Leader LT 444 User manual

LT 4440 / LT 444
CHANGEOVER
INSTRUCTION MANUAL

TABLE OF CONTENTS
1. INTRODUCTION.......................................................................................................... 1
1.1 Scope of Warranty..............................................................................................................1
1.2 Operating Precautions .......................................................................................................1
1.2.1 Line Voltage and Fuse ................................................................................................1
1.2.2 Maximum Allowable Input Voltage .............................................................................. 2
1.2.3 Shorting of and Applying External Signals to Output Connectors...............................2
1.2.4 Installation...................................................................................................................2
1.2.5 Mechanical Shock.......................................................................................................2
1.2.6 Calibration...................................................................................................................3
1.2.7 Routine Maintenance ..................................................................................................3
1.2.8 Warm-Up.....................................................................................................................3
1.2.9 EU WEEE Directive ....................................................................................................3
1.3 Preventing Power Cord Disconnection ..............................................................................3
1.4 Rack Mounting Precautions ...............................................................................................4
2. SPECIFICATIONS ....................................................................................................... 5
2.1 Description .........................................................................................................................5
2.2 Features ............................................................................................................................. 5
2.3 Specifications .....................................................................................................................6
2.3.1 Inputs ..........................................................................................................................6
2.3.2 Outputs .......................................................................................................................6
2.3.3 Input/Output Characteristics (CH1 to CH11) ...............................................................6
2.3.4 Delay for Starting the Monitor .....................................................................................6
2.3.5 Input Signal Type ........................................................................................................6
2.3.6 Determination Criteria of the Signal Level ..................................................................7
2.3.7 Detection Reference Level..........................................................................................7
2.3.8 Error Display ...............................................................................................................8
2.3.9 Panel Key Lock ...........................................................................................................8
2.3.10 External Control (REMOTE) Connector......................................................................8
2.3.11 General Specifications ................................................................................................8
3. PANEL AND DIPSWITCH DESCRIPTION................................................................... 9
3.1 Front Panel....................................................................................................................... 11
3.2 Rear Panel ....................................................................................................................... 11
3.3 Side Panel........................................................................................................................12
3.4 Dipswitch Section.............................................................................................................12
3.5 Detailed Description of the Front Panel ...........................................................................13
3.6 Detailed Description of the Dipswitch Section..................................................................14
4. OPERATING PROCEDURE ...................................................................................... 16
4.1 Signal Inputs and Outputs................................................................................................16
4.2 Turning the Dipswitches ON/OFF ....................................................................................16
4.3 Setting the Error Detection Signal....................................................................................17
4.4 Setting the Error Detection Level .....................................................................................18
4.4.1 Low Level Setting......................................................................................................18

4.4.2 High Level Setting.....................................................................................................18
4.4.3 Example of Incorrect Level Setting ...........................................................................18
4.5 USER Settings .................................................................................................................19
4.5.1 USER Setting Example.............................................................................................19
4.6 Attenuator Function..........................................................................................................20
4.7 Powering Up.....................................................................................................................20
4.8 Powering Down ................................................................................................................20
4.9 Key Lock Function............................................................................................................21
4.10 Output Signal Switching ...................................................................................................21
4.11 Error Signal Release Operation .......................................................................................22
4.12 Auto Switching Function...................................................................................................23
4.12.1 When set to NORMAL and AUTO SWITCHING SWITCH FAULT ............................23
4.12.2 When set to NORMAL and AUTO SWITCHING DISABLED ....................................24
4.12.3 When set to OVERRIDE and AUTO SWITCHING SWITCH FAULT.........................24
4.12.4 When set to OVERRIDE and AUTO SWITCHING DISABLED .................................24
4.13 LIST OF OPERATING STATUS .......................................................................................25
5. REMOTE CONTROL ................................................................................................. 26
6. APPLICATIONS ......................................................................................................... 28
6.1 Connection .......................................................................................................................28
6.2 Dipswitch Setup Procedure..............................................................................................29
6.3 Panel Setup......................................................................................................................30
7. FACTORY DEFAULT SETTINGS............................................................................... 31
8. PREVENTING POWER CORD DESCRIPTION ........................................................ 32
8.1 Connecting the Power Cord .............................................................................................32
8.2 Disconnecting the Power Cord......................................................................................... 33
9. MAINTENANCE ......................................................................................................... 34

