Ericsson LBI-39175A User Manual

SERVICE SECTION

ORION™

136-174 MHz Dual Bandwidth

SYNTHESIZED TWO-WAY FM RADIO

TABLE OF CONTENTS

DESCRIPTION ........................................................................................................................... 2

INITIAL MEASUREMENTS ..................................................................................................... 2

TRANSMITTER........................................................................................................... 2

RECEIVER.................................................................................................................... 2

MAINTENANCE........................................................................................................................ 3

PREVENTIVE MAINTENANCE ................................................................................ 3

DISASSEMBLY PROCEDURE................................................................................... 4

LBI-39175A

Page

ALIGNMENT PROCEDURES................................................................................................... 7

INTRODUCTION......................................................................................................... 7

TRACKING DATA....................................................................................................... 9

TEST FREQUENCIES.................................................................................................. 9

SETTING TRACKING DATA.....................................................................................10

TRANSMITTER ALIGNMENT.................................................................................................11

PA TRANSISTOR REPLACEMENT...........................................................................11

RECEIVER ALIGNMENT .........................................................................................................12

TEST EQUIPMENT REQUIRED ................................................................................12

ADJUSTMENT PROCEDURES..................................................................................12

SQUELCH ADJUSTMENT..........................................................................................13

TROUBLESHOOTING GUIDE .................................................................................................13

INTRODUCTION.........................................................................................................13

MICROPHONICS.........................................................................................................13

SERVICEABLE PARTS...............................................................................................14

DIAGNOSTIC PROCEDURES ..................................................................................................15

ADDITIONAL TOOLS REQUIRED............................................................................16

ERROR CODES............................................................................................................19

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BI-39175A

DESCRIPTION

This section contains the information required to service the ORION VHF Dual Bandwidth two-way FM radio. Included are disassembly procedures, alignment procedures, and troubleshooting information (see Table of Contents).

This radio is adjusted by setting personality parameters stored in the radio's computer memory. Therefore, all radio alignment procedures require the use of a Personal Computer (IBM PC or equivalent), along with a Programming Interface TQ3370, and an ORION PC Programming Cable TQ3377. PC Programming Software Version 4.00 or later is also required.

This radio is designed to be serviced by replacement of modules and/or circuit boards. As such, there are very few serviceable component parts contained on any of the circuit boards within the radio. Normally, defective boards should be replaced, and returned to an Authorized Service Center. Any serviceable parts are listed in the troubleshooting guide for the individual circuit boards.

INITIAL MEASUREMENTS

After the radio has been installed as described in the Installation Manual, the following measurements should be made by a certified electronics technician, and recorded for future reference:

TRANSMITTER

• RF Power into 50 ohm resistive load

• Forward Power into antenna

• Reflected Power from antenna

• Carrier Frequency

• Modulation Deviation

RECEIVER

• 12 dB SINAD Sensitivity from FM signal

generator

LBI-39175

MAINTENANCE

PREVENTIVE MAINTENANCE

NOTE

To ensure high operating efficiency, and to prevent mechanical and electrical failures from interrupting system operations, routine checks should be made of all mechanical and electrical equipment at regular intervals. This preventive maintenance should include the checks as listed in Table 1, Maintenance Checks.

Table 1 - Maintenance Checks

MAINTENANCE CHECKS INTERVAL

CONNECTIONS - Ground connections and connections to the voltage source should be periodically checked for tightness. Loose or poor connections to the power source will cause excessive voltage drops and faulty operation. When ground connections are not made directly to the battery, the connection from the battery to vehicle chassis must be checked for low impedance. A high impedance may cause excessive voltage drops and alternator noise problems.

Every

months

ELECTRICAL SYSTEM - Check the voltage regulator and alternator or generator periodically to keep the electrical system within safe and economical operating limits. Overvoltage is indicated when the battery loses water rapidly. Usage of 1 or 2 ounces of water per cell per week is acceptable for batteries in continuous operation. A weak battery will often cause excessive noise or faulty operation.

MECHANICAL INSPECTION - Since mobile units are subject to constant shock and vibration, check for loose plugs, nuts, screws, and parts to make sure that nothing is working loose. Be sure that all screws are properly torqued.

ANTENNA INSPECTION - The antenna, antenna base, and all contacts should be kept clean and free from dirt or corrosion. If the antenna or its base should become coated or poorly grounded, loss of radiation and a weak signal will result.

ALIGNMENT - The transmitter and receiver measurements should be checked periodically. Refer to the applicable Alignment Procedure and troublesho oting sheet for typical voltage readings.

FREQUENCY CHECK - Check transmitter frequency and deviation, as required by the FCC. Normally, these checks are made when the unit is first put into operation, after the first six months, and once a year thereafter.

Required

Every 6

months

Every 6

months

Required

BI-39175A

DISASSEMBLY PROCEDURE

To Remove the Unit from the Mounting Bracket

1. Remove Microphone, Power, and Accessory/Remote Control Cables, as required.

2. Remove the lock screws at the side of the radio unit, using a No. 20 TORX

3. Pull the radio, and remove the mounting bracket.

To Gain Access to the Circuitry for Servicing

RF Power Amplifier Module

1. Remove the waterproof cover on the bottom of the module, using #20 TORX

mounting screws are captive.

2. Remove the inner shield by pulling the attached handle.

Transceiver (TXRX) Module

1. Remove the waterproof top and bottom covers, using a #20 TORX



are located on the bottom of the module. The screws on the bottom cover are captive.



driver.



driver. Note that the four

driver. Four co ver mounting screws

NOTE

The VCO/Synthesizer circuitry is exposed by removing the screws from the shield casting, also located on the bottom of the module. However, this is not recommended, except on extreme situations. If the shield is removed, it should be replaced using the exact screw torque and installation sequence given in LBI-38909.

