Parts List
Table Of Contents
- 1GENERAL
- 2SYSTEM OVERVIEW
- 2.1Transmitter Operation
- 2.2Frequency Selection
- 2.2.1Synthesizer Transmitter
- 2.3Transmitter Assembly and Adjustment
- 2.3.1Complete Transmitter Alignment
- 2.3.2Frequency Change
- 2.3.3Output Power Adjustment
- 2.3.4Deviation Setting
- 2.3.5Setting RF Alarm Thresholds
- 2.4Recommended Test Equipment List
- 2.5Repair Note
- 2.6Printed Circuitboard Numbering Convention
- 3ILLUSTRATIONS
- 4PARTS LIST
- 5REVISION HISTORY
- TRANSMITTER MAIN BOARD
- 1GENERAL
- 2THEORY OF OPERATION
- 2.1 Transmitter Main Board
- 2.1.1General
- 2.1.2Transmitter Push-To-Talk
- 2.1.2.1Microphone PTT
- 2.1.2.2PTT With Time-Out-Timer
- 2.1.2.3PTT No Time-Out-Timer
- 2.1.2.4Optional Relay
- 2.1.2.5PTT Output
- 2.1.2.6PTT Voltage Switching
- 2.1.2.7Transmitter Standby Modes
- 2.1.3Audio Circuits
- 2.1.3.1Microphone Audio
- 2.1.3.2Received Audio
- 2.1.4Channel Selection
- 2.1.4.1Synthesized Transmitter
- 2.1.4.2Crystal Controlled Transmitter
- 2.1.5Amplifier Circuits
- 2.1.6Time-Out-Timer Circuitry
- 2.2MT-3 Front Panel Board
- 2.3MT-3 Audio Processor (Version 1.6)
- 2.3.1General
- 2.3.2Power Requirements
- 2.3.3Audio Processor Turn-on Time
- 2.3.4Audio Processor Signals
- 2.3.4.1Audio Processor Outputs
- 2.3.4.2Audio Processor Modulation Output
- 2.3.4.3Audio Processor Low Frequency / Direct Mod. Output
- 2.3.4.4Audio Processor Inputs
- 2.3.4.5Audio Processor Microphone Input
- 2.3.4.6Audio Processor Balanced Input
- 2.3.4.7Audio Processor Auxiliary Input
- 2.3.4.8Audio Processor Subtone Inputs
- 2.3.4.9Audio Processor Direct Modulation Input
- 2.4MT-3 Audio Processor (Version 1.8)
- 2.4.1General
- 2.4.2Power Requirements
- 2.4.3Audio Processor Turn-on Time
- 2.4.4Audio Processor Signals
- 2.4.4.1Audio Processor Outputs
- 2.4.4.2Audio Processor Modulation Output
- 2.4.4.3Audio Processor Low Frequency / Direct Mod. Output
- 2.4.4.4Audio Processor Inputs
- 2.4.4.5Audio Processor Microphone Input
- 2.4.4.6Audio Processor Balanced Input
- 2.4.4.7Audio Processor Auxiliary Input
- 2.4.4.8Audio Processor Subtone Inputs
- 2.4.4.9Audio Processor Direct Modulation Input
- 2.5Low Frequency Modulation
- 3TRANSMITTER ALIGNMENT
- 3.1General
- 3.2Repair Note
- 3.3Printed Circuitboard Numbering Convention
- 3.4Recommended Test Equipment List
- 3.5Standard Factory Settings and Jumper Configuration
- 3.5.1MT-3 Transmitter Board Factory Configuration
- 3.5.2MT-3 Audio Processor Factory Configuration (Version 1.6)
- 3.6MT-3 Transmitter Board Alignment
- 3.6.1General
- 3.6.2MT-3 Transmitter Board Test Points
- 3.7Module Installation and Removal
- 3.8MT-3 Audio Processor Alignment (Version 1.6)
- 3.8.1General
- 3.8.2MT-3 Audio Processor Standard Deviation Adjustment
- 3.9Standard Factory Settings and Jumper Configuration