I
GENERAL SAFETY SUMMARY
■To Avoid Personal Injury
It is recommended that only qualified personnel with technical knowledge use this instrument
only after reading and fully understanding all functions of the instrument described in this
instruction manual.
This instrument is not designed and manufactured for consumers.
If you do not have enough knowledge on electricity, to avoid personal injury and prevent
damage to this product, please be sure to use this product only under the supervision of an
engineer who has sufficient knowledge about electronics.
■Precautions on Contents
Should you find the contents in this manual and any of its technical terms confusing, please
feel free to contact your local Leader agent.
■Symbols and Terms
Following terms and symbols that indicate necessary warnings and cautions used in this
manual and on the product are there for safe operation.
<Symbol>
The sections where this symbol is marked in this manual or instrument,
if not correctly performed or practiced, could result in personal injury or
cause danger to the instrument. Misuse could also produce
unintentional movement to create an operational impediment on the
instrument or other products that might be connected to it. Be sure to
refer to the safety precautions in this manual to safely use the part of
the instrument where this symbol is marked.
<Term>
Warning statements identify warning conditions that if disregarded or
not correctly performed or adhere to, could result in serious personal
injury or even loss of life.
<Term>
Caution statements identify warning conditions if disregarded or not
correctly performed or adhere to, could result in personal injury or
damage to the instrument.

II
GENERAL SAFETY SUMMARY
Review the following safety precautions to avoid operator’s injury and loss of life and prevent
damage and deterioration to this product. To avoid potential hazards, use this product as
specified.
■Warning on the Cases and Panels of the Instrument
Operator should not remove any cases or panel for any reasons. If you touch the inside of
the instrument it could result in electric shock or fire.
Refrain from spilling any liquid on or inserting flammable or metal objects inside the
instrument. Such actions could cause fire, electric shock, malfunction, and accidents
when the power is turned on.
■Warnings on Power Line
Make sure to connect only to the rated power line voltage. Excessive voltage may cause
fire.
Confirm the voltage of the commercial power line before connecting the power cord.
The power frequency of the power line should be 50/60 Hz.
Use only the power cord that came with the instrument. The use of other cords could
cause a fire hazard. If the provided cord is damaged, stop using it and contact your local
Leader agent.
The use of a damaged cord can cause electric shock or fire. When unplugging the power
cord, pull by the plug, not the cord.
The instrument does not have a power switch. Provide means for immediately shutting
down the power supply in an emergency.

III
GENERAL SAFETY SUMMARY
■Warnings on Installation Environments
●About the Operating Temperature Range
Operate the instrument in the temperature range of 0 to 45 °C. Operating the
instrument at higher temperatures could cause a fire hazard.
Rapid changes in the temperature from a cold environment to a warm environment can
cause condensation inside the instrument and could damage the instrument. If there is
a possibility of condensation, allow the instrument to sit for 30 minutes without the
power on.
●About the Operating Humidity Range
Operate the instrument in the humidity range ≤90 %RH (without condensation).
Do not operate the instrument with wet hands. Doing so could cause a shock or fire
hazard.
●About the Operation in the Presence of Gasses
Operating the instrument in or near the presence or storage locations of flammable or
explosive gasses or fumes could cause an explosion or fire hazard. Do not operate the
instrument anywhere near such environments.
●Do Not Insert Objects
Do not insert metal or flammable objects into the instrument or drop liquid on or into the
instrument. Doing so could cause fire, electric shock, malfunction, and accidents.
■Warning While Operating
If abnormal symptoms such as smoke, flame, or odor arise from the instrument while in
use, stop using the instrument immediately to avoid a fire hazard. Turn off the power and
remove the power cord plug from the outlet. Check that the fire has not spread, and
contact your local Leader agent.
■Warnings on Grounding
The instrument has a ground terminal to prevent electric shock and to protect the
instrument. Ensure that the instrument is properly grounded for safe operation.

