Screen SFT 251 V/M

Digital, Analog, and Dual Cast TV Transmitter FUTURE SFT Series is reaching the highest technology level in both TV Digital Signal Processing and RF domain.

This TV Transmitters Series reaches top performances thanks to:

1) ARK-X: the new evolution of the ARK Series multistandard DTV Drivers, the ARK-X Series, able to meet or exceed all the DTV International Broadcasters requirements.

The improvement of digital adaptive precorrection and configuration flexibility are the key points for this advanced product, developed by the excellent Screen R&D Digital Signalling dept.

ARK-X IS AVAILABLE IN DIFFERENT CONFIGURATIONS

2) Latest generation LDMOS devices: more rugged and efficient compared to the past, with a special low-loss design of matching and combining system, together with extremely high-efficiency power supplies (over 96% efficiency).

3) Compactness: a new concept of heatsync and ultracompact power supplies grants the minimum sizes of amplifier modules with air cooling or liquid cooling systems, and a greatly reduced dimensioning of the cooling system itself.

4) Easy and Fast maintenance: Screen Group’s 25 years’ experience allowed for designing this new FUTURE SFT SERIES with a significantly improved easy-maintenance concept.

All RF power modules are hot pluggable (both liquid and air cooled versions) for an easy bench testing and/or instant replacement on site.

All RF power modules are equipped with 3 independent power supplies for maximum redundancy and easy single phase or balanced three phases operation selection. These 3 power supplies are also hot pluggable themselves, for a unique way of smart maintenance.

The latest generation of industry higher class power supplies grants over 96% efficiency with wider input AC range capability and greater ruggedness.

5) Smart System Design: latest generation progressive RF combiner with ultracompact unbalancing dummy loads and a smart intercommunication interface between RF modules, drivers and Logical Control System allow for a very clean and easy to maintain system configuration both for liquid and air cooling equipment.

Benefits

TV Transmitters FUTURE SFT Series is the result of Screen’s R&D intense activity on High-Performance RF Amplifiers, combined with the new widely improved software precorrection capability and very efficient power supplies (>96%).

TV Transmitters FUTURE SFT Series features a built-in SFN adapter and very advanced SWDT® (Software Defined Transmitters) technology, that allows implementing different modulation patterns – either digital or analog (DVB, ATSC, ISDB-T, DTMB, DAB, DAB+,T-DMB, ATV, etc.) – in the same hardware.

Moreover, the SWDT® technology allows the selection of operation modes in various ways:
– remotely, using a clean contact;
– via SNMP commands;
– via TCP/IP, using the Web graphic interface;
– or even via a dedicated command inserted into the transport stream.

Functional interfaces are available for complete remote control of the transmitters by serial protocols or TCP/IP ports, thanks to the internal Web server or built-in SNMP.

Main Specifications

Frequency range:

VHF (Band III): 170 to 255 MHz, in 1 Hz step

Available standards (all standars are full compliant)

Digital TV and Analog TV

DVB-T, DVB-T2, DVB-H, ISDB-Tb, ATSC, ATSC Mobile DTV, DTMB, ATV

Power Supply

AC Line Voltage: 380 to 415 (3 phases), 208 to 240 Delta or Star; 47 Hz to 63 Hz (specify at order)

AC Line variations: +/- 15%

Power factor: ≥ 0,98

Environmental Conditions

Altitude: 2500 m above sea level (> 2500 m on request)

Operating temperature range: -10°C to +45°C at sea level, upper limit derated of 2 °C per 300m over 1000 m above sea level

Relative humidity: 95 %, not-condensing

Cooling method: Forced Air with external heat exchanger with redundant pump and fan

RF output

Output power range: See selection table 

RF load impedance: 50 Ohm

VSWR: Power reduction after exceeding the set value or switch off after three attempts

RF Output connector: See selection table

Transmitter size

Rack Unit, Weight, Dimensions: See selection table

Digital Modulation Performance

MER: up to 38 dB (typ. 36 dB)

Shoulders (@ FO 3.5 MHz ATSC) or (@ FO 4.3 MHz DVB) or (@ FO 3.3 MHz ISDB-T): up to -42 dB (typ. -39 dB)

Synchronization

Reference frequency: 10 MHz, 0.1 V to 5 V (Vpp) or TTL, BNC

Reference pulse: 1pps (1 Hz, TTL, BNC)

Operations Control and Monitoring

Remote:

Web based Interface

SNMP V1 V2 V3

Telnet access via ethernet

Local:

Extensive front panel control (color display, keypad)

Local terminal on RS232 or LAN

USB for upgrade

Compliance and Conformity

RoHS: 2011/65/EC

Radio Equipment Directive (RED): 2014/53/EU

Safety: EN 60215

EMC: EN 301-4891-1 - ETSI EN 302 296-2 V1.2.1 (2011-05)

FCC: Part 74

WEEE: 2012/19/EU

Manufacturing: ISO 9001:2015

Selection Table

Model: Screen SFT 251 V/M

Output band: VHF (III)

Working Class: AB

Dimensions: 1 x 22 RU

N. Amplifiers: 1

Amplifier Model: SFK 112 V/A

Output Connector: 1+5/8"

Cooling: Air

DVB, ISDB-T, DTMB W rms: 250

ATSC W rms: 300

Analog Peak Sync (W): 550

Shoulders (@ FO 4.3 MHz DVB) or (@ FO 3.3 MHz ISDB-T) or (@ FO 3.5 MHz ATSC): -39