Leitch distribution amplifiers

By Arseny Voroshilov

Review contents:

Routing and Distribution Equipment Auxiliary routing units of “Profitt” Company Multipurpose modules of Synapse system New line of distribution amplifiers from Extron Electronics Auxiliary routing and distribution equipment Kramer Electronics Leitch distribution amplifiers Devices of Marshall Electronics Company Routing and distributive equipment of Netrwork Electronics Company New HDTV Patch panels from Oxygen DCT IQ series modules from Snell & Wilcox Redbox series audio distribution equipment of from Sonifex Company Modular units from Thomson Broadcast and Multimedia Solutions The distribution equipment of Vistek Company

Leitch Company lets out a wide assortment of products and systems which are successfully applied in sphere of TV production and broadcasting. The Leitch name became some symbol of quality as units of the company differ not only by functionality, but high quality and reliability as well. Therefore not occasionally the Proline company, realizing own projects, very often chooses and offers to customer the equipment of Leitch Company.

The large part of this company assortment is occupied with the products intended for signal distribution, in particular, these are the distribution amplifiers included as a part of modular system 6800+. The line of modules of distribution amplifiers provides their application in sphere of TV production and broadcasting, and also in the telecommunication area. Application of high-quality components in combination with high assembling density has allowed to achieve enough high level of product quality and wide functionality under compact sizes, that in modern TV is important advantage.

Line of Leitch distribution amplifiers includes both digital and analog units.

Digital distribution amplifiers

HSE6800+ and HSD6800+

These are new units of 6800+ family, operating with consecutive digital signal of video. Module HSD6800+ is the distribution amplifier of SD/HD/ASI signals with function of correction of signal depending on cable length, and HSE6800+ in addition is also provided with reclocking function.

HSD6800+ (above) and HSE6800+ modules

For these devices a high quality of signal, an opportunity of remote control and diagnostics, carried out by means of control system Leitch are distinctive features. It means, that installation of parameters of modules, its control and monitoring can be realized either locally by means of crosspieces on the board, or remotely by computer with corresponding software. Communication of system 6800+ with computer can be realized over RS-232 interface or over Ethernet. In the latter case an installation of ICE6800+ module is required.

Both of the module are provided by single input and can have eight (double back panel of sockets) or four (single back panel of sockets) ASI-compatible outputs. On input the automatic detecting of signal presence and automatic correction of losses in cable are carried out. There is a mode of notification about errors and an opportunity of manual/automatic reclocking under speeds 143, 177, 270, 360, 540 Mbit/s and 1.485 Gbit/s (only for HSE6800+). The report on reclocking condition is also formed only for HSE6800+ in which function of automatic or compulsory bypass is also inherent.

HSD6800+/HSE6800+ modules block diagram

The basic features of HSD6800+/HSE6800+ modules are as follows:

• Type of input signal: HD, SD, ASI (socket BNC, 75 Ohm);
• Return losses — not less than 18 dB in bandwidth of 5 MHz… 1.5 GHz;
• Maximum signal level — not less than 0.88 V;
• Correction of losses in cable: for SD/270 Mbit/s — 0…300 m; for HD — 0…100 m. Cable is Belden 1694A or equivalent;
• Outputs: HD, SD — 8; ASI — 4 (socket BNC, 75 Ohm);
• Type of signal: HD, SD, ASI;
• Amplitude of signal — 800 mV ±10%;
• Two modifications of each module are produced (see table).