IV
GENERAL SAFETY SUMMARY
Adhere to the warnings and precautions described above and use the instrument correctly and
safely. In addition, individual precautions are given in the sections of the instruction manual.
If you have any questions or comments regarding the contents of this instruction manual, please
contact your local Leader agent.
■Caution on Input/Output Connectors
Input connectors are rated with a maximum input.
Do not supply input exceeding the specifications given in this manual.
Also, do not supply external power to output connectors as it could cause the instrument
to malfunction.
■Caution on Extended Non-Use
Be sure to disconnect the power cord plug from the socket if you do not plan to use the
instrument for a long time.

1. INTRODUCTION
1
1. INTRODUCTION
Thank you for purchasing Leader’s measuring instruments.
Read this instruction manual thoroughly before using the product to ensure safe and correct
operation.
If you have any difficulties or questions on how to use the instrument after you have read
this manual, please feel free to contact your local Leader agent.
After you have read the manual, keep the manual in a safe place for quick reference.
1.1 Scope of Warranty
This Leader instrument has been manufactured under the strictest quality control
guidelines. Leader will repair free of charge any malfunctions that may occur under
normal use for 1 year after the date of purchase.
Keep the receipt or invoice as it will serve as a warranty card.
Even during the warranty period, Leader will charge a fee for repairs in the following
cases.
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.
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 Line Voltage and Fuse
Confirm that the power line voltage is correct before connecting the power cord.
The voltage range is indicated on the rear panel.
The instrument must be connected to the rated line voltage and line frequency of 50/60
Hz.
If the fuse blows, contact your local LEADER agent.
(The fuse is located in the power supply circuit inside the case.)

1. INTRODUCTION
2
1.2.2 Maximum Allowable Input Voltage
The maximum allowable input voltage to the input connectors is shown in the table
below. Do not apply excessive voltage to prevent damage to the instrument.
Table 1-1 Maximum allowable input voltage
Connector Maximum Allowable Input Voltage
Input connector ±5V (DC + peak AC)
1.2.3 Shorting of and Applying External Signals to Output Connectors
●Shorting of output connectors
Do not short the output connectors. Doing so can damage the instrument.
●Applying external signal to output connectors
Do not apply external signals to the output connectors. Doing so can damage the
instrument or device connected to it.
1.2.4 Installation
Do not use the instrument in the following environments.
●High temperature environments
Do not place the instrument under direct sunlight or near a heater (e.g., stove).
Avoid using the instrument in a way that leads to drastic changes in temperature
such as moving the instrument from a cold environment to a hot environment; this
may cause condensation.
Operating temperature range: 0 to 45°C
●High humidity environments
Do not place the instrument in a high humidity environment (e.g., bathroom, near a
humidifier).
Operating humidity range: ≤90% RH
●Dusty environments
1.2.5 Mechanical Shock
The instrument uses precision parts. If a strong shock is applied to the instrument such
as dropping the instrument, damage may result.

1. INTRODUCTION
3
1.2.6 Calibration
This instrument is produced under the strictest quality controls at the factory, but
accuracy may gradually deteriorate due to worn components.
Therefore, periodic calibration should be performed.
When service or calibration is required, contact your local Leader agent.
1.2.7 Routine Maintenance
Remove the power cord plug from the socket when cleaning the instrument.
Avoid the use of thinner or benzene solvents for cleaning cases, panels and knobs
since this might remove the paint or damage plastic surfaces.
Wipe cases, panels, and knobs lightly with a soft cloth damped with neutral detergent.
Do not allow water, detergent, or other foreign objects to enter the instrument while
cleaning.
If a liquid or metal object enters the instrument, it can cause electric shock or fire.
1.2.8 Warm-Up
To secure the most accurate operation, turn on the power to the instrument 30 minutes
before actual use to stabilize the internal temperature.
1.2.9 EU WEEE Directive
The EU WEEE Directive applies to this product and its accessories. When disposing of
this product or its accessories, follow the regulations in your country or region.
(WEEE Directive: Waste Electrical and Electronic Equipment)
1.3 Preventing Power Cord Disconnection
The instrument does not have a power switch. Provide means for immediately shutting
down the power supply in an emergency.

