, Ferrite Core L254 2462587X55 150nH L255 thru L257 2462587N69 1.2uH L258 2480145S04 4 1/2 turns, Ferrite Core L259 2462587N69 1.2uH L260 2483411T62 27nH L261 2462587X55 150nH L262 2462587X46 27nH L267 2462587X56 180nH L268 2462587N69 1.2uH

Q51 4813827A07 NPN, Small Signal Q151 4880214G02 NPN Q152 4813822A10 PNP, 60V, 10Amp. Q153 4880214G02 NPN Q154 4880141I03 PNP Q155, Q156 4880214G02 NPN Q405 4805128M16 SOT, MMBT3906 (RH)

R51 0660076A18 51 R52 0660076A85 33k R53 0660076A75 12k R54 0660076A56 2k R55 0660076A25 100 R57 0660076B04 130k R58 0660076A76 13k R59 0660076A93 68k R60 0660076A70 7.5k R64 0660076A67 5.6k R66 0660076A47 820 R67 0660076A69 6.8k R68 0660076A25 100 R69 0660076A73 10k R101 0680106R01 0.1; 1W R102 0660076A29 150 R103 0660076A22 75 R104 0660076A36 300 R105 0660076A07 18 R106 0660076A36 300 R107 0611077A18 4.7 R108 0660076A22 75 R151 0660076E91 56k R152 0660076F01 100k R153 0660076A09 22 R154 0660076F01 100k R155 0660076E91 56k R156 0660076A63 3.9k

MOTOROLA

PART NO.

DESCRIPTION

TRANSISTOR:

RESISTOR, Fixed

unless otherwise stated

(see note)

: +/-5%; 1/8W:

MOTOROLA

PART NO.

R157 0660076A55 1.8k R158, R159 0660076A31 180 R160, R161 0660076A45 680 R162 0660076A27 120 R166 0660076A31 180 R167 0660076A78 16k R168 0660076B01 100k R169 0660076A73 10k R170 NU R171 0660076A90 51k R172 0660076A81 22k R173 NU R174 0660076B01 100k R175 0660076A68 6.2k R179 0660076A38 360 R201 0660076A18 51 R202 0660076A49 1k R203 0660076B06 160k R204 0660076B02 110k R205, R206 0660076A57 2.2k R207 0660076A65 4.7k R211 0660076A89 47k R212 0660076A73 NU R215 0660076A49 1k R216 0660076A82 24k R251 0660076A95 82k R253 0660076A60 3k R254 0660076A73 10k R257 0660076A89 68k R258 0660076A25 100 R260, R261 0660076A33 220 R263 0660076A70 7.5k R264 0660076A01 10 R265 0660076I17 4.7 R438 0660076A61 3.3k

SH100 2680521D02 Synthesizer Front SH101 2680520D02 VCO Front SH103 2680518D02 Synthesizer Back SH104 2680692C03 Mixer Back SH105 2680519D02 VCO Back

T1, T2 2580163M03

U1 0180706Y82 Front End Module U51 5180207R01 IFIC U101 5180111R02 Power Ampliﬁer U151 5180932W01 Linear Op. Amp. U152 5105226P38 DA Converter U201 5105457W61 Synthesizer

DESCRIPTION

SHIELD:

TRANSFORMER:

INTEGRATED CIRCUIT: (see note)

REFERENCE

SYMBOL

U251 5105414S84 VCO Buffer

Y51A, Y51B 9180112R05 45.1MHz Filter Y53 4880008K02 44.85MHz Y201 4880114R02 16.8MHz Clock

MOTOROLA

PART NO.

DESCRIPTION

CRYSTAL:

6-8

6880904Z07-O August 13, 1996

Parts List: HLE9480A and HLE9481A, 438-470MHz UHF T ransceiver

HLE9480A and HLE9481A, 438-470MHz UHF Transceiver HLE9480A and HLE9481A, 438-470MHz UHF Transceiver HLE9480A and HLE9481A, 438-470MHz UHF Transceiver HLE9480A and HLE9481A, 438-470MHz UHF Transceiver HLE9480A and HLE9481A, 438-470MHz UHF Transceiver

