TERRA TDX-311C (8PSK+QPSK CI receiver / DVB-T@COFDM modulator - for MMH-3000)

Code: R81711C
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Base Unit UC-380 (for Modular Headend MMH-3000)
View of the module
Base Unit UC-380 (for Modular Headend MMH-3000)
The included accessories
TDX-311C R81711C module has been designed for use in the MMH-3000 headend (in the Base Unit UC-380 R81700). This DVB-S/S2 (8PSK/QPSK) receiver / DVB-T (COFDM) modulator (also called as transmodulator) is used to receive encrypted or FTA channels. One device is sufficient for a whole transponder (even more than a dozen channels) which is converted into a DVB-T multiplex.
TDX-311C has CI slot which, in the case of encrypted channels, is used to connect a suitable conditional access module with dedicated smart card. Such card allows for decryption of the whole transponder.
It is worth to notice that the bandwidth of satellite transponders is usually greater than the capacity of DVB-T multiplexes. The maximum bitrate at the output of TDX-311C module is 31.66 Mbps. In practice, it translates into 7-8 channels of standard definition (SD) or 2-3 channels in high definition (HD). Selecting desired channels from a transponder, the user should include a 10%...15% safety margin due to changeable bitrate of the channels. When the desired channels from the transponder require more bandwidth, the MPEG-2 TS stream from the module can feed additional TDX-311C R81711C modules or DVB-T modulator/re-multiplexer TRX-360 R81709.
The channels received from a transponder can be selected according to the needs. The condition is just not to exceed the maximum bitrate at the modulator output. In order to save bandwidth, it is also possible to filter unused services (unnecessary audio tracks, teletext). The module, similarly to all components of TERRA headend, can be configured using free Terra Link or paid CMH Master R81706 software.
View of the main configuration window of TDX-311 R81711. The bitrate of the output multiplex takes 86% (27.51 Mb/s from 31.66 Mb/s) of the device capacity.
The window for selecting desired channels and eliminating unnecessary services
More on MMH-3000 headend you can read in the article :
Name TDX-311C
Code R81711C
RF input
Frequency range
950-2150 MHz
Input level / impedance 45-85 dBµV / 75 Ω
Modulations QPSK. 8PSK (DVB-S/S2)
Symbol rate 1-45 MS/s
LNB power
0/18 V, 500 mA
RF loop frequency range
950-2150 MHz
RF output
Frequency range 110-860 MHz
Ouput level / impedance 90 dBµV / 75 Ω
C/N > 50 dB
MER > 35 dB
Modulations QPSK. QAM16. QAM64
Channel width
7/8 MHz
Guard Interval 1/4. 1/8. 1/16. 1/32
FEC 1/2. 2/3. 3/4. 5/6. 7/8
Transmission mode
Maximum bitrate
31.66 Mb/s
Output level adjustment
0...-15 dB, 0.5 dB step
Power 5.5 VDC, 1.5 A
Weight 0.7 kg
Dimensions 47.5x117x220.5 mm
Electrostatic discharge caution

The module contains electrostatic sensitive components. To minimize electrostatic discharge, observe the following precautions:
  • Do not remove module from its anti-static plastic bag until you are ready to install it into the base unit.
  • Hold the module only by its front panel.
  • Do not place the module on an unprotected surface. Immediately after you remove the module from the base unit, you must insert it into its anti-static plastic bag.
  • When the module is not in use, keep it in its anti-static plastic bag.
  • Do not ship or store the module or base unit in/near strong electrostatic, electromagnetic or radioactive fields.