- 3.9.1MT-3 Audio Processor Factory Configuration (Version 1.8)
- 3.10MT-3 Audio Processor Alignment (Version 1.8)
- 3.10.1General
- 3.10.2MT-3 Audio Processor Standard Deviation Adjustment
- 3.11Low Frequency Modulation Configuration
- 3.11.1MT-3 Transmitters
- 3.11.2MT-3 Transmitter Audio Processors
- 3.11.3Synthesizer and Crystal Controlled Oscillator
- 3.11.4Tuning the Transmitter
- 4TRANSMITTER INTERCONNECT PIN DEFINITIONS
- 5ILLUSTRATIONS AND SCHEMATIC DIAGRAMS
- 5.1Transmitter Block Diagram
- 5.2Transmitter Main Board Electrical Assembly
- 5.2.1Transmitter Main Board Top Side Component Layout
- 5.2.2Transmitter Main Board Bottom Side Component Layout
- 5.2.3Transmitter Main Board Schematic Diagram
- 5.3Front Panel Board
- 5.3.1Front Panel Board Component Layout
- 5.3.2Front Panel Board Schematic
- 5.4Audio Processor Electrical Assembly (Version 1.6)
- 5.4.1Audio Processor Component Layout
- 5.4.2Audio Processor Schematic Diagram
- 5.5Audio Processor Electrical Assembly (Version 1.8)
- 5.5.1Audio Processor Component Layout
- 5.5.2Audio Processor Schematic Diagram
- 6PARTS LISTS
- 6.1Transmitter Main Board Parts List
- 6.1.1Transmitter Main Board Electrical Parts List
- 6.1.2Transmitter Main Board Mechanical Parts List
- 6.1.3MT-3 Front Panel Board Electrical Parts List
- 6.2MT-3 Audio Processor Parts List (Version 1.6)
- 6.2.1MT-3 Audio Processor Electrical Parts List (Version 1.6)
- 6.3MT-3 Audio Processor Parts List (Version 1.8)
- 6.3.1MT-3 Audio Processor Electrical Parts List (Version 1.8)
- 7REVISION HISTORY
- AUDIO PROCESSOR
- 1 FM AUDIO PROCESSOR
- 2 SIGNALS
- 3 THEORY OF OPERATION
- 4 ALIGNMENT
- 5 TROUBLESHOOTING - TEST EQUIPMENT NEEDED
- 6 TEMPERATURE COMPENSATION
- 7 ILLUSTRATIONS, TABLES AND SCHEMATIC DIAGRAMS
- 8 FM AUDIO PROCESSOR PARTS LIST
- 9 AM AUDIO PROCESSOR
- 9.1 Introduction
- 9.2 Performance Specifications
- 9.3 Audio Specifications
- 9.4 Audio Circuits
- 9.5 Power Requirements
- 9.6 Transmitter Standby Modes
- 9.7 Audio Circuitry
- 9.8 AM Audio Processor Factory Configuration
- 9.9 AM Audio Processor Alignment
- 9.10 AM Audio Processor Electrical Parts List
- 9.11 AM Audio Processor Component Layout
- 9.12 AM Audio Processor Schematic Diagram
- 10 REVISION HISTORY
- VHF AMPLIFIER
- 1GENERAL
- 2THEORY OF OPERATION
- 3VT-3/150 AMPLIFIER ALIGNMENT
- 3.1General
- 3.2Repair Note
- 3.3Recommended Test Equipment List
- 3.4Printed Circuitboard Numbering Convention
- 3.5Standard Factory Settings and Jumper Configuration
- 3.6VT-3/150 Amplifier Alignment
- 3.6.1General
- 3.6.2VT-3/150 Amplifier Adjustment
- 3.6.2.1General Set-Up
- 3.6.2.2Output Power Alarm (Forward Power)
- 3.6.2.3Output Power
- 3.6.2.4Antenna VSWR Alarm (Reverse Power)
- 3.6.2.5Antenna VSWR Overload
- 3.6.2.6Procedure Verification