Assortment of modules HSD6800+/HSE6800+
Modification	Description
HSD6800+D	Distribution amplifier HD, ASI and SDI with correction of losses in cable. Dual panel of sockets for cabinets FR6802+X (F)
HSD6800+S	Distribution amplifier HD, ASI and SDI with correction of losses in cable. Single panel of sockets for cabinets FR6802+X (F)
HSE6800+D	Distribution amplifier HD, ASI and SDI with correction of losses in cable and with reclocking. Dual panel of sockets for cabinets FR6802+X (F)
HSE6800+S	Distribution amplifier HD, ASI and SDI with correction of losses in cable and with reclocking. Single panel of sockets for cabinets FR6802+X (F)

VSM6800+

This distribution amplifier with monitor output combines functions of correction of losses in cable, reclocking and converter of digital signal 4:2:2 to analog composite NTSC/PAL. In case of installation of dual output module for cabinet FR-6802+ the module has one input SDI, four analog composite outputs and four outputs SDI. If cabinet FR6802+XF and single output module are applied the output number of each type is reduced down to two. The module is completely compatible with SMPTE 259M-C standard. It is possible to choose the standard of signal NTSC/PAL-B/PAL-M for analog output.

Control of the module can be carried out locally or remotely by means of software Pilot Lite (standard delivery), Pilot b Navigator (the option, demands presence ICE6800+) or by control system of the third software producers according with Leitch CCS Protocol. On boards are established the light-emitting diodes reflecting the unit status and chosen modes.

There are three versions of VSM6800+ module complete set:

• VSM6800+ — distribution amplifier board (for cabinets FR6802+DM (F));
• VSM6800+S — module board in complete set with single panel of sockets (for cabinets FR6802+X (F));
• VSM6800+D — module board in the complete set with dual panel of sockets (for cabinets FR6802+X (F)).

VSM6800+ block diagram

USM-6800

USM-6800 is universal coder/distribution amplifier/DAC. It is provided by coder NTSC/PAL on four outputs, supplementing it as distribution amplifier SDI with four outputs. The module allows to remove jitter from 4:2:2 signal before stage of coding and conversion to analog signal. Automatic recognition of line number (525 or 625) in input signal is provided also.

In addition to composite analog outputs the USM-6800 it is possible to configure by such way that to receive outputs of component signal RGB, YUV or Y/C. If RGB or YUV have chosen, three output sockets BNC provide delivery of component signal, and remained one output remains composite. If version Y/C is selected it is provided with two sockets, and composite signal is delivered to others. For the concordance of the module with socket Y/C it is possible to use the additional adapter — an adapter from BNC to Y/C. The signal on all four outputs SDI is present always.

USM-6800 block diagram

VTM6800+

This module the amplifier represents triple distributor SDI with outputs of composite signal to monitors. It has three independent SDI inputs, for each of which SDI outputs and composite signal with correction and reclocking are provided. The module corresponds to SMPTE 259M-C standard. The user has opportunity to choose mode NTSC/PAL-B. For each of channels the amplification adjustment (Gain) is provided. For coding of composite signal the 10-digit DAC and 8-digit signal path are applied. Besides each channel is provided with built-in GDC. Presence of signal in the channel is displayed by the light-emitting diode indicator.

VSD6800+/VSE6800+

VSD6800+ is classical distribution amplifier SDI with function of correction of losses in cable. It can control remotely. The module can operate with digital signals with speed 10…540 Mbit/s, distributing them on eight SDI outputs or four ASI outputs.

In many respects the unit VSE6800+ is similar to VSD6800+, but for it bottom limit of speed is equal to 143 Mbit/s, reclocking function is added too.

VSI6800+

Module VSI6800+ is the distribution amplifier of SDI/ASI signals with correction of losses in cable and reclocking function. It meets the requirements of SMPTE259ABC and DVB-ASI. The module is produced in two following versions:

• VSI6800+S — one input and four outputs;
• VSI6800+D — two inputs and eight outputs.

Adjustment of VSI6800+, it operation and monitoring are realized locally or remotely. Feature of the unit is application of transformers on input and output for duplication of signals; polarity of input and output signals is the same. If signal reclocking is not possible the mode of bypass which can be also activated compulsorily is automatically switched on.

