tti Tech PMR-446 - User Manual

service
manual
PMR-446 Radio
TX-446
TTI Tech

Summary

SECTION 1 SPECIFICATIONS

SECTION 2 INSIDE VIEWS

SECTION 3 CIRCUIT DESCRIPTION

3-1 MICROPROCESSOR; CONTROL SECTION

Details the microprocessor's role in monitoring inputs, handling changes, and controlling radio functions.

3-2 VCO;SYNTHESIZER SECTION

Explains the Temperature-Compensated Crystal Oscillator, Voltage Controlled Oscillator, and synthesizer circuits.

3-3 TRANSMITTER SECTION

Describes the RF power amplifier, antenna switching, power control, and audio circuits for transmission.

3-4 RECEIVER SECTION

Covers the receiver front end, local oscillator, mixer, FM detector, squelch, and audio circuits.

3-5 BATTERY SECTION

Details the battery connection, voltage monitoring, and battery saver mode functionality.

SECTION 4 ADJUSTMENT PROCEDURES

4-1 GENERAL

Provides channel and frequency information required for proper radio alignment and calibration.

4-2 SYNTHESIZER;TRANSMITER

Covers procedures for checking and adjusting the synthesizer and transmitter parameters.

4-2-1. VCO Check

Procedure to check the Voltage Controlled Oscillator output voltage at TP1.

4-2-2. Frequency Adjustment

Steps to adjust the transmitter frequency using CV301 for a frequency counter.

4-2-3. Modulation Adjustment

Procedure for adjusting modulation deviation using RV501 and setting audio bandwidth.

4-2-4. VOX Adjustment

Steps for adjusting the VOX sensitivity in both high and low settings via software.

4-3. TRANSMITTER ALIGNMENT

Guidance on performing transmitter alignment, including power output adjustments.

4-3-1. POWER Adjustment

Procedure to adjust the transmitter output power to specified levels using CPS.

4-4. RECEIVER ALIGNMENT

Procedures for aligning the receiver, including sensitivity, squelch, and battery alert settings.

4-4-1. Receiver sensitivity confirmation

Steps to confirm the receiver's sensitivity by setting signal generator levels and checking SINAD.

4-4-2 Squelch Adjustment

Procedure to adjust squelch sensitivity for both normal and tight settings using CPS.

4-4-3 Battery Alert Adjustment

Steps to adjust battery low and over alert thresholds using DC power supply and CPS.

SECTION 5 PART LIST

5-1. ELECTRICAL PART LIST

Detailed list of all electrical components, including reference designators and descriptions.

5-2. MECHANICAL PART LIST

Detailed list of all mechanical components, including reference designators and descriptions.

SECTION 6 MECHANICAL DISASSEMBLY

SECTION 7 BOARD LAYOUT

7-1 MAIN PCB (Top side)

Diagram showing the component placement on the top side of the main PCB.

7-1 MAIN PCB (Bottom side)

Diagram showing the component placement on the bottom side of the main PCB.

7-2 SWITCH PCB (Top side)

Diagram showing the component placement on the top side of the switch PCB.

7-2 SWITCH PCB (Bottom side)

Diagram showing the component placement on the bottom side of the switch PCB.

7-3 BATTERY PCB (A Top side)

Diagram showing the component placement on the top side of Battery PCB A.

7-3 BATTERY PCB (A Bottom side)

Diagram showing the component placement on the bottom side of Battery PCB A.

7-3 BATTERY PCB (B Top side)

Diagram showing the component placement on the top side of Battery PCB B.

7-3 BATTERY PCB (B Bottom side)

Diagram showing the component placement on the bottom side of Battery PCB B.

SECTION 8 BLOCK DIAGRAM

SECTION 9 CIRCUIT DIAGRAM

9-1 MAIN PCB

Detailed circuit schematic for the main printed circuit board.

9-2 BATTERY PCB

Detailed circuit schematic for the battery printed circuit board.

tti Tech PMR-446 Specifications

General

Brand	tti Tech
Model	PMR-446
Category	Radio
Language	English