Control Unit (Front Mounted)

1. Expose the Logic/Audio/455 kHz IF circuitry according to Steps 1 and 2 in

Module

section.

2. Disconnect Flex Circuit PC2 from Connector J701, by carefully disengaging the locking tab from each side of the connector with a jeweler's screwdriver or tweezers. Use extreme care to avoid damaging the plating runs or surface-mounted components on the printed wire board (PWB) during this procedure.

3. Turn the radio upside down, and disengage the two mounting screws, using a #10 TORX

sure to engage the screws in the captivation threads on the Transceiver chassis. Do this by pulling each screw upwards with tweezers or needle nose pliers, while simultaneously turning the screw

counterclockwise with the TORX 38909 for details.

4. Disengage the control unit from the Transceiver chassis using a pivoting motion about the top ed ge of the Transceiver chassis.

Transceiver (TXRX)



driver. Be



driver. See LBI-

2. To expose the Logic/Audio/455 kHz IF circuitry, remove the shield on top of the module by pulling the attached handle.

5. Disengage the four captive screws on the rear cover, using a #10 TORX



driver. Slide the rear cover off the Front Panel Assembly, using care to avoid damaging the black "O-Ring" moisture gasket

3. To expose the Exciter/RX Front End circuitry, remove the shield on the bottom of the module by

attached to the rear cover. Note that the Flex Circuit PC2 slides through a slot opening on the rear cover.

pulling the attached handle.

Control Head (Remote Mounting)

1. Disconnect Remote Control and Accessory cables, using a small flat bladed screwdriver.

2. Remove the two side mounting screws from the mounting bracket. Carefully remove the Control Head assembly from the bracket.

3. Disengage the four captive screws on the rear half (also known as the Remote Interface Adapter, or RIA) of the Control Head. Slide the two halves apart, using care to avoid damaging the black "ORing" moisture gasket attached to the RIA.

4. Disconnect Flex Circuit PC2 from Connector J2, by carefully disengaging the locking tab from each side of the connector with a jeweler's screwdriver or tweezers. Use extreme care to avoid damaging plating runs or surface-mounted components in the PWB during this procedure.

LBI-39175

NOTE

For re-assembly of the Control Units (Front and Remote Mounting) Revision "A" or later, be sure the black "O-Ring" is lubricated properly with "HIVAC-G" silicone grease. (See Figures 1A and 1B for intructions.)

Steps:

1. Remove dust and dirt from the black O-Ring gasket.

2 Apply proper amount of the silicone grease to cloth.

To Re-Assemble Unit after Servicing

Essentially follow the reverse of the preceding

instructions. However, in order to preserve moisture seals, be sure to follow the EXACT torque and sequencing specifications for screw engagement during reassembly. These specifications are given in LBI-38909.

3. Put the silicone grease on throughout the surface of the black O-Ring gasket evenly. (see Figures 1A and 1B)

CAUTION

No fibers of the cloth must remain on the gasket after silicone is applied.

4. Wipe out protruded silicone grease from the Rear/RIA Cover.

BI-39175A

Figure 1A - Front Mount Control Unit "O-Ring" Lubrication

Figure 1B - Remote Mount Control Unit "O-Ring" Lubrication

ALIGNMENT PROCEDURES

INTRODUCTION

All operations of this radio are controlled by an embedded digital computer, which is programmed with a personality unique to the customer. In order to align and test the radio, it must be programmed with a specific test personality, which will allow conventional operation on certain test frequencies. Furthermore, certain commands, known as Test Mode Commands, cause the radio to perform specific test functions. These will be noted as required in the following alignment and troubleshooting instructions.

In order to program an ORION personality, the radio and control unit must first be connected to a Personal Computer via a PC Programming Cable and hardware Programming Interface TQ3370 in one of the configurations shown in Figures 2 and 3. Accessories may be connected to the appropriate Accessory Cable 19B802554P1-P4 as needed.

The PC must be equipped with the PC Programming Software Version 4.0 or later. It is assumed in this manual that the Service Technician is familiar with the operation of the PC Programming Software Programs. Consult the PC Programming Software manuals for further details regarding this software.

LBI-39175

CAUTION

Before bench testing the radio, be sure of the output voltage characteristics of your bench power supply.

To protect the transmitter power output transistors from possible instant destruction, the following input voltages must not be exceeded

Transmitter unkeyed: 16.5 Volts Transmitter keyed 16.3 Volts (50 ohms resistive load) Transmitter keyed 14.0 Volts (no load or non-resistive load):

These voltages are specified at the normal vehicle battery terminals of the radio and take the voltage drop of standard cables into account. The voltage limits shown for a non-optimum load is for "worst case" conditions. For antenna mismatches likely to be encountered in practice, the actual limit will approach the 16.3 Volt figure.

Routine transmitter tests should be performed at EIA Standard Test Voltages (13.6 VDC for loads of 6 to 16 amperes; 13.4 VDC for loads of 16 to 36 amperes). Input voltages must not exceed the limits shown, even for transient peaks of short duration.

Many commonly used bench power supplies cannot meet these requirements for load regulation and transient voltage suppression. Bench supplies which employ "brute force" regulation and filtering (such as Lapp Model 73) may be usable when operated in parallel with a 12 Volt automotive storage battery.

BI-39175A

Figure 2 - ORION Programming Configurations (USA)

Figure 3 - ORION Programming Configurations (EURO)

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