Leader LT 4441 User manual

LT 4441 / LT 4442
CHANGEOVER
INSTRUCTION MANUAL

TABLE OF CONTENTS
1. INTRODUCTION ........................................................................................................ 1
1.1 Scope of Warranty .................................................................................................................. 1
1.2 Operating Precautions ............................................................................................................ 1
1.2.1 Power Supply Voltage...................................................................................................... 1
1.2.2 Maximum Allowable Input Voltage ................................................................................... 1
1.2.3 Shorting and Applying External Input to the Output Connectors...................................... 2
1.2.4 Mechanical Shock............................................................................................................ 2
1.2.5 Electrostatic Damage....................................................................................................... 2
1.2.6 Rack Mounting................................................................................................................. 2
1.2.7 Warming Up..................................................................................................................... 2
2. SPECIFICATIONS ...................................................................................................... 3
2.1 General ................................................................................................................................... 3
2.2 Features.................................................................................................................................. 3
2.3 Specifications.......................................................................................................................... 4
2.3.1 I/O Connectors................................................................................................................. 4
2.3.2 I/O Characteristics ........................................................................................................... 4
2.3.3 Types of Input Signals ..................................................................................................... 5
2.3.4 Signal Switching .............................................................................................................. 5
2.3.5 Error Detection................................................................................................................. 6
2.3.6 Key Lock.......................................................................................................................... 7
2.3.7 External Control Connectors............................................................................................ 7
2.3.8 General Specifications ..................................................................................................... 7
3. NAMES AND FUNCTIONS OF PARTS ...................................................................... 8
3.1 Front Panel ............................................................................................................................. 8
3.2 Rear Panel.............................................................................................................................. 9
3.3 Side Panel .............................................................................................................................. 9
3.4 Top Panel.............................................................................................................................. 10
4. HOW TO USE............................................................................................................11
4.1 Turning the Power ON .......................................................................................................... 11
4.2 Attaching the Cover Inlet Stopper ......................................................................................... 12
4.3 DIP Switch Settings .............................................................................................................. 13
4.3.1 Setting Method............................................................................................................... 14
4.3.2 Input Signal Settings...................................................................................................... 15
4.3.3 Error Detection Reference Settings ............................................................................... 16
4.3.4 Error Detection Level Settings (User setting)................................................................. 17
4.3.5 Signal Switch Time Settings .......................................................................................... 18
4.3.6 Operation Mode and Standby Time Settings ................................................................. 19
4.4 Signal I/O .............................................................................................................................. 20
4.5 Configuring the LT 4441/4442............................................................................................... 21
4.5.1 Enabling the Key Lock ................................................................................................... 21

4.5.2 Switching the Output Signal........................................................................................... 21
4.5.3 Setting Automatic Signal Switching................................................................................ 22
4.5.4 Error Display and Resetting........................................................................................... 23
5. EXTERNAL INTERFACE.......................................................................................... 24
5.1 Remote-control Connector.................................................................................................... 24
6. CALIBRATION AND REPAIRS ................................................................................. 26

I
GENERAL SAFETY SUMMARY
■Read This before Using the Instrument
This instrument should only be used by persons with sufficient knowledge of electronics who
thoroughly understand the contents of this manual.
This instrument is not designed or manufactured for households or ordinary consumers.
If a person without sufficient knowledge of electronics uses this instrument, it may be damaged,
and the user may be injured. Such a person should not use this instrument unless they are
supervised by a person who does possess such knowledge.
■Note about Reading This Manual
The contents of this manual contain specialized terminology and may be difficult to understand. If
you have any questions about the contents of this manual, please contact your local LEADER
agent.
■Symbols and Terms
The following symbols and terms are used in this instruction manual and on the instrument to
indicate important warnings and notes.
<Symbol>
This symbol appears in this instruction manual and on the instrument to indicate
an area where improper handling could result in personal injury, damage to the
instrument, or malfunction of the instrument or devices connected to it.
When you encounter this symbol on the instrument, be sure to refer to the
information in this instruction manual that corresponds to the area that the
symbol marks.
<Term>
Ignoring the precautions that this term indicates could lead to death or serious
injury.
<Term>
Ignoring the precautions that this term indicates could lead to personal injury or
damage to the instrument.