1. INTRODUCTION
4
1.4 Rack Mounting Precautions
The size of the instrument is 1U. When rack mounting the instrument, use the rack
support that came with the instrument as well as L angles, shelf boards, and slide rails
that are sold commercially. Be sure to follow the installation conditions and prevent
adverse effects on the instrument. (The table below lists the recommended slide rails.)
Leader will not be held responsible for accidents that occur when these rails are not
used.
Table 1-2 Recommended Slide Rails for the LT 4440/LT 444 (one rail on each side)
Parts Number Maker Name
C-203-16 IDEAL
KC-251-16 TAKIGEN
MODEL203-16 Accuride Japan
* Please also have eight M4 screws ready for attaching the slide rails.
If you have any questions about the slide rails indicated above or any questions about
rack mounting, contact your local Leader agent.
Figure 1-1 Attachment of the slide rail
* The method for fixing the slide rail (outer member) to the rack varies depending on the rack that you are
using. Please refer to the manual or specifications of the rack.

2. SPECIFICATIONS
5
2. SPECIFICATIONS
2.1 Description
The LT 4440/LT 444 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 4440/LT 444,
and the LT 4440/LT 444 detects errors on the amplitude of the primary input signal. A
single LT 4440/LT 444 provides 11 channels. HD-SDI (channels 1 to 6 only), SD-SDI,
AES/EBU digital audio, analog black burst signal, and tri-level sync signals are supported
through the configuration of the internal switch. If a switch occurs from the primary signal
to the backup signal, the LT 4440/LT 444 indicates the channel that caused the problem
on the panel LED.
The LT 4440 is a short version of the LT 444 with a depth of 400 mm. You can set up a
backup system by combining the LT 4440 with the LT 443D or the LT 4400 Multiformat
Video Generator.
2.2 Features
●Input/Output
Provides 11 channels (a single channel consists of PRIMARY input, BACKUP input,
and OUTPUT output) on a single LT 4440/LT 444.
●Delay for Starting the Monitor
The delay for starting the error monitor at power up can be set to FAST or SLOW
depending on the rise time of the system signal source being connected.
●Determination Criteria of the Signal Level
The internal preset switch allows level detection switching among SD-SDI, AES/EBU
digital audio, NTSC or PAL analog black burst, HD analog tri-level sync, HD-SDI
(only supported on channels 1 to 6), and other signals.
●Error Display
When a signal level error is detected, the LT 4440/LT 444 illuminates the error LED
on the panel as well as the panel LED that indicates the channel causing the
problem. This feature allows quick investigation of the problem.
●System Configuration
Because the LT 4440 has the same depth as the LT 4400, you can configure a 2U
backup system by combining the LT4440 with the LT4400.

2. SPECIFICATIONS
6
2.3 Specifications
2.3.1 Inputs
PRIMARY inputs 1 input each for 11 channels
(75ΩBNC connector)
BACKUP inputs 1 input each for 11 channels
(75ΩBNC connector)
2.3.2 Outputs
OUTPUT outputs 1 output each for 11 channels
(75ΩBNC connector)
2.3.3 Input/Output Characteristics (CH1 to CH11)
Return Loss 30 dB (0 to 10 MHz)
15 dB (10 to 750 MHz)
10 dB (750 MHz to 1.5 GHz)
Insertion Loss 0.2 dB (0 to 10 MHz)
0.5 dB (10 to 200 MHz)
2.0 dB (200 MHz to 1.5 GHz)
Cross Talk –60 dB (0 to 10 MHz)
–30 dB (10 MHz to 1.0 GHz)
–20 dB (1.0 to 1.5 GHz)
2.3.4 Delay for Starting the Monitor
Select from two delay settings for starting the error monitor at power up according to
the rise time of the system signal source connected to the LT 4440/LT 444.
FAST 1 minute or more (60 to 80 s)
SLOW 4 minutes or more (240 to 320 s)
2.3.5 Input Signal Type
Set the type of input signal applied to the LT 4440/LT 444 using the internal dipswitch.
Signal Type HD-SDI (CH1 to CH6 only)
SD-SDI (270 Mb/s)
SD-SDI (143 Mb/s)
AES/EBU digital audio
Tri-level sync signal
NTSC black burst
PAL black burst