REFERENCE

SYMBOL

C13 2113740A59 150pF C28 2113740A38 24pF C29 2113740A33 15pF C30 2113740A59 150pF C33 2113740A07 1.5pF C34 2113741A45 10nF C36 2113740A18 4.3pF C37 NU C51 2113740A53 82pF C53 2113740A37 22pF C54 2113740A33 15pF C55 2160521G37 0.1uF C56 2113740A36 20pF C57, C58 2113740A36 NU C59, C60 2160521G37 0.1uF C61 2113741A25 1.5nF C62 2311049A05 0.47uF C63 2113740A48 51pF C64 2113740A72 510pF C65 2113741A45 10nF C66 2160521G37 0.1uF C67 2311049J11 4.7uF C68 2113741A59 39nF C69 2311049J07 3.3uF C70 2160521G37 0.1uF C71 2311049J25 10uF C73 2113740A32 13pF C74 2113740A42 36pF C75 2113740A17 3.9pF C77 2113740A14 3pF C78 0660076M01 0 C79 2113740A34 16pF C80 NU C81 thru C84 2160521G37 0.1uF C85 thru C87 2113740A59 150pF C101 2311049J11 4.7uF C102 2311049A07 1uF C103 2113740A59 150pF C104 2113740A41 33pF C105 2311049J25 10uF C106 2113740A59 150pF C107, C108 2113741A51 18nF C109 2113740A41 33pF C110, C111 2113740A59 150pF C112 2113740A27 8.2pF C113, C114 2113740A31 12pF C115 2113740A17 3.9pF C116 2113740A59 150pF C117 NU

MOTOR OLA

PART NO.

DESCRIPTION

CAPACITOR, Fixed: pf +/-5%; 50V: unless otherwise stated

REFERENCE

SYMBOL

C118 2113740A46 47pF C119 2113740A03 NU C120, C121 2113740A59 150pF C122 2113740A36 20pF C123, C124 NU C125 2113740A24 NU C151, C152 2113740A59 150pF C153 2160521G37 0.1uf C154 2113740A59 150pF C156 2113740A59 150pF C157, C158 2113741A45 10nF C159 thru C164 2113740A59 150pF C165 2113741A45 10nF C166 2311049A05 0.47uF C201 NU C202, C203 2113741A45 10nF C204 2311049J27 10uF C205 2113740A63 220pF C206 2113740G46 47pF C207, C208 2311049J11 4.7uF C209 2113740A59 150pF C210, C211 2311049J11 4.7uF C212 2113741A21 1nF C214 2311049A07 1uF C215 2113741A39 5.6nF C216 2160521G37 0.1uF C217 2311049J25 10uF C218 2113741A21 1nF C219 thru C221 2113740A59 150pF C222 2113741A21 1nF C223 2113740A41 33pF C224 2113740A59 150pF C226 2113740A13 2.7pF C227 2113740A03 1pF C228 2113740A59 150pF C229 NU C230 2160521G37 0.1uf C231 2113741A45 10nF C232 NU C233 2113740G24 6.8pF C235 2113741A51 18nF C236 2113740A59 150pF C237, C238 2113740A55 100pF C251 2113740A21 5.6pF C252 2113740A21 5.6pF C253 2113740A40 30pF C254 2113740A11 2.2pF C255 2113740A28 9.1pF C256, C257 2113740A59 150pF C258 NU C259 2113740A59 150pF

MOTOROLA

PART NO.

DESCRIPTION

REFERENCE

SYMBOL

C260 2113740A21 5.6pF C261 2113740A20 5.1pF C262 2113740A27 8.2pF C263 2113740A05 1.2pF C264 2113740A24 6.8pF C265 2160521G37 0.1uf C266, C267 2113740A59 150pF C268 2113741A21 1nF C269 2113740A59 150pF C270 2113740A09 1.8pF C271, C272 2113740A21 5.6pF C273 2113740A59 150pF C275 2113740A59 150pF C276 2113741A45 10nF C278, C279 2311049A03 0.22uF C280, C281 2113740A59 150pF C282 2113740A71 470pF C283 2113740A59 150pF C284 2113740A03 1pF

CF51 9180098D06 Ceramic, 3WR (25kHz) CF52 9180098D05 Ceramic, 3WR (25kHz)

CLP1 thru CLP8 4280138R02 Butterﬂy

CR2 4880174R01 Ring mixer CR51 4880154K03 Dual CR101, CR102 4880973Z02 Pin CR201, CR202 4813833C07 Dual CR203 4805649Q04 Varactor CR251 4805649Q02 Varactor CR253 4805649Q02 Varactor CR255 4805649Q02 Varactor