- 4ILLUSTRATIONS AND SCHEMATIC DIAGRAMS
- 5PARTS LISTS
- 6REVISION HISTORY
- ENHANCED AM/FM SYNTHESIZER
- 1. GENERAL
- 2. THEORY OF OPERATION
- 2.1 Internal Power and Control (Digital Board)
- 2.2 Synthesizer Analog Circuitry (Analog Board)
- 2.2.1 Common Analog Board Circuitry
- 2.2.2 29 - 71.4 MHz Analog Board Circuitry
- 2.2.3 118 - 159.4 MHz Multichannel AM Analog Board Circuitry
- 2.2.4 128 - 174 MHz Analog Board Circuitry
- 2.2.5 406 - 470 MHz Analog Board Circuitry
- 2.3 Synthesizer Digital Circuitry (Digital Board)
- 2.4 Frequency Control
- 2.4.1 BCD Switch Frequency Control
- 2.4.2 Frequency Select Handle Frequency Control
- 2.5 Synthesizer Base and Frequency Increment Table
- 2.6 5.0/6.25 kHz Channelization.
- 2.7 8.333 kHz Channelization.
- 2.8 12.5 kHz Channelization.
- 3. SYNTHESIZER ALIGNMENT
- 3.1 General
- 3.2 Repair Note
- 3.3 Recommended Test Equipment
- 3.4 OS(R/T)-3(A/H) Synthesizer Factory Configuration
- 3.5 OS(R/T)-3(A/H) Synthesizer Alignment
- 3.5.1 General
- 3.5.2 Synthesizer Test Points
- 3.5.3 Synthesizer Removal and Installation
- 3.5.4 Circuit Board Removal
- 3.5.5 Frequency Adjustment and Channel Selection
- 3.5.5.1 VHF OS(R/T)-3H 29 - 71.4 MHz VCO Alignment
- 3.5.5.2 VHF OS(R/T)-3A 118 - 159.4 MHz Alignment
- 3.5.5.3 VHF OS(R/T)-3H 128 - 174 MHz VCO Alignment
- 3.5.5.4 UHF OS(R/T)-3H 406 - 470 MHz VCO Alignment
- 3.5.5.5 Reference Frequency Alignment
- 3.5.6 Jumper Configuration
- 4. ILLUSTRATIONS AND SCHEMATIC DIAGRAMS
- 4.1 OS(R/T)-3H 29 - 71.4 MHz Analog Board Diagrams
- 4.1.1 OS(R/T)-3H 29 - 71.4 MHz Analog Board Component Layout (Bottom)
- 4.1.2 OS(R/T)-3H 29 - 71.4 MHz Analog Board Component Layout (Top)
- 4.1.3 OS(R/T)-3H 29 - 71.4 MHz Analog Board Schematic Diagram
- 4.2 OS(R/T)-3A 118 - 159.4 MHz Analog Board Diagrams
- 4.2.1 OS(R/T)-3A 118 - 159.4 MHz Analog Board Component Layout (Bottom)
- 4.2.2 OS(R/T)-3A 118 - 159.4 MHz Analog Board Component Layout (Top)
- 4.2.3 OS(R/T)-3A 118 - 159.4 MHz Analog Board Schematic Diagram
- 4.3 OS(R/T)-3H 128 - 174 MHz Analog Board Diagrams
- 4.3.1 OS(R/T)-3H 128 - 174 MHz Analog Board Component Layout (Bottom)
- 4.3.2 OS(R/T)-3H 128 - 174 MHz Analog Board Component Layout (Top)
- 4.3.3 OS(R/T)-3H 128 - 174 MHz Analog Board Schematic Diagram
- 4.4 OS(R/T)-3H 406 - 470 MHz Analog Board Diagrams
- 4.4.1 OS(R/T)-3H 406 - 470 MHz Analog Board Component Layout (Bottom)
- 4.4.2 OS(R/T)-3H 406 - 470 MHz Analog Board Component Layout (Top)
- 4.4.3 OS(R/T)-3H 406 - 470 MHz Analog Board Schematic Diagram
- 4.5 OS(R/T)-3(A/H) Digital Board Diagrams
- 4.5.1 OS(R/T)-3(A/H) Digital Board Component Layout (Bottom)
- 4.5.2 OS(R/T)-3(A/H) Digital Board Component Layout (Top)
- 4.5.3 OS(R/T)-3(A/H) Digital Board Schematic Diagram
- 5. PARTS LISTS
