TRANSRADIO – We have your Solution .... with a high number of transmitters, AM
broadcasting requires just ... in 1998 and developed a digital radio standard
which is endorsed ..... Block Diagram of the Automatic Equalizer Adjustment ...
ALL UNDER ONE ROOF
TRANSRADIO – We have your Solution
2
CONTENT
DRM (Digital Radio Mondiale) – Radio goes future – we show IT ............4 ❙ Overview of the DRM Solution ...............................................................5 ❙ TRANSRADIO Rides on DRM Potential ...............................................6/7 ❙ DRM – The Economical Way to reach your Listeners.............................8 ❙ SFN – Extend the Coverage ....................................................................9 ❙ Fraunhofer DRM ContentServer™ R4.............................................10/11 The new DRM DMOD3 – The All in One Solution....................................12 ❙ Features..................................................................................................13 ❙ Supported DRM Modes.........................................................................13 ❙ Harddisk-free Design, VSWR Measurement ........................................14 ❙ DRM Reserve and Fall Back Systems....................................................15 ❙ Optimization of the DRM Spectrum ......................................................16 ❙ Automatic Equalizer Adjustment – Speed up your Business..............17 TRAM Premium Line – Pure Efficiency in all Modes ...............................19 ❙ TRAM Premium Line Highlights ......................................................20/21 ❙ Paralleling Unit ......................................................................................22 ❙ Riding the Longwave.............................................................................23 ❙ Fraunhofer DT 700 DRM Monitoring Receiver......................................24 ❙ Remote Control and Error Tracking via SNMP and HTML ...................25 AM Antennas from TRANSRADIO – Designed for DRM .........................26 Antenna Tuning Devices, Diplexer, ENW ................................................27 DRM Consulting – Ask the Experts...........................................................28 Turnkey-ready Solution from the Market leader......................................29 Technical Data DRM DMOD3 ....................................................................30 Ports and Connectors DRM DMOD3 ........................................................31 3
DRM (DIGITAL RADIO MONDIALE) – Radio goes future – we show IT
he major advantage of LF, MF and HF broadcasting in the frequency range below 30 MHz is the huge achievable coverage. While all other technologies need an extensive network with a high number of transmitters, AM broadcasting requires just a few transmitters, providing a program to particular target groups in a large geographical area. Because listeners were accustomed to the high quality of VHF/FM broadcasting, upgrading AM with a new technology was required to deliver the same high standards. Implementing the digital broadcasting technology DRM gives substantial improvements in audio and reception quality.
T
❙ ❙ ❙ ❙ ❙ ❙
Robustness in fading channels Significant improvement in audio quality Power savings at the transmitter site Service related data (service labels, alternative frequencies and language information) Data services (pictures, text- and traffic information) News Service JournalineTM
Digital Radio Mondiale (DRM) is the name of the international consortium, which defined the standards for digitalisation of AM broadcasting. DRM was founded in 1998 and developed a digital radio standard which is endorsed by the IEC, ETSI and ITU. TRANSRADIO, formerly TELEFUNKEN SenderSysteme Berlin, as a founding member of this consortium, has tremendously influenced this standard with its experience and knowledge in broadcasting. TRANSRADIO has established itself as the leading DRM provider. Today TRANSRADIO has the highest number of installed DRM transmitters in service. 4
Optional Fraunhofer DRM ContentServerTM R4 MDI data
Audio
OVERVIEW OF THE DRM SOLUTIONS
TRAM TX1
GPS-antenna or external clock
RFdrive
RFout
DRM DMOD3
ENV1
Paralleling unit Antenna Antenna
RF RFback (directional coupler)
TRAM TX2 ENV2 RFout
RFdrive
Optional Fraunhofer DRM Monitoring Receiver DT 700
RFback
5
TRANSRADIO RIDES ON DRM POTENTIAL
TRANSRADIO has established itself as the world’s leading DRM provider. Today, TRANSRADIO has the highest number of installed DRM transmitters in service.