J1 3980515C02 Antenna contact J2 0180117S05 Antenna jack

JU51 NU

L9 2462587X43 15nH L10 2483411T63 0.15 L11 2462587X46 27nH L51 2483411T63 0.15 L52 2462587X61 470nH L53 2462587N69 1.2uH L54 NU L55 2483411T75 1.5 L58 2483411T74 1.2 L101 thru L103 2411087A19 0.27 L104 2484657R01 Ferrite Bead L105 2484657R01 Ferrite Bead

MOTOROLA

PART NO.

DESCRIPTION

FILTER:

CLIP:

DIODE: (see note)

CONNECTOR, Receptacle:

JUMPER:

COIL: Inductor

REFERENCE

SYMBOL

L106 2411087A19 0.27 L107 thru L109 2483035N76 Coil, airwound L111 2483035N13 5T L112 2483035N76 Coil, airwound L113 2462587X54 0.12 L201 2462587X22 390nH L203 2462587X22 390nH L204 2462587X48 39nH L251, L252 2462587X22 390nH L253 2480145S07 1 1/2 turn, brass core, white L254 2462587X49 47nH L255 2462587X22 390nH L256, L257 2462587X61 .47 L258 2480145S08 2 1/2 turn, brass core, violet L259 2462587X22 390nH L260 2462587X46 27nH L261 2462587X47 33nH L262 2462587X43 15nH L267 2462587X50 56nH L268 2462587X22 390nH

Q51 4813827A07 NPN, Small signal Q151 4880214G02 NPN Q152 4813822A10 PNP, 60V, 10Amp Q153 4880214G02 NPN Q154 4880141L03 PNP Q155, Q156 4880214G02 NPN Q251 4813827A07 NPN, Small signal Q405 4805128M16 SOT, MMBT3906 (RH) 48G22

R5 0660076A30 160 R6 0660076A01 10 R51 0660076A18 51 R52 0660076A85 33k R53 0660076A75 12k R54 0660076A56 2k R55 0660076A25 100 R57 0660076B04 130k R58 0660076A76 13k R59 0660076A93 68k R60 0660076A70 7.5k R64 0660076A67 5.6k R66 0660076A47 820 R67 0660076A69 6.8k R68 0660076A25 100 R69 0660076A73 10k R101 0680106R01 0.1 1W R102 0660076A37 330 R104 0660076A31 180 R105 0660076A11 27

MOTOROLA

PART NO.

DESCRIPTION

TRANSISTOR: (see note)

RESISTOR, Fixed: +/-5%; 1/8W: unless otherwise stated

REFERENCE

SYMBOL

R106 0660076A31 180 R151 0660076E91 56k R152 0660076F01 100k R153 0660076A09 22 R154 0660076F01 100k R155 0660076E91 56k R156 0660076A63 3.9k R157 0660076A55 1.8k R158, R159 0660076A31 180 R160, R161 0660076A45 680 R162 0660076A27 120 R166 0660076A31 180 R167 0660076A78 16k R168 0660076B01 100k R169 0660076A73 10k R170 NU R171 0660076A90 51k R172 0660076A81 22k R173 NU R174 0660076B01 100k R175 0660076A68 6.2k R179 0660076A38 360 R201 0660076A23 82 R202 0660076A57 2.2k R203 0660076B09 220k R204 0660076B01 100k R205 0660076A61 3.3k R206 0660076A57 2.2k R207 0660076A65 4.7k R211 0660076A89 47k R212 0660076A73 NU R215 0660076A49 1k R216 0660076A82 24k R251 0660076A83 27k R252 0660076A73 10k R253 0660076A53 1.5k R254 0660076A73 10k R255 0660076A74 11k R256 0660076A53 1.5k R257 0660076A84 30k R258 0660076A25 100 R260, R261 0660076A33 220 R262 0660076a39 390 R263 0660076a87 39k R438 0660076a61 3.3k

SH100 2680521D02 Synthesizer Front SH101 2680520D02 VCO Front SH102 2680522D02 Harmonic Filter SH103 2680518D02 Synthesizer Back SH104 2680692C03 Mixer Back

MOTOROLA

PART NO.