2. SPECIFICATIONS
7
2.3.6 Determination Criteria of the Signal Level
Detection Level Detects an error when the amplitude of the
input signal drops by 2 to 5 dB from the
defined level and makes the switch. The
detection level varies slightly depending on
the type of signal specified using the
internal dipswitch. The detection level can
be set to LOW or HIGH for each signal
type.
2.3.7 Detection Reference Level
When the Determination Criteria Is Set to Low (*1)
HD-SDI (CH1 to CH6 only) 450 to 635 mV (800 mV)
SD-SDI (270 Mb/s) 450 to 635 mV (800 mV)
SD-SDI (143 Mb/s) 450 to 635 mV (800 mV)
AES/EBU digital audio 631 to 794 mV (1000 mV)
NTSC black burst -180 to -227 mV (-286 mV)
PAL black burst -190 to -238 mV (-300 mV)
Tri-level sync 337 to 476 mV (600 mV)
When the Determination Criteria Is Set to HIGH (*1)
HD-SDI (CH1 to CH6 only) 505 to 713 mV (800 mV)
SD-SDI (270 Mb/s) 505 to 713 mV (800 mV)
SD-SDI (143 Mb/s) 505 to 713 mV (800 mV)
AES/EBU digital audio 734 to 924 mV (1000 mV)
NTSC black burst -210 to -264 mV (-286 mV)
PAL black burst -220 to -277 mV (-300 mV)
Tri-level sync 379 to 535 mV (600 mV)
User-Defined Detection Level Setting (CH7 to CH11 only)
USER setting 1 Set between -100 to -700 mV (*2)
USER setting 2 Set between -100 to -700 mV (*2)
Expansion of the Detection Level Using the Attenuator (CH7 to CH11 only)
Set the internal attenuator to expand the detection level further by 5 times
USER setting 1 Set between -700 to -3500 mV (*2)
USER setting 2 Set between -700 to -3500 mV (*2)
*1 The signals levels inside the parentheses are those during normal conditions.
User-Defined Detection Level Setting (CH7 to CH11 only)
*2 When a signal equivalent to the H.SYNC waveform is applied. The specifications of the detection
level may not be achieved depending on the waveform shape.

2. SPECIFICATIONS
8
2.3.8 Error Display
Total Error LED Notifies errors by illuminating the error LED
on the panel.
Error Channel LED Detects the channel causing the error and
notifies the channel by illuminating the
corresponding LED.
2.3.9 Panel Key Lock
Time to Key Lock The key lock is automatically enabled when
key operation is not detected for 60 s.
2.3.10 External Control (REMOTE) Connector
Application For external remote control.
Inputs RESET, AUTO SWITCHING, and TOGGLE
SYNC
Outputs FAULT and SYNC SOURCE
Connector Type 9-pin Dsub connector (female)
(Inch screws for fixing the shell)
2.3.11 General Specifications
Environmental Conditions
Operating Temperature 0 to 45°C
Operating Humidity ≤90% RH (without condensation)
Spec-Guaranteed Temperature 5 to 40°C
Spec-Guaranteed Humidity ≤85% RH (without condensation)
Operating Environment Indoor use
Operating Altitude Up to 2,000 m
Overvoltage Category II
Pollution Degree 2
Power Requirements
Voltage 90 to 250 VAC (no switching necessary)
Frequency 50/60 Hz
Power Consumption 25 Wmax.
Dimensions 426(W) × 44(H) × 400(D) mm (LT 4440)
426(W) × 44(H) × 560(D) mm (LT 444)
(excluding protrusions)
Weight 3.5 kg (LT 4440)
4.0 kg (LT 444)
Accessories Rack supports ................................. 2
Rack support attachment screws .... 4
Power cord ...................................... 1
Instruction manual........................... 1
Cover/Inlet stopper.......................... 1

3. PANEL AND DIPSWITCH DESCRIPTION
9
3. PANEL AND DIPSWITCH DESCRIPTION
The front panel, rear panel, side panel, and dipswitch section of the LT 4440/LT 444 are
indicated below.
Figure 3-1 Front Panel
Figure 3-2 Rear Panel
Figure 3-3 Side Panel

3. PANEL AND DIPSWITCH DESCRIPTION
10
Removing the four screws from this cover enables you to set the internal dipswitch.
This figure shows the factory default settings.
Figure 3-4 Dipswitch Section

