Dektec DTU-215 Test Report

TEST REPORT Digital TV Modulator

• Professional modulator for nearly every digital modulation standard • Ideal for use as a test signal modulator, for example, DekTec for receiver manufacturers • Capable of modulating transponder streams as well as test signals • Fully compatible with all HD standards DTU-215 • Plug&Play for Windows PC Gold Edition

136 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 12-01/2012 — www.TELE-satellite.com www.TELE-satellite.com — 12-01/2012 — TELE-satellite International — The World‘s Largest Digital TV Trade Magazine 137 TEST REPORT Digital TV Modulator

lation manual included by the manufacturer regard- The Gold Modulator ing the integration of the required drivers in the op- erating system (Windows One Modulator for XP/2003/Vista/2008 and Windows 7 are supported). This all functioned very easily with a double-click on the Every Terrestrial Digital installation assistant. The Stream Player Software, the modulator’s actual control TV Standard center, was just as quickly installed and set up only after we found it hidden behind a DTC-300 labelled Digital TV has a number of facturer. DekTec, a com- The little modulator box folder on the included USB different standards. Most of pany located in Holland, has doesn’t place too much of a stick. the terrestrial receivers that developed a multi-standard demand on the PC: an Intel we have introduced to you modulator just for this type Pentium III processor with Once all of the software here in the pages of TELE- of application. It’s ideally 1 GB of memory is enough needs were taken care of, satellite receive signals in suited to test terrestrial for almost all of the modula- we connected the modula- the DVB standard, for ex- receivers in different TV tor’s functions; in the case tor to our PC via the USB 2.0 ample, DVB-T (most often standards and to take these of DVB-T2, a more powerful port. Windows instantly rec- used for TV transmissions in digital TV signals and make processor would be needed, ognized the new hardware standard definition) and the them available in the VHF/ for example, an Intel Core 2 and set it up in just a few newer DVB-T2 (mostly used UHF range. Duo. seconds. for high resolution signals). For those receivers used All of the DekTec’s modu- All of the required drivers Before we can start test- with cable TV networks, it’s lator hardware is enclosed and the necessary software ing this modulator, a few mostly DVB-C while receiv- in an unremarkable, silver- are supplied by DekTec on basic settings have to be ers in the ISDB-T standard gray aluminum box that is a USB stick. This USB stick taken care of first. This in- are used in South America. 123 x 62 x 22mm in size. It not only contains the soft- cludes the modulation mode comes with a single USB 2.0 ware for the DTU-215, but as well as the desired output TELE-satellite test report- connector as well as the RF it also has DekTec’s en- frequency. The modulations ers can be found all over the signal output on both ends tire software palette. This are listed in Table 1. world and therefore have of the box. means the user has to direct access to their corre- search through all the files The user can select an sponding signal standards. If you’re all scratching on the USB stick to find the output frequency between But the same can’t be said your heads now trying to matching software for the 47 and 1000 MHZ in the for receiver manufacturers: a figure out where the in- DTU-215. VHF and UHF bands with receiver production line sim- put signal comes from and a bandwidth from 2.7 to 8 ply can’t be moved from one how the box gets its power, Overall, the workmanship MHz. The modulators sig- location to another for the DekTec has found a rather and packaging of the modu- nal output level for QAM is purpose of receiving live TV interesting solution: the lator left us with a very good between -46 and -15 dBm; signals in other standards. DekTec DTU-215 is designed impression; clearly, this is a with OFDM it lies between to be used with any stan- high-end product for use by -49 and -18 dBm. The mod- Obviously, it would be far dard PC and thus gets its professionals. ulator draws roughly 500mA better to bring the neces- power from thePC via the at 5V; this can be obtained sary signals to the manu- USB 2.0 interface. We referred to the instal- from a USB 2.0 interface so

138 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 12-01/2012 — www.TELE-satellite.com 1 2 5 6