DESCRIPTION

SHIELD:

REFERENCE

SYMBOL

SH105 2680519D02 VCO Back

T1, T2 2580163M03

U1 0180707Y42 Front End Module U51 5180207R01 IFIC U101 5113829D04 Power Ampliﬁer U152 5105226P38 DA Converter U201 5105457W61 Synthesizer U251 5105414S84 VCO Buffer

Y51A, Y51B 9180112R05 45.1MHz Filter Y53 4880008K02 44.85MHz IF Y201 4880114R02 16.8MHz Clock

MOTOROLA

PART NO.

DESCRIPTION

TRANSFORMER:

INTEGRATED CIRCUIT: (see note)

CRYSTAL: (see note)

August 13, 1996 6880904Z07-O

6-9

Parts List: GP350 Basic Mechanical

)

(

REFERENCE

SYMBOL

1 2

3 4 5 6 7 8

9 10 11 12 13 14 15 16 17

18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

MOTOROLA

PART NO.

HLN8255 HNN9360

HNN9361 13-80463E01 39-80571E01 39-80457E01 32-80545C01 01-80708Y67 18-80143S02 42-80190R04 26-80465E01 39-80546B02 75-80437C01 01-80520E02 50-05589U05 15-80484E01 13-80458E01 36-80477E01 36-80477E02 36-80476E01

13-80471E01 13-80471E02 61-80968Y01 32-80960Y01 33-80469E01 75-80466E01 13-80467E01 15-80450E01

HLN9208 75-80575E01 50-13920A04 14-80577C01 35-80998Z04 55-80438B01 41-05944K01 40-80485C08

HLN9480

HLN9951

HLN9208 75-80470E01 15-80450E02 42-80126S01 03-00136783 40-80502B01 39-80559E01 26-80692C02 26-80519D01 26-80518D01 26-80522D01 26-80520D01 26-80521D01

DESCRIPTION

CLIP, Spring Belt BATTERY (Also see Accessories) BATTERY, FM ESCUTCHEON, Battery Contact CONTACT, Programming CONTACT, Battery GASKET, Chassis CHASSIS POTENTIOMETER, V olume CLIP, Locking; 4 Used SHIELD, Main CONTACT, Speaker PAD, Speaker FLEX, Speaker/Mic SPEAKER COVER, Universal ESCUTCHEON, Universal KNOB, Freq. 16 Pos. KNOB, Freq. 2 Pos. KNOB, V olume ANTENNA (See Accessories) ESCUTCHEON, 16 Pos ESCUTCHEON, 2 Pos LIGHTPIPE SEAL, Control; 2 Used LABEL, Name KEYPAD, Push-To-Talk BEZEL, Push-To-Talk HOUSING, Radio ASSY, Analog Scrambler (Optional PAD, Option Board MICROPHONE BOOT, Microphone FELT, Speaker LATCH, Battery SPRING, Coil; 2 Used SWITCH, Snap (PB401, 2, 3) LABEL, FM Intrinsic ASSY, DTMF Encode (Optional) ASSY, Analog Scrambler w/DTMF KEYPAD, 16 Key HOUSING, DTMF CLIP. P.A. SCREW; 2 Used SWITCH, Frequency (SW401T) CONTACT, Antenna (J1) SHIELD, Mixer SHIELD, VCO Front SHIELD, Synthesizer, Front SHIELD, Harmonic Filter (UHF Onl SHIELD, Synthesizer Rear SHIELD, VCO Rear

19 20

21 22 23

MAEPF-25232-O

Exploded Mechanical View and Parts List (Basic)

6-10

6880904Z07-O August 13, 1996

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 51

August 13, 1996 6880904Z07-O

HLN9960A DTMF Circuit Board Detail

6-11

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 52

HLN9960A DTMF Schematic Diagram and Parts List

6-12

6880904Z07-O August 13, 1996

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 53

GP300 / GP350 / P110 Chargers & Power Supplies

Battery Charger Rate/Voltage Power Supply

HTN9630 1 Hour / 120 V 25-80162R01 HTN9702 10 Hour / 120 V 25-80955Z02 HTN9748 (6 unit) 1 Hour / 120 V 25-80427B01 HTN9938 (6 unit) 1 Hour / 100 V 25-80427B01 HTN9802 1 Hour / 220 V 25-80162R02 (European Plug) HTN9804 10 Hour / 220 V 25-80955Z03 (European Plug) HTN9811 (6 unit) 1 Hour / 220 V 25-80427B01 (European Plug) HTN9803 1 Hour / 240 V 25-80162R03 (U. K. Plug) HTN9805 10 Hour / 240 V 25-80955Z04 (U. K. Plug) HTN9812 (6 unit) 1 Hour / 240 V 25-80427B01 (U. K. Plug)