DRM Medium Wave Transmitting Station Cremlingen MW 800kW MW transmitter TRAM/P 800 Carrier power of 800kW (>400kW DRM) in Cremlingen/ Braunschweig (Germany) Marnach MW 600kW
MW transmitter TRAM/P 600 Carrier power of 600kW (>300kW DRM) in Marnach (Luxembourg) Heusweiler MW 400kW
MW transmitter TRAM/P 400 Carrier power of 400kW (>200kW DRM) in Heusweiler (Germany)
6
Please find more references on our
DRM Long Wave Transmitting Station Zehlendorf LW 500kW
LW transmitter TRAM/P 500L Carrier power of 500kW (>250kW DRM) in Zehlendorf (Germany) Donebach LW 500kW
LW transmitter TRAM/P 500L Carrier power of 500kW (>250 kW DRM) in Donebach (Germany) Summerhill LW 300KW
r website www.transradio.de/references
LW transmitter TRAM 300L Carrier power of 300kW (>150 kW DRM) in Summerhill (Ireland)
7
DRM – THE ECONOMICAL WAY TO REACH YOUR LISTENERS
The DRM power is normally given as the average power of the digital modulation. Because of the high modulation peaks of the DRM signal, the average power is significantly lower than for the same transmitter operating in the analog AM mode. In general a DRM COFDM waveform has a peak to average ratio of about 10 dB. Thus a standard DRM transmitter with a carrier power of 100kW and 100% modulation reaches a peak power of 400kW. The DRM power of such a transmitter is only 40 kW. As a result, for the same coverage, up to 60% of the power can be saved running an AM transmitter in DRM.
8
In contrast to standard transmitters, TRANSRADIO’s TRAM family of transmitters attain a DRM power of up to 73% of their nominal power with all quality requirements fulfilled: the MER value is well above the minimum DRM requirement and the out-of-band emissions are considerably within the DRM spectrum mask. This is possible due to the overmodulation capability of the TRAM transmitters and a peak-to-average ratio reduction scheme implemented in the DRM DMOD3. Thus, TRANSRADIO’s TRAM family of transmitters produce nearly two times the DRM power compared to a standard transmitter.
SFN – EXTEND THE COVERAGE
SFN-Berlin: 3 TRAM 10, 1485 kHz
A single frequency network (SFN) is a radio network that operates several transmitters on a single frequency and has overlapping coverage areas. SFN’s are an efficient method of extending the coverage area without the need for additional frequencies. Signals arriving from transmitters outside the local transmitter area can reinforce reception and recover losses through local anomalous propagation effects. Any receiver in the coverage area of these transmitters will receive the signal from more than one transmitter. Different paths that arrive from distant transmitters in the SFN must arrive with a delay separation that is less than the guard interval duration, or otherwise inter-symbol interference occurs. To avoid interference, each station is run synchronously with the others using GPS as a reference clock. The built-in GPS receiver of the DRM DMOD3 from TRANSRADIO is implemented for single frequency networks. Tests in the medium wave band, conducted in cooperation with MEDIA BROADCAST GmbH and in the short wave band, in cooperation with the DRM consortium demonstrated the readiness of the DRM DMOD3 for all types of SFN's.
9
OVERVIEW
FRAUNHOFER DRM CONTENTSERVER™ R4
Optional Fraunhofer DRM ContentServerTM R4 MDI data
Audio
Overview of the DRM ContentServerTM R4
Audio
Data
DRM AudioServer
DRM Multimedia DataServer
DRM Multiplex Generator
GPS
The Fraunhofer DRM ContentServer™ R4 is designed to meet all the demands of DRM broadcasters, DRM network providers and DRM transmitter operators with regard to DRM Multiplex generation. The system is typically located in the studio or a playout center or at the transmitter site – with full remote control for administration and data provision. The Fraunhofer DRM ContentServer™ R4 is based on robust and redundant 19” server hardware for reliable 24/7 operation. The Fraunhofer DRM ContentServer™ R4 provides triple functionality:
Config Interface
Remote Configuration/ Administration
FAC SDC MSC MDI / DCP Interface
DRM Modulators
DRM Audio Server With multi-stream real time audio encoding DRM Multimedia Data Server Providing all standardized as well as proprietary mechanisms for data application import, preparation, encoding and broadcast DRM Multiplex Generator Managing the extensive DRM signalling capabilities, generating the full digital DRM Multiplex and providing standard MDI/DCP output streams. The system can easily be scaled to match individual requirements and to support proprietary data applications.