II
GENERAL SAFETY SUMMARY
Read the warnings and information below thoroughly to avoid death, personal injury, and damage and
deterioration of the instrument.
■Warnings Concerning the Case and Panels
Do not remove the instrument's case or panels for any reason except for setting DIP switches.
Touching the internal components of the instrument could lead to fire or electric shock.
Also, do not allow foreign materials, such as liquids, combustible matter, and metal, to enter the
instrument. Turning the instrument ON when such materials are inside it could lead to fire,
electric shock, damage to the instrument, or some other accident.
■Warnings Concerning the Power Source
Do not use a power source with a voltage other than the rated power source voltage for the
instrument. Doing so could lead to fire.
Confirm the voltage of the commercial power source before you connect the AC power cord.
Only use a power source whose frequency is 50/60 Hz.
Only use the supplied power cord. Using any other power cord with this instrument could lead
to fire. If the supplied power cord is damaged, stop using it, and contact your local LEADER
agent.
Using a damaged power cord could lead to electrical shock or fire. When removing the plug
from the power outlet, do not pull on the cord. Pull from the plug.
There is no power switch on this instrument. Only use this instrument after you have secured a
method that enables you to shut off the power source in an emergency.
■If You Notice Something Wrong during Operation
If you notice smoke, flame, a strange smell, or something else that is wrong with the instrument
while you are operating it, a fire may occur. Remove the power cord from the outlet to stop
operation immediately. After making sure that fire has not spread anywhere, contact your local
LEADER agent.
■Installation Environment
• Operating Temperature Range
Use this instrument in a 0 to 40 °C environment. Using the instrument with its vents blocked
or in a high temperature environment could lead to fire.
Drastic changes in temperature, such as might be caused by moving the instrument between
two rooms with different temperatures, can damage the instrument by causing condensation
to form within it. If there is a possibility that the instrument has condensation within it, wait for
approximately 30 minutes before turning ON the power.

III
GENERAL SAFETY SUMMARY
Read the warnings and information below thoroughly to avoid death, personal injury, and damage and
deterioration of the instrument.
■Cautions Concerning the Input and Output Connectors
To avoid damaging the instrument, only apply signals to the input connectors that conform to
the specifications in this instruction manual.
Also, do not apply signals to the output connectors. Doing so could damage the instrument.
■If You Will Not Use the Instrument for an Extended Period of Time
If you will not use the instrument for an extended period of time, remove the power plug from
the outlet.
• Operating Humidity Range
Use this instrument in an environment whose relative humidity is 85 % or less where there is
no threat of condensation forming.
Also, do not operate this instrument with wet hands. Doing so could lead to electric shock or
fire.
• Do Not Operate in an Explosive Atmosphere
Using this instrument in an environment where flammable gasses, explosive gasses, or
steam is emitted or stored could lead to an explosion or fire. Do not use the instrument in
such an environment.
• Do Not Insert Foreign Materials
If foreign materials, such as metal, flammable objects, or liquid are allowed into the
instrument (through the vents for example), fire, electric shock, damage to the instrument, or
some other accident may result.

IV
GENERAL SAFETY SUMMARY
■Routine Maintenance
When you clean the instrument, remove the power plug from the outlet.
Do not use thinner or benzene when you clean the instrument's case, panels, or knobs. Doing so
could lead to paint chipping and the corrosion of plastic components. To clean the case, panels,
and knobs, use a soft cloth with mild detergent, and wipe gently. While cleaning, make sure that
foreign materials, such as water and detergent, do not enter the instrument. If liquid or a metal
object enters into the instrument, fire or electric shock may result.
■About the European WEEE Directive
This instrument and its accessories are subject to the European WEEE Directive. Follow the
applicable regulations of your country or region when discarding this instrument or its accessories.
(WEEE stands for Waste Electrical and Electronic Equipment.)
Follow the warnings and precautions that have been listed in this section to use the instrument
correctly and safely. Precautions are also contained in various other sections of this instruction manual.
To use the instrument correctly, be sure to follow those precautions as well.
If you have any questions or comments about this instruction manual, please contact your local
LEADER agent.

1. INTRODUCTION
1
1. INTRODUCTION
Thank you for purchasing this LEADER instrument. To use this instrument safely, read this
instruction manual thoroughly, and make sure that you know how to use the instrument
properly.
If some point about the operation of this instrument is still unclear after you have read this
instruction manual, refer to the contact information on the back cover of the manual to contact
LEADER, or contact your local LEADER agent.
After you have finished reading this manual, keep it in a convenient place so that you can refer
to it when necessary.
1.1 Scope of Warranty
This LEADER instrument has been manufactured under the strictest quality control
guidelines.
LEADER shall not be obligated to furnish the following free services during the warranty
period.
1 Repair of malfunction or damages resulting from fire, natural calamity, or improper
voltage applied by the user.
2 Repair of an instrument that has been improperly repaired, adjusted, or modified by
personnel other than a factory-trained LEADER representative.
3 Repair of malfunctions or damages resulting from improper use.
4 Repair of malfunctions caused by devices other than this instrument.
5 Repair of malfunctions or damages without the presentation of a proof of purchase or
receipt bill for the instrument.
1.2 Operating Precautions
1.2.1 Power Supply Voltage
Confirm the voltage of the commercial power source before you connect the power plug to
it. The operating voltage range is 90 to 250 VAC. Only use a power source that supplies a
voltage within the operating voltage range and has a frequency of 50/60 Hz.
1.2.2 Maximum Allowable Input Voltage
The maximum signal voltage that can be applied to the input connectors is indicated below.
Do not apply excessive voltage to the connectors. Doing so may damage the instrument or
lead to injury.
Table 1-1 Maximum allowable input voltage
Input Connector Maximum Allowable Input Voltage
Channels 1 to 3 ±5 V
Channels 4 to 10 ±1.5 V
CH11 0 V or +5 V