- 5.1 OS(R/T)-3H 29 - 71.4 MHz Analog Board Electrical Parts List
- 5.2 OS(R/T)-3A 118 - 159.4 MHz Analog Board Electrical Parts List
- 5.3 OS(R/T)-3H 128 - 174 MHz Analog Board Electrical Parts List
- 5.4 OS(R/T)-3H 406 - 470 MHz Analog Board Electrical Parts List
- 5.5 OS(R/T)-3(A/H) Digital Board Electrical Parts List
- 5.6 OS(R/T)-3(A/H) Synthesizer Mechanical Parts List
- 6. REVISION HISTORY
- VHF CHANNEL DESIGNATION TABLES
VHF Enhanced Transmitter Instruction Manual VT-3 132 - 174 MHz
2-1
2
SYSTEM OVERVIEW
2.1
Transmitter Operation
Several
modules are
integrated
by the VT-3
Transmitter
Main board to pr
ovide
the
complete
transmitter.
The
Transmitter
Main
Board,
Front Panel Board and Audio Processor are
generic
in
that they apply to all
transmitter
models. The Front Panel Board and Audio Processor are soldered
directly
to the
Transmitter
Main Board and are
treated
collectively
in the
Transmitter
Main Board
Manual. The
operating
frequency and power range is
determined
by the
choice
of
Amplifier
and
Frequency Synthesizer
Module,
which
plugs in to the
Transmitter
Main Board and can be changed
with
minimal
effort.
Circuitry
and jumpers on the
Transmitter
Main Board control the
operation
of
all modules and the
operation
of the
transmitter,
overall.
Technical
details
and a
complete
description
of
transmitter
operation
can be found in the
Transmitter
Main Board Manual.
The VT-3 132 - 174 MHz
transmitter
requires two power supplies; a
regulated
+9.5
Vdc supply
and a
+13.8
Vdc
supply,
the
latter
of
which
is
connected
only to the
Amplifier
Module. The
(nominally)
+13.8
Vdc supply's range is
+11
Vdc to
+16
Vdc. For the 0.5 to 2.0 Watt
transmitters,
there is no current drawn on the 13.8 Vdc supply. For the 2.0 to 8.0 Watt
transmitters,
the current drawn from the
+13.8
Vdc supply
(while
transmitting
at the rated power) is
approximately
1000 mA
with
temperature,
operating frequency and power supply
voltage.
The
current drawn by the 13.8 Vdc line should not
exceed
1500 mA. The
+9.5
Vdc current drawn by
all
transmitter
models
while
transmitting
at the rated power is
approximately
1300 mA and should
not
exceed
1500 mA. The VT-3
Transmitter
has four
different
standby modes that trade-off
standby current
consumption
for start-up speed. The standby modes are
determined
by three
jumpers (refer to the MT-3
Transmitter
Main Board Manual): jumper J6
which
always
turns on the
'+9.5
Vdc
Switched'
supply,
jumper J7
which
selects the power source for the MT-3
Audio
Processor and jumper J18
which
selects the
enable
line for the
OS-3H150
Synthesizer Module.
• MODE 1: Jumper J6 out
- the audio processor is
switched
by a PTT signal
- the synthesizer module is
switched
by a PTT signal
- standby
current:
Typically
7 mA
- start-up
time:
Typically
50 ms