10
The system has 3 major interfaces: Configuration and Administration: The system is designed to be administered remotely using any modern HTML browser. The system status is available via remote HTML interface (including detailed status information), automatic e-mail report system, local status monitor, relay board signalling and SNMP. Audio and Data Input: For audio input, the system supports up to 4 digital AES/EBU or up to 4 analog stereo signals. In addition, playlists and mp3 files can be uploaded to the system for offline audio encoding. Data for multimedia applications can be provided using a variety of standard protocols (e.g. FTP, HTTP, RSS, UECP, Leitungsprotokoll, Funkhaustelegramm). Powerful mirroring features provide automatic and scheduled data updates e.g. from FTP, HTTP and RSS sources on the web. DRM Multiplex Output via MDI/DCP: The complete digital DRM multiplex generated by the Fraunhofer DRM ContentServer™ R4 can be fed simultaneously to any number of DRM modulators or monitoring stations for multi-frequency or SFN broadcasts. The output stream uses the standardized MDI/DCP protocol supported by all standard compliant DRM modulators and monitoring equipment via UDP/IP based or serial connections.
Features of the DRM ContentServerTM R4 Public Network Content Contribution
Firewall / Security
Protected Privat Network Broadcast Distribution Chain Administration (Webbrowser)
Audio 1-4 Streams (live/playlist)
Time sync GPS, ntp
DRM Audio Server
MDI / DCP
4 x (AAC, CELP,HVXC)
TM
DRM Multiplex Generator
Data Application DRM Text Messages News Service Journaline MOT Slideshow MOT Broadcast Website TPEG Traffic Information EPG-Electronic Program Guide TOP News TMC-Traffic Message Channel
DRM Multimedia Dataserver
SNMP
Local / long distance Any number of simultaneous outputs (SFN) IP uni-/multicast RS-232
Analoge/ Email Relay Local status/ ISDN notification card Config menu Modem
System Status
11
THE NEW DRM DMOD3 - THE ALL IN ONE SOLUTION
12
OVERVIEW E
DRM DMOD3
E
New Features: Operation modes ❙ Operation modes AM, DRM, SCS and MCS Fast switchover ❙ Fast switchover is accomplished in less than 5 seconds between all operation modes
he aim of the new DRM DMOD3 is to offer highly automated configuration procedures, maximum reliability, low power consumption, low heat dissipation and a compact and ergonomic design. All broadcasting modes are possible. The DRM DMOD3 offers easy and fast switchover facility between analog AM, pure DRM, single channel or multi channel simulcast. Core features of the new DRM exciter are the automatic equalizer adjustment and the integrated antenna voltage standing wave ratio (VSWR) measurement capability, which offers a very precise and fast method to set up DRM equipment. The DRM DMOD3 is designed for mounting in standard 19” racks of 4U height. It eliminates the requirement for a separate RF processor and offers a significant reduction in external wiring. Low power consumption, reduced operating temperature and a higher MTBF have been achieved by implementing notebook technology components and a harddisk-free design.