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that an external power sup- modulation mode (for ex- worldwide satellite opera- To record such a stream those from a DVB-S2 tran- sented with three large text 1. The DekTec DTU-215 modulates a DVB-T signal from an original transponder stream via satellite ply is not necessary. ample, MPEG-2 or MPEG- tors are more likely to deal you can use a standard sponder with multiple HD fields that contain informa- 2. Signal measurement without artificially introduced 4). The more complete the with correct streams than DVB-S/S2 card for a PC (you channels. tion on the transponder errors All of the popular trans- stream is, the better the are smaller national opera- can find suitable cards in stream, which channels it 3. Signal measurement with artificially introduced port streams can be used. result at the modulator’s RF tors). this issue of TELE-satellite Streams stored in this contains, the PIDs that are errors through the modulator Since the box modulates output. on the overview pages of manner find their way 1:1 in in use and the data rate that 4. The signal curve in the spectrum with high output level the stream 1:1 and passes it In addition to a complete the award winning HDTV PC the Stream Player Software was used to send it. 5. The signal curve in the spectrum with low output on to the attached receiver, How do you recognize a PMT, you should look for card). which are then completely signal raw MPEG, AVI or even DivX complete stream and where numerous other features read and modulated into the Since the DekTec DTU- 6. Signal measurement with artificially introduced content is not suitable. The do you get it from? You of the individual channels This PC card communi- desired output data stream. 215 cannot receive a live in- errors through the modulator DTU-215 does not modify should direct yourself to a in the stream of the tran- cates with the PC through put signal and instead relies 7. Through the introduction of data containing errors, the display on our analyzer was significantly distorted the stream, rather, it pass- stream from a satellite op- sponder such as EPG, Sub- the PCI-e port so that there In the software’s main on a stream that is already 8. Clean image without any modulator introduced error es it along with all its infor- erator that is known for its title, teletext, multiple audio won’t be any problems re- window the user is pre- available, the Stream Player bits mation in the preselected proper streams (Tip: larger tracks or even encryption. cording large data rates like Norm SD HD Main Usage Areas Transmission Receiver DVB-T yes no Europe, Parts of Asia and Africa, Australia Terrestrial STB DVB-T2 yes yes Parts of Europe and Africa Terrestrial STB DVB-H yes no Parts of Europe and Asia Terrestrial Smartphone* DVB-C yes yes Europe Cable STB DVB-C2 yes yes Parts of Europe Cable STB QAM yes no Europe Cable, MVDS STB ISDB-TB yes yes South America Terrestrial STB ATSC yes yes North America Terrestrial STB DMB-TH yes yes China Terrestrial STB CMMB yes no China Terrestrial Smartphone*

Table 1: The most important modulation standards supported by the DTU-215 Gold Edition (*Note: If you are connecting to a SmartPhone without an antenna input jack, an external transmitter would be necessary)

140 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 12-01/2012 — www.TELE-satellite.com www.TELE-satellite.com — 12-01/2012 — TELE-satellite International — The World‘s Largest Digital TV Trade Magazine 141 1 4

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Software can play it back Software can simulate the The DTU-215 also lets 1. The Stream Player’s main window in an endless line; even loss of data packets, bit er- you adjust the signal level 2. Detailed information can be individual portions of the rors as well as entire byte between -46 and -15 dBm displayed for every PID in the transponder stream stream can be replayed. errors in amounts and fre- with QAM and between -49 3. Frequency selection in ISDB-T quencies that are user-se- and -18 dBm with OFDM. Mode As a professional unit, lectable. By looking at the screen- 4. Using the Channel Simulator the DTU-215 can also mod- shots that came with this function an AWGN signal can be created; even the transmission of ify the transport stream in This is an outstanding test report, you can clearly the signal can be simulated over ways that a user with nor- feature in that it allows you see how the signal curve multiple stations mal TV reception would to thoroughly test the input changes in the spectrum of 5. Through a total of six stations never want: it can artifi- sensitivity and error cor- our signal analyzer. the signal can be individually adjusted for attenuation and delay cially introduce errors. In rection capability of a re- 6. Various additional options in this way the Stream Player ceiver. Even the simulation of a DVB-T/H mode

