DVB-S/S2 (16x8PSK/QPSK) to 8xDVB-T (COFDM) Transmodulator: TERRA TDX-4168 (FTA)



Terra TDX-4168 R81625 transmodulator is used for reception of DVB-S/S2 (8PSK/QPSK) signals, selection of desired channels and retransmission of them in COFDM format in chosen RF channels in VHF/UHF frequency range. The device allows the user to receive and manage a range of free DVB-S/S2 (8PSK/QPSK) satellite channels and convert them to DVB-T (COFDM) channels. One TDX-4168 R81625 panel can receive all channels from 16 satellite transponders and convert them into two independent groups with four neighboring DVB-T multiplexes (each multiplex with maximum throughput of 31.66 Mbps.
In practice, each multiplex can carry 6 SD channels or 2-3 HD channels. The administrator of the system selects the required channels from the satellite streams and forms the eight DVB-T multiplexes. Each DVB-T multiplex can be programmed from satellite channels coming from two different satellite transponders. In each case, it is necessary to remember about 10% safety margin when determining the maximum bit rate for the whole multiplex (typically the ultimate bit rate of a multiplex should not exceed 29 Mbps). The output DVB-T COFDM multiplexes are usually distributed to users by a passive network composed of RF splitters/taps. Such a solution is especially convenient in modern hotel TV systems distributing a variety of satellite channels, including HD broadcasts.
Thanks to RJ-45 Ethernet port, the programming of the TDX-4168 R81625 panel is performed via a web browser.
The TDX-4168 R81625 unit is dedicated for receiving FTA satellite channels. In the case of encrypted channels, the suitable model is TDX-420C R81619.
A great advantage of the Terra device is easy integration with other components:
The R81625 units can be mounted on the R82538 or R82539 DIN rail (also in a RACK cabinet) and powered from DR-60-12 R82532 or UP413 R82533 power supply.
Key features
  • conversion of DVB-S/S2 signals from 16 satellite transponders to eight DVB-T COFDM multiplexes,
  • TDX-4168 creates two independent groups of 4 neighboring DVB-T multiplexes (eight DVB-T MUXes, each with max throughput of 31.66 Mbps),
  • built-in remultiplexer allowing for free selection of channels in DVB-T multiplexes,
  • selectable channels and services (filtering),
  • easy control via RJ-45 port,
  • management via the Internet,
  • access to event history (logs),
  • automatic gain control (AGC).
View of the configuration window of the TDX-4168 R81625 transmodulator
(incl. main parameters of eight DVB-S/S2 streams: RF level, SNR, VBER/PER, bit rate)
Selection of channels and filtration of services
The TDX-4168 R81625 transmodulator creates two independent groups with four neighboring DVB-T multiplexes. With these parameters, the maximum bandwidth of each of the eight DVB-T multiplexes is 31.66 Mbps, in compliance with the DVB-T standard.
Example of mounting TERRA headend to CD001 housing with DIN rail BD001 R90001. Additionally, there are the SRM-522 R80522 multiswitch and an Ethernet switch mounted on the ID001 R90003 mounting plate. The whole system has the FD001 R90002 ventilation unit with thermostat added.
LNB: QUATRO Inverto HOME ProDVB-S/S2 (8PSK, QPSK) to 8xDVB-T (COFDM) Transmodulator: TERRA TDX-480 (FTA)Power Supply: TERRA UP413 (12V/4.5A, for Terra modules)Switching Power Supply Terra PS202F (20V 2A, Digital SCR)Single-cable Cascadable dSCR Multiswitch: Terra SRM-522 (950...2150MHz/290...2340MHz, class A, passive terr. TV path)Satellite Dish TELMOR 120 TT Standard (white)4-way Tap: Signal O-4-12dB (5-1000MHz)4-way Tap: Signal O-4-12dB (5-1000MHz)4-way Tap: Signal O-4-12dB (5-1000MHz)4-way Tap: Signal O-4-12dB (5-1000MHz)
An example of SMATV system. Thanks the application of the SRM-522 R80522 multiswitch, the system can distribute satellite channels selected from the whole Ku band (11.7 ... 12.75 GHz).

DIPOL offers the following transmodulators of DVB-S/S2 (8PSK, QPSK) signals:
 Model TDX-410C  TDX-420   TDX-420C TDX-440   TDX-480
   R81617  R81618 R81619  R81638  R81639 
 R81617  R81618 R81619   R81614 R81621
Input signals
Number of transponders
1 2 2 8 8
Output signals
Number of MUXes 1 2 2 4 8
Max. bit rate [Mbps]  31.66 2x31.66 2x31.66 4x31.66 8x31.66
CI slot
1x No 2x No No
Customers can also order DVB-S/S2--> DVB-C (QAM) transmodulators.
Configuration of DVB-S/S2 (8PSK, QPSK) - DVB-T (COFDM) TERRA transmodulator
(example: tdx-480 R81621)


Product type Transmodulator
Name tdx4168
Conversion DVB-S/S2--->DVB-T
RF input Number of supported transponders 16
Number of F-connectors 2
Channels FTA (uncoded) Yes
Coded (CI slot) No
Specyfikacja techniczna
RF input Frequency range MHz 950...2150
Power supply/control 0/13/18 V & 22 kHz, max. 1 A,DiSEqC 1.0, EN50607, EN50494
standard DVB-S/S2
Modulation QPSK, 8PSK
Symbol rate Ms/s 2...45
Signal strength dBµV 55...95
Impedance Ohm 75
RF throughput - gain dB -1 ± 1
RF output standard DVB-T/ISDB-T
Number of DVB-T MUXes 8 (2 × 4 nearby)
Modulation QPSK, QAM16, QAM64
Frequency range MHz 170...230, 470...862
Signal strength dBµV 90
Signal pos. adjustment dB 0...15 with step 1 dB
Impedance Ohm 75
MER dB ≥35
Channel bands MHz 7,8
Security interval 1/4, 1/8, 1/16, 1/32
FEC 1/2, 2/3, 3/4, 5/6, 7/8
FFT mode 2K
Bandwidth Mbps 8 × 31,67
RF combiner Frequency range MHz 47...862
Connector F
Loss dB 2,5
Configuration Port RJ-45 (web browser)
IP address
Remote Yes
Current drawn V/A DC 12/1.2
Operating temperature °C 0...+45
Weight kg 1,12
Dimensions mm 63 × 198 × 112