T
Automatic Equalizer Adjustment ❙ Easy signal correction with automatic equalizer adjustment VSWR Measurement of the Antenna
Integrated RF Processor ❙ The DRM DMOD3 fits into a single 4RU Case ❙ Significant reduction of external wiring Low Power Consumption ❙ Harddisk-free design ❙ Use of notebook components Ergonomic Design ❙ Increased display size of 8.4” ❙ Provides a resolution of 800x600 for easy readability ❙ Simple to operate without the need of a external keyboard Improved Reliability ❙ Harddisk-free design for better MTBF ❙ Wide ambient temperature range up to 50 °C
Now all DRM-Modes fully supported! Mode A
Mode B
Mode C
Mode D
Nominal Bandwidth (9/10 kHz)
✔
✔
✔
✔
Half Bandwidth (4.5/5 kHz)
✔
✔
✔
✔
Double Bandwidth (18/20 kHz)
✔
✔
✔
✔
64QAM MSC, all Code Rates
✔
✔
✔
✔
16QAM MSC, all Code Rates
✔
✔
✔
✔
16QAM SDC
✔
✔
✔
✔
4QAM SDC
✔
✔
✔
✔
Standard Modulation
✔
✔
✔
✔
Hierarchical Modulation
✔
✔
✔
✔
Equal Error Protection
✔
✔
✔
✔
Unequal Error Protection
✔
✔
✔
✔
Long/Short Interleaving
✔
✔
✔
✔ ✔ = supported
13
VSWR MEASUREMENT, HARDDISK-FREE DESIGN
Dual-flash storage architecture: Safe like a safe
Harddisk-Free Memory Architecture The new memory architecture of the DRM DMOD3 offers maximum reliability due to the harddisk-free design. All necessary data to boot up and to run the DMOD3 are stored on a static permanent storage (flash1), which has read only access. Inessential dynamic data for logging and configuration, which are written
Static permanent storage
Example of an Antenna VSWR
VSWR Measurement of the Antenna The DRM broadcast must be compliant with the ITU spectrum mask and requires low antenna VSWR. The DRM DMOD3 is capable of measuring the VSWR of the antenna during DRM operation and to show the result on the screen. This enables the broadcaster to monitor antenna matching during regular operation without additional measuring equipment. Furthermore the DRM spectrum is measured and is visualized by the integrated DRM DMOD3 web server.
14
Startup Programs Permanent config
Flash1
Mandatory - Read only
occasionally, are stored on a second flash memory (flash 2). This separation of the essential and inessential data on two flash storage devices was made to increase the reliability of the architecture, since the likelihood of failure of a flash memory is determined mainly by the number of write cycles.
Dynamic permanent storage Log files Dynamic configuration
Flash2 Inessential for normal operation
Data Processing
Memory Architecture
Dynamic volatile storage Temporary data Fast logging
RAM Disk
DRM RESERVE AND FALL BACK SYSTEMS
DRM DMOD3 -A
Active DRM Reserve MDI
The active DRM reserve offers a maximum of reliability for a DRM system. Two DRM exciters supervise each other during normal operation. In the unlikely event of failure of one DRM exciter, the remaining exciter takes over the service and MDI keeps the transmitter(s) on air. In an active reserve, double Audio exciter system the test points of the transmitter(s) are switched as well.
RF, Envelope Audio
Antenna
TX
Antenna
Supervision Link
RF, Envelope
DRM Exciter Fall-Back Solution The exciter fall-back solution gives MDI the opportunity to fall back from DRM transmission to AM, DAM or Audio AMC modulation in the unlikely event of failure of the digital exciter. In fall back mode the audio signal bypasses the digital exciter. The internal synthesizer of the transmitter provides the RF signal and the transmitter is kept on air by means of the internal AM modulator.
TX Control Unit
RF from TX-Synthesizer
DRM DMOD3 RF
RF
Envelope Envelope Audio Audio
Control Unit
Combination of Active DRM Reserve and DRM Exciter Fall-Back In order to further increase the reliability of the DRM system, the Active DRM Reserve and the Exciter Fall-Back Solution can be combined. In the unlikely case of the failure of both DRM exciters the internal synthesizer of the transmitter provides the RF signal.
