The Leader LT4448 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. A single LT4448 has 11 BNC channels and 3 LTC channels. These channels can receive SDI,NTSC/PAL black burst, HD tri-level sync, AES/EBU digital audio, word-clock signals, and LTC signals. SDI signals are switched with relays; all other signals are switched with electronic switches. The LT4448 has redundant power supplies. Alarms are generated when errors occur.

The LT4448 is used in combination with the LT4610/LT4611 (SYNC GENERATOR) or the LT4600A(MULTIFORMAT VIDEO GENERATOR).

Input / Output
Provides 11 channels (a single channel consists of a primary input, a backup input, and an output) on a single LT4448.

Input Signal Switching
Relays are used to switch channels 1 and 2. Electronic switches are used to switch channels 3 to 11. In addition to the electronic switches, channels 3 to 11 are also equipped with high-speed, error detection circuits. The LT4448 provides 3 channels of LTC.

Input Signal Selection
Channel 1 and 2 inputs are dedicated inputs for SDI (3G/HD/SD), NTSC/PAL Black burst and Tri-Level Sync signals. Channel 3 to 8 inputs are dedicated inputs for NTSC/PAL Black burst and Tri-Level Sync signals. Channel 9 and 10 inputs are dedicated inputs for AES/EBU digital audio signals. Channel 11 input is a dedicated input for word-clock signals (TTL). For LTC signals, dedicated LTC inputs / outputs (2Vp-p,differencial input) are provided.

LTC Channel
There are 3 LTC channels. Each has 2 inputs (primary, backup) and 1 output. In addition, the LT4448 can be connected to the LT4610 (SYNC GENERATOR) with a dedicated cable (optional).

Fault detection
When an input signal level error is detected, the panel fault LED on the LT4448 illuminates as well as the panel LED that indicates the channel which is causing the problem. This feature allows for quick notification of the error. Channels 3 to 11 are equipped with highspeed fault detection circuits. When interruptions occur in the primary signal, these enable the LT4448 to switch to a backup signal with barely any noticeable disturbances showing on a monitor.

Power Supply Start Time
A delay for starting the fault detection at power up can be set to approximately 1 minute or approximately 4 minutes, depending on the rise time of the system signal source that the LT4448 is connected to.

SNMP Ready
Error monitoring over an Ethernet network is possible. Traps are issued for error detection, panel control, and remote control. In addition, the error details and DIP switch settings (except for the user defined fault detection level) can be read as status information. IP address configuration software is included. (Windows 8 , Windows 10)

Redundant Power Supply
Redundant power supply provides extra reliability. Alarms are generated when an error occurs.

Web Browser
The LT4448 can be controlled by a web browser.

Features:

• Provides 11 channels on a single unit.
• Relays are used to switch between the primary signals and backup signals of channels 1 and 2. High-speed electronic switches are used to switch between the primary signals and backup signals of channels 3 to 11. For LTC, switching is possible between primary signals and backup signals for three inputs.
• The input signal type can be selected. On channels 1 and 2, you can select SDI signals (3G, HD, SD), NTSC/PAL black burst signals, or HD3 tri-level sync signals. On channels 3 to 8, you can select NTSC/PAL black burst signals or HD3 tri-level sync signals. Channels 9 and 10 are exclusive to AES/EBU digital audio signals. Channel 11 is exclusive to word-clock signals (TTL input). LTC channels are exclusive to LTC signals (2 Vp-p differential input).
• LTC channels provide three systems of two inputs (primary and backup) and three systems of one output. In addition, an LTC cable (sold separately) can be used to connect to a LT 4610 (Sync Generator).
• A delay for starting the fault detection at power up can be set to approximately 1 minute or approximately 4 minutes depending on the rise time of the system signal source that the LT 4448 is connected to.
• Redundant power supplies are available for increased reliability. Alarms are generated when errors occur.

Specifications:

• SDI Signal
• 3G-SDI: SMPTE ST 372, 424, 425
• HD-SDI (including HD dual link): SMPTE ST 274, 292, 296
• SD-SDI: SMPTE ST 125, 259
  
  Synchronization signal
• NTSC: black burst signal SMPTE ST 170, 318, 154
• PAL: Black Burst Signal ITU-R BT.1700, EBU N 14
• HD: ternary synchronization signal SMPTE ST 274, 296
• AES / EBU digital audio signal AES 3, SMPTE ST 276
• LTC signal: SMPTE 12M-1
  
  Input/Output terminal
• Primary input terminal: 1-10 ch 10 lines each 1 input (75 Ω BNC), 11 ch 1 line 1 input (TTL, 75 Ω BNC)
• Backup input terminal: 1-10 ch 10 lines each 1 input (75 Ω BNC), 11 ch 1 line 1 input (TTL, 75 Ω BNC connector)
• Output terminal: 1-10 ch 10 lines each 1 output (75 Ω BNC), 11 ch 1 system 1 output (+ 5V CMOS, 75 Ω BNC)
  
  LTC terminal
• Connector: D - SUB 25 pin (input and output shared)
• Number of inputs: 3 lines each 2 inputs (PRIMARY, BACKUP)
• Number of outputs: 3 lines 1 output (OUTPUT)
  
  Input signal
• Setting method: Dip switch or input signal type
• Select for each channel with external control (browser)
• 1-2 ch NTSC black burst signal
• PAL black burst signal
• HD trivalue sync signal
• SD-SDI signal (270 Mb/s)
• HD-SDI signal (1.485 Gb/s)
• 3G-SDI signal (2.97 Gb/s)
• 3-8 ch NTSC black burst signal
• PAL black burst signal
• HD trivalue sync signal
• 9, 10 ch AES / EBU digital audio signal
• 11 ch word clock signal (TTL)
• LTC LTC signal, GPIB signal (LT 4610 alarm output)
• (When input / output characteristics are not described)
  
  General
• Power supply: (duplexed)
• Voltage / power consumption: AC 90-250 V (50/60 Hz) / 25 Wmax
• Dimension (WxHxD): 16.77" x 1.73" x 15.74" (not including protruding portion)
• Weight: 8.8 lbs