142 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 12-01/2012 — www.TELE-satellite.com 7 8 7. Individual portions of the data 16 17 stream can easily be marked for playback 8. The modulator can introduce missing data packets into the output data stream 9. The modulator can introduce bit errors into the output data stream 10. The modulator can introduce byte errors into the output data stream 9 10

a test signal in any of the It became interesting DTU-215 SP nor are some the DekTec drivers. modulation standards as though when we tried to of the modulations (ISDB-T, well as an AWGN (Additive take an HDTV transpon- CMMB, DTMB). This would seem to be a White Gaussian Noise) sig- der with a total of three HD good time to point out that nal. If you introduce this channels and modulate it in If you have sufficient pro- DekTec offers not only Win- 11 12 AWGN signal to the actual DVB-T2. It was easy to see gramming experience, you dows drivers but Linux driv- 11. In Loop mode you can signal and manipulate its that the USB 2.0 port was can develop your own soft- ers as well although the customize the time information amplitude according to a at the limits of its capabili- ware with the help of the matching modulator control in the data stream Gauss curve, you can model ties. But if you reduce the C++ API available for down- software is not yet available 12. In addition to a transponder what would happen to the number of HD channels in load from the manufacturer for Linux; the user must de- stream, a test signal can also be generated, if desired, in any original signal if it should get the transport stream, it can that would access the at- velop it themselves using of the supported modulation disturbed by white noise. be processed without any tached hardware through the C++ API. standards problems. 13. Customizing the output level During our tests we were 14. Information on the hardware in use quite surprised at the high The DekTec DTU-215 is TECHNICAL 15. Even modulation of HD efficiency of the modula- available from the manufac- DATA content is possible without any tor and the relatively small turer in two versions: While Manufacturer DekTec Digital Video B.V., Van Riebeeckweg 43A, 13 problems load it placed on the PC. the DTU-215 Gold Edition 1212 EH Hilversum, The Netherlands 16. Detailed information on an We were able to modulate can handle every possible Email sales [email protected] HD channel a transport stream with five modulation including future Internet www.dektec.com 17. Thanks to Plug&Play, the DTU-215 is easily recognized in TV channels and multiple versions and can simulate Model DTU-215 Gold Edition the Windows Device Manager radio channels along with a complex signal distribu- Function USB 2.0 digital VHF/UHF Modulator all of the additional services tion network plus generate Frequency range 47 . . 1000 MHz (+/- 1ppm) 15 and display them on a TV an AWGN signal, these op- Bandwidth 2.7 .. 8 MHz via DVB-T. tions are not available in the Modulations ATSC VSB, ADTB-T/DTMB, CMMB, DVB-C, DVB-C2 DVB-T/DVB-H, DVB-T2, ISDB-T, QAM Expert Opinion MER (OFDM) > 42dB RF Connector 75 Ohm (F) The DekTec DTU-215 is a professional signal 14 Return loss 15dB (47 .. 862 MHz) modulator for nearly every digital modula- Level (QAM) -46 .. -15dBm (+/-2 dB) tion standard via satellite, terrestrial or cable. Level (OFDM) -49 .. -18dBm (+/-2 dB) Thanks to the multifaceted Stream Player + Amplitude Step Size 0.5dB Software, it makes an exceptional test instru- Adjacent Channel -54dB (QAM), -52dB (OFDM) ment and can also be used for demonstration Thomas Haring TELE-satellite Phase Noise < -95dBc @ 10kHz purposes. Test Center Austria Spectral Purity > 50dB ( 47 .. 1000MHz) No information is provided on which of the many drivers USB Port USB 2.0 – stored on the included USB stick are actually for use with Power (through USB 2.0) 5V, 500mA the modulator Dimensions 123 x 62 x 22 mm complex signal distribution and transmission system is possible with the DTU-215. You can use the box to introduce signal attenuation (in dB) at multiple transmission points as well as transmission delays (in µs).

You can even generate

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