15
OPTIMIZATION OF THE DRM SPECTRUM
The DRM DMOD3 provides automatic functions to pre-equalize the transmitted signal in order to minimize the out-of-band emissions. The aim of the pre-equalization process is to reduce the influence of linear and non-linear distortions on the DRM signal. The following pre-equalization functions are supported by the DRM DMOD3:
Optimisation Process
H (j)
, DC
AM/AM
AM/PM
Compensation of Non-linear Distortion I
Compensation of Non-linear Distortion II
Compensation of Linear Distortions
Adjustment of the Time Delay and the DC Offset
❙ Measurement of the amplifier characteristic (AM/AM characteristic)
❙ Measurement of the incident phase modulation (AM/PM characteristic)
❙ Measurement of the envelope frequency response
❙ The DRM DMOD3 offers a sophisticated algorithm for optimal adjustments between the delay differences of the amplitude- and phase signal as well as the DC offset.
❙ Calculation of a correction curve ❙ Pre-equalization of the transmission signal
❙ Calculation of a correction curve ❙ Pre-equalization of the transmission signal
❙ Calculation of an equalization filter to compensate the amplitude frequency response and the group delay distortions ❙ Pre-equalization of the transmission signal
16
SPEED UP YOUR BUSINESS
One Button Automatic Equalizer Adjustment Broadcast operators demand an automated configuration procedure for DRM equipment and the DRM DMOD3 is the answer. The DRM DMOD3 provides automated functions to pre-equalize the transmit signal in order to reduce out-of-band emissions. The equalizer adjustment can be performed automatically just by the push of a button.
The DRM DMOD3 auto-adjust of the equalizer offers: ❙ Automatic initial equalizer adjustment ❙ Equalizer optimization during DRM operation ❙ Adaptive equalization ❙ Automatic switching of up to three different test points ❙ Crucial parameters like time delay, DC offset and envelope frequency response are optimized in order to minimize out-of-band emissions
DRM DMOD3 Equalizer
MDI
MDI Decoder & OFDM Generator
I,Q
I-Q to A-Phi Conversion
Phi
Delay Adjustment A
A-Phi Delay
Upsampling & RF-Output
Envelope Filter Filter Coefficients
Phase modulated RF
TX
Envelope
DC-Offset
DRM DMOD3 Auto - Adjust
Test Point 1
Test Point 2
RF-Input & Downsampling
Measuring Point Switching device
Test Point 3
Block Diagram of the Automatic Equalizer Adjustment
17
TRAM PREMIUM LINE – PURE EFFICIENCY IN ALL MODES
TRAM 10
18
TRAM 50
TRAM 100
OVERVIEW TRAM TX1
TRAM TX2
The TRAM Premium Line – optimized for DRM Transmission any years of experience in the field of high power transmitters in conjunction with the latest state of the art transistor technology has paved the way for a future oriented and meanwhile well established solid state transmitter concept. As opposed to conventional transmitters the simple modular system of solid state medium wave transmitters from TRANSRADIO offers a maximum of flexibility and unsurpassed audio quality. The TRAM Premium line based on the new developed power modules secures optimized DRM parameter while achieving an outstanding overall efficiency in all operation modes.
M
All TRAM Premium line transmitters are optimized for digital transmission and exceed the DRM recommendations. The layout, in standard 19" racks, allows for easy and comfortable access to all components and modules and results in exceptionally low space requirement for the respective power classes. The power amplifier stage offers true modular redundancy through the use of standardized 1 kW amplifier modules. Each individual module is equipped with an on-board PDM modulator and no quantization problems occur. Designed with a high power reserve capability, each module provides full signal quality on its own.