VSI6800+ block diagram

Analog distribution amplifiers

VDA6800+

VDA6800+ is the general purpose unit and base model of analog distribution amplifier of Leitch line, differing by high efficiency, reliability and reasonable price. The module carries out amplification and distribution on some composite (NTSC, PAL, SECAM) and component outputs of video signals, subcarrier, and digital signals of audio AES (on coaxial interface) also.

VDA6800+ block diagram

Basic characteristics of VDA6800+:

• One differential input;
• Number of outputs: 4 with single panel of sockets and 8 — with dual panel;
• Range of amplification adjustment — ±3 dB;
• Bandwidth — more than 50 MHz;
• Opportunity of “hot” replacement of the module.

VEA6800+/VRG6800+/VCA6800+/VPD-6830

Unit VEA6800+ is differed from base VDA6800+ unit by availability of function of losses correction in cable and allows carrying out the correction for the communication line by 300 m length and more (cable Belden 8281 or other with similar parameters). Besides this distribution amplifier does not operate with audio signals.

Further point at the line is VRG6800+ unit. It is already more complex and functional device. VRG6800+ allows remotely operate by amplification and correction of losses in cable, and also to support constant level of synchrosignal on output. Due to high efficiency the module can be used for operation with analog composite and component (SD/HD) signals, videographic signals, and in some cases even for amplification and distribution of high-frequency and even of some digital signals.

VCA6800+ is analog distribution amplifier with functions of cable correction and fixing of level of composite signal NTSC and PAL for what it is provided two modes: soft and rigid. Additionally it is possible to establish the submodule of adjustment of amplification. On corresponding parameters it is similar to two previous units.

And, at last, the line of distribution amplifiers of video signals of 6800+ series is completed with module VPD-6830. Besides signal amplification and distribution, it provides correction of cable losses, signals level fixing and allows programming some functions. The module consists of board of distribution amplifier and a set of submodules. The base board can operate independently, carrying out amplification, distribution, correction and soft fixing of signal. Correction by means of means of base board only allows to compensate losses in cable Belden 8281 by length up to 300 m. The corrector is possible to adjust also for operation with other cables for what the corresponding submodules are applied.

VPD-6830 is provided by single differential input, eight outputs and operates at bandwidth of 30 MHz (-3 dB).

VRG6800+ block diagram

For base board the following submodules are provided:

• Extra EQ — provides additional correction of cable losses — up to 750 m. With its installation total length of cable line will be about 1000 m;
• Delay — provides realization of delay in the range of 38…1235 nanoseconds (1 ms). Combination of this submodule with VPD-6830 allows carrying out the correction, level fixing and signal delay;
• White Clip — provides soft and rigid restriction of white level adjusted by user;
• Dual EQ — it is used for the operation with cables Nokia 0.6/2.8 and other cable types.

Distribution amplifiers of audio signal

Besides devices for operation from video, Leitch company produces some distribution amplifiers of audio signal included into units of 6800+ series also. Their brief features is given in the table.

Distribution amplifiers of audio signal of 6800+ series
ARG6800+	The distribution amplifier of analog audio signal with remote adjustment of amplification. Protection of input against overvoltage (up to 120 V). Untransformator scheme, symmetric inputs/outputs (1 or 2 + 4 or 8 depending on modification). Maximum level of input/output signal — +28 dBu, a range of adjustment of amplification -95.5…+31.5 dB with step 0.5 dB, output impedance — 66 Ohm.
AES6800+B/+C	The distribution amplifier of digital audio signals AES/EBU. It is provided with one differential input and nine outputs: index +B — symmetric; index +C — asymmetrical (coaxial). It provides cable correction and reclocking (frequency of digitization 32…192 kHz).

Besides units of 6800+ series the Leitch Company produces distribution amplifiers of 680 and EX series. In comparison with 6800+ these units are more simple, but are also successfully applied in TV systems, basically for operation with composite video and analog audiosignals though there are some models and for operation with digital signals.

The material is provided by Proline Company