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DTMB Modulator A Chinese Terrestrial TV Standard, Model:Alto-GAF
 Main Feature   
Compliant with Terrestrial TV standard in China GB20600-2006
          1 2 TS ASI inputs for 188/204 byte, Packet Mode and Burst Mode
       1 TDS-OFDM modulation
          1 Support 1 or 3780 sub carriers
          1 Guard Interval: 1/4, 1/7,1/9
          1 FEC BCH LDPC: 0.4, 0.6, 0.8
       1 Time Inter-leaver Depth: 240,720
       1 Constellation: QPSK, 16QAM, 64QAM,4QAM-NR,32QAM
          1 Support SFN and MFN with SIP Processing
          1 Channel Bandwidth: 6,7,8MHz
       1 RF agile for VHF or UHF with step 1Hz
          1 RF Level from –10dBm to 0dBm
          1 MER>38dB, Shoulder>50dB
          1 External 1pps and 10MHz Clock inputs
          1 Linear and non linear pre correction
          1 RS232 Control and Supervision or IP Web browser in option
Technical Specification

TS Input:
 1 Complaint with EN 50083 ASI interface standard
 1 2 1ASI input 188/204 packet, Packet and Burst mode
 1 Bit Rate adaptation, Null Packet Filtering, PID Processing
 1 Connector type: BNC female, Impedance 75Ohm

Modulation and channel coding:
 1 TDS-COFDM Modulation
 1 Sub carriers: 1 or 3780
 1 FEC BCH LDPC: 0.4, 0.6, 0.8
 1 Guard Interval: 1/4,1/7, 1/9
 1 Time Inter-leaver Depth: 240,720
 1 Constellation: QPSK, 16QAM, 64QAM,4QAM-NR, 32QAM
 1 Channel Bandwidth: 6MHz, 7MHz,8MHz

Test Signal Modes:
 1 PRBS TS Sequence, PN 9,15,23
 1 Signal Carrier Test Tone
 1 SFN Fine Tune

Linear Pre-correction:
 1 Spectrum tilt adjustment: +/-2dB, step=0.2dB
 1 Useful Bandwidth: 7.61MHz
 1 Number of Pre correction points: 32
 1 Amplitude pre correction: +/-3dB
 1 Group Delay pre correction: +/-500ns

RF Output:
 1 Central frequency: VHF or UHF by 1Hz
 1 Signal level(Main): 0dBm +/- 2dB with 0dB to 10dB attenuation adjustable by 1dB step
 1 Signal stability: +/- 0.1dB
 1 Modulation error ratio(MER): >38dB
 1 Shoulder: >50dB @ +/-5MHz from central frequency
 1 Spurious: 50dB relative to total power
 1 Return loss: >15dB
 1 Connector type: N female, Impedance 50 Ohm

DTMB Network:
 1 SFN: Time offset setting
 1 MFN: BR adaptation, Static delay
 1 Loss of Reference Signal 1pps, 10MHz management
 1 SIP option field processing: TX ID, Time offset, Frequency offset, Power, Cell ID, TX Mute

Clock Reference:
Internal 10MHz

 1 Stability: 0.5ppm(typ); 3.0ppm(full temperature range)
 1 Aging: 0.8ppm; Output level: 0dBm +/- 3dB
External 10MHz
 1 Input level: -5dBm to +10dBm
 1 Input connector type: N female, 50 Ohm
External 1pps reference
 1 Input level: TTL level 5 KOhms; Pulse width: 1us
 1 Input connector type: BNC female

Control Mode:
 1 Local control: 6 buttons, LCD screen, LED
 1 Remote control: RS232 or WEB browser through IP Ethernet RJ-45 in option

Control and Alarm:
 1 Local control: 6 buttons, LCD screen, LED
 1 Remote control: IP Ethernet RJ-45 or RS232
 1 DB-9 with 2 Contact Relays for alarms: TS Loss, Bit rate Overflow, 1pps or 10MHz loss, SFN loss, etc

Physical conditions:
 1 Power supply:AC 220V+/-10%, 80W
 1 Operating temperature: 0-50℃
 1 Storage conditions:-10-70℃, humidity 10%-80% at 50℃
 1 Dimension: L=540mm, W=483mm, H=44mm (1RU)
 1 Weight: Net 7 kg, Gross 10 kg

Non linear Pre-correction: Single shoulder and double


Nb point

Abscissa range

Ordinate range




-12 dB to +12dB

-6dB to +6dB




-12 dB to +12dB

-25°to +25°



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