3. PANEL AND DIPSWITCH DESCRIPTION
11
3.1 Front Panel
Figure 3-1 shows the front panel of the LT 4440/LT 444.
1 KEY LOCK
Switch used to turn ON/OFF the key lock.
This key is also disabled while the instrument is starting up at power up.
2 FAULT INDICATOR
This LED blinks when a level error is detected.
This LED keeps blinking even if the error is cleared.
The LED is cleared by clearing the error and pressing the RESET key.
3 AUTO SWITCHING
Switch used to set the operation mode to SWITCH FAULT or DISABLED when an
error is detected.
4 SYNC SOURCE
Switch used to manually switch the signal passed to OUTPUT between PRIMARY
and BACKUP input.
5 FAULT CHANNEL
The LED of the channel on which a level error was detected keeps illuminating.
This LED keeps illuminating even if the error is cleared.
The LED is cleared by clearing the error and pressing the RESET key.
3.2 Rear Panel
Figure 3-2 shows the rear panel of the LT 4440/LT 444.
6 REMOTE
Connector for remote control. It also has a level error status output.
7 PRIMARY/BACKUP/OUTPUT
OUTPUT connector that passes the signal from the PRIMARY or BACKUP signal
connector.
8 AC inlet
Connect the power cord that came with the instrument. The operating supply voltage
range is 90 VAC to 250 VAC.
A fuse socket is under the AC inlet.

3. PANEL AND DIPSWITCH DESCRIPTION
12
3.3 Side Panel
Figure 3-3 shows the side panel of the LT 4440/LT 444.
9 Serial Number
Provide this number when contacting LEADER.
3.4 Dipswitch Section
Figure 3-4 shows the dipswitch section of the LT 4440/LT 444.
10 Dipswitch cover
Removing the four screws from this cover enables you to set the internal dipswitch.
11 Signal selection switches CH1 to CH11
Dipswitches used to select the signal type for CH1 to CH11.
12 Error detection level selection switch
Switch used to set the error detection sensitivity to high level or low level for each
signal type selected.
13 Mode selection switch
Switch used to set the operation mode.
14 User defined volume
Adjust the USER ADJUST1 and USER ADJUST2 dials to adjust the error detection
levels.

3. PANEL AND DIPSWITCH DESCRIPTION
13
3.5 Detailed Description of the Front Panel
Table 3-1 Front panel functions
No. Key Name LED Name Description
KEY LOCK ON/OFF switch.
ON Illuminates when KEY LOCK is ON.
1 KEY LOCK
OFF Illuminates when KEY LOCK is OFF.
Use this key to clear the PRIMARY or BACKUP LED under
FAULT INDICATOR.
(Valid only when KEY LOCK is OFF.)
PRIMARY This LED keeps blinking when a level error is detected when
SYNC SOURCE is set to PRIMARY.
2 FAULT
INDICATOR
(RESET)
BACKUP This LED keeps blinking when a level error is detected when
SYNC SOURCE is set to BACKUP.
Switch used to set the operation mode to SWITCH FAULT or
DISABLED.
(Valid only when KEY LOCK is OFF.)
SWITCH
FAULT
When a level error is detected in the signal being passed to
OUTPUT, a switch is made to the other signal
(PRIMARY/BACKUP).
3 AUTO
SWITCHING
DISABLED Auto switching is not performed even when a level error is
detected in the signal being passed OUTPUT
Switch used to manually switch the signal passed to OUTPUT
between PRIMARY and BACKUP input.
(Valid only when KEY LOCK is OFF.)
PRIMARY Indicates that the PRIMARY input signal is currently being
passed to OUTPUT. Common to CH1 to CH11.
4 SYNC
SOURCE
BACKUP Indicates that the BACKUP input signal is currently being passed
to OUTPUT. Common to CH1 to CH11.
When the FAULT INDICATOR illuminates due to a level error,
the corresponding channel LED illuminates.
5 FAULT
CHANNEL
1～11 The LED of the channel on which a level error was detected
illuminates. You can clear the LED using the FAULT INDICATOR
key.
(Clearing is valid only when KEY LOCK is OFF.)