1. INTRODUCTION
2
1.2.3 Shorting and Applying External Input to the Output Connectors
Do not short the output connectors. Doing so may damage the instrument.
Do not apply an external signal to the output connectors. Doing so may damage the
instrument and devices that are connected to it.
1.2.4 Mechanical Shock
This instrument contains sensitive components, so it may be damaged if it is dropped or
otherwise exposed to a strong shock.
1.2.5 Electrostatic Damage
Electronic components can be damaged by static discharge. Static electricity can build up
in the core wire of a coaxial cable. Before connecting a coaxial cable to the instrument,
short the core wire of the cable with the external conductor.
1.2.6 Rack Mounting
If you are mounting this instrument on a rack, be sure to provide additional support for the
instrument. If you only use the included rack supports to mount the instrument, the
instrument case may be deformed, or the instrument may fall. This instrument can be
mounted on an EIA 19-inch rack.
The recommended slide rails are shown in the following table. To mount this instrument on
a rack, two slide rails, one for the left side and one for the right side of the instrument, are
required.
Table 1-2 Recommended slide rails
Stock Number Manufacturer
C-203-16 Settsu Metal Industrial Co., Ltd.
KC-251-16 TAKIGEN MFG CO., LTD.
MODEL 203-16 Accuride Japan Co., Ltd.
1.2.7 Warming Up
To ensure more accurate measurements, turn ON the instrument approximately 30 minutes
before you intend to use it to allow its internal temperature to stabilize.

2. SPECIFICATIONS
3
2. SPECIFICATIONS
2.1 General
The LT 4441/4442 is a changeover unit that automatically switches the signal from the
primary signal to the backup signal when problems are detected in the primary signal. Two
systems of input signals (primary and backup) are connected to the LT 4441/4442, and the LT
4441/4442 detects errors in the amplitude of the primary input signal.
A single LT 4441/4442 provides 11 channels. Depending on the configuration of the internal
switches, SDI (channels 1 to 3 only), NTSC/PAL analog black burst, tri-level sync, AES/EBU
digital audio, and word-clock signals can be received by the channels.
Relays are used to switch channels 1 to 3. Electrical switches are used to switch channels 4
to 11. In addition to the electrical switches, channels 4 to 11 are also equipped with
high-speed, error detection circuits. When trouble such as a signal interruption occurs, the LT
4441/4442 can quickly switch to a signal that has a small amount of glitches.
If a switch occurs from a primary signal to a backup signal, the LT 4441/4442 indicates the
channel that caused the problem on the panel LED.
The LT 4442 is a short version of the LT 4441 changeover unit. The depth of the LT 4442 is
400 mm. You can combine the LT 4441/4442 with multi-format video generator LT 443D or LT
4400 to configure a system.
2.2 Features
• I/O Connectors
The LT 4441/4442 is equipped with 11 sets of I/O connectors (a single set consists of a
primary input connector, a backup input connector, and an output connector).
• High-Speed Switching through the Use of Electrical Switches
The LT 4441/4442 uses electrical switches for switching channels 4 to 11. It also uses
high-speed detection circuits for detecting errors. These enable the LT 4441/4442 to
switch to a backup signal with barely any disturbances shown on the screen when
problems such as interruptions occur in the primary signal.
• Time until Errors Are Detected
The delay for starting the error detection at power up can be set to FAST or SLOW
depending on the rise time of the system signal source that the LT 4441/4442 is
connected to.
• Input Signal Selection
You can select the type of input signal for each channel from SDI (only for channels 1 to
3), NTSC/PAL analog black burst, and tri-level sync signals. However, channels 9 and 10
are used exclusively for AES/EBU digital audio signals, and channel 11 is used
exclusively for word-clock signals.
• Error Detection
When a signal level error is detected, the LT 4441/4442 lights the error LED on the panel
as well as the panel LED that indicates the channel that is causing the problem. This
feature allows quick investigation of the problem.