August 13, 1996 6880904Z07-O

Battery Chargers

Single and Multi-Unit Rapid Rate (1 Hour)

6-13

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 54

Battery Chargers Single and Multi-Unit Rapid Rate (1 Hour)

6-14

6880904Z07-O August 13, 1996

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 55

August 13, 1996 6880904Z07-O

Battery Chargers

Standard Rate (10 Hour)

6-15

INSERT PAGE SIZE, ARTWORK, AND TEXT FROM MANUAL: 6880902Z30-D, PAGE 56

Battery Chargers Standard Rate (10 Hour)

6-16

6880904Z07-O August 13, 1996

16 Ω

MK1

L2 L1

C2 C3

LS1

Parts List: HMN9041A Remote Speaker/Microphone

REFERENCE

SYMBOL

C1 2113740A53 82pF, +/-5%, 50V C2 2113740A67 330pF, +/-5%, 50V C3 2113741A53 .022uF, +/-5%, 50V C4 2113741A69 0.1uF, +/-5%, 50V

L1 thru L4 2462575A02 680nH, +/-10%

R1 0660076M01 0 Ω

LS1

S1 3905834K06 Dome, PTT

MK1 0180703Y69

‡Provided by remote speaker microphone vendor

MOTOROLA

PART NO. DESCRIPTION

CAPACITOR, Fixed: uF +/-10%; 100V; unless otherwise stated

COIL, RF:

RESISTOR, Fixed: Ω unless otherwise stated

SPEAKER:

5005910P05

SWITCH:

MICROPHONE:

Pin #2 (White)

Pin #4 (Blue)

Pin #5 (None)

Pin #1 (Red)

Pin #3 (Black)

August, 1996 6880904Z07-O

Schematic Diagram and Parts List for

HMN9041A Remote Speaker/Microphone

6-17

Parts List: HMN9041A Remote Speaker/Microphone

REFERENCE

SYMBOL

1 0105953N42 Front housing, items 1 thru 5 1 2 3305259Q01 Nameplate, Motorola 1 3 4505182Q01 Lever, PTT 1 4 3501152J01 Grille, cloth 1 5 1105461R01 Adhesive 1 6 0180492E01 Acc. Conn. Cable Assembly 1 7 0180703Y67 PCB: includes electrical parts 1 8 3905834K06 Switch: dome, PTT (S1) 1

9 3205231Q01 Seal, dome 1 10 1405219Q01 Boot, microphone 1 11 0180703Y69 Microphone assembly 1 12 5005910P05 Speaker (LS1) 1 13 7505283Q02 Pad, speaker 1 14 3205690R01 Gasket 1 15 6405689R01 Plate, housing mounting 1 16 0300139982 Screw, Phillips; 2-56 x 5/32" 3 17 1505172Q01 Housing, back 1 18 0484345A06 Washer 3 19 0305137Q02 Screw, Phillips 3 20 0105959N54 Belt clip assembly 1 21 0300139982 Screw, Phillips; 2-56 x 5/32" 4 22 5405258Q25 Label, Kit 1

MOTOROLA

PART NO. DESCRIPTION QTY

Exploded View and Parts List for HMN9041A Remote Speaker/Microphone

6-18

6880904Z07-O August, 1996

MOTOROLA GP350 User Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

General

WARNING

CAUTION

FCC Safety Information

FMRC Approved Equipment

Repair of FMRC Approved Products

Repair

Relabeling

Do Not Substitute Options or Accessories

Remove Battery

Remove Belt Clip from Battery

Remove Chassis

Remove the Main Board

Re-assembly of Radio

Microcomputer

Receiver

Transmitter

Frequency Generation Circuitry

Battery Filter Board

Flex Circuit

General

Controller

Transceiver

Schematic Notes

Parts List: GP350 Basic Mechanical

Parts List: HMN9041A Remote Speaker/Microphone