TRAM 400
19
TRAM PREMIUM LINE HIGHLIGHTS
TRANSRADIO
TRAM-transmitters, prefered models Type No. of 50kW- Power blocks No. of identical power modules No. of driver modules Output power (other power classes on request)*) Frequency range LW MW
Operation modes RF Output
Connector Load impedance VSWR
Modulation system AF range
❙ Outstanding efficiency and excellent performance data ❙ ≥125 % positive peak programme capability ❙ DAM operating mode for further energy saving (standard for all models, DCC by jumper setting) ❙ Compact and service-friendly design, extremely low space requirement ❙ Modular design of the power amplifiers: standard 1 kW plug-in power module, broadband over the whole MF range, no tuning of the modules is required. Integrated supervision and protection circuits are standard features. ❙ All transmitters are exclusively air-cooled utilising a unique internal air-flow system. Recycled air cooling by means of air-water heat exchangers available. ❙ Factory fitted and tuned to the desired operating frequency. ❙ Rugged construction with emphasis placed on high mechanical strength and stability.
AF Frequency response AF harmonic Distortion (THD) Modulation capability Carrier shift (amplitude drop) RF harmonics and spurious emissions Signal to noise ratio Frequency stability AF Input Power supply
Power consumption Overall efficiency**) Control
❙ All TRAM Premium line transmitters are optimized for digital modulation techniques such as DRM.
20
Local Remote
Environmental conditions
Cooling system Dimensions [mm] (LW TXs require more filter racks)
❙ Combining stand alone transmitters by utilising an innovative paralleling unit (PU). No need for a highpower reject load. ❙ TRAM Premium line transmitters are also available as long wave broadcast transmitters (150 to 300 kHz) and long wave communication transmitters (14 to 148 KHz)
Voltage Frequency Voltage variations Power factor m=0 m=1
Temperature Relative humidity Installation altitude Width Depth Height
TRAM – Essentials at a Glance LW communication transmitters: LW broadcast transmitters: MW broadcast transmitters: Output power range:
14 kHz to 148 kHz 150kHz to 300kHz 525 kHz to 1710 kHz stand-alone version 5kW to 600 kW combined up to 2000 kW
AM TRANSMITTERS – A SECURE INVESTMENT INTO THE FUTURE
TRAM 5
TRAM 10
TRAM 25
TRAM 50 1 48 1 50 kW
TRAM 100 TRAM 200 TRAM 300 TRAM 400 TRAM 500 TRAM 600 2 4 6 8 10 12 5 10 24 96 192 288 384 480 576 – – 1 2 4 6 8 10 12 5 kW 10 kW 25 kW 100 kW 200 kW 300 kW 400 kW 500 kW 600 kW 150 kHz to 300 kHz 525 kHz to 1710 kHz Factory fitted and tuned to the determined operating frequency Components for change to other frequencies on request AM (A3E) – AM reduced power P/4 – DAM (X3E), i.e. dynamic carrier control – AM stereo capability, prepared for DRM 7/8“ EIA 1 5/8“ EIA 3 1/8“ EIA 4 1/2“ EIA 6 1/8“ EIA 9“ EIA 50 ⍀ unbalanced VSWR 1.3 tuneable, automatic power reduction as a result of increasing VSWR during operation Pulse Duration Modulation (PDM) 30 Hz to 10 kHz Changeover between a maximum of 2 band limiting filters on request
0.5 dB, 30 Hz to 10 kHz, with band limiting filters switched off 1% at m = 0,8 100% continuously, + 125% peak programme capability 1% with voltage regulation Standard: according to ITU-R SM 329 or better ( 50mW), FCC requirements on request 60 dB referred to 100% Modulation Deviation 5Hz, external synchronisation of synthesizer possible 600 ⍀ balanced (can be changed inside the unit by jumper to 2000 ⍀) Adjustable from –10dBm to +10dBm referred to 100% modulation, switched coarse increments (5dB), fine adjustment by potentiometer Standard mains configuration: 3 N 400V;TN-S or TN-C, other voltages on request, TRAM 200 or higher MV supply preferred 50Hz (60 Hz on request) 5% with full performance; ± 10% with minor performance degradation 0.9 0.95 6.7 kW 12.2 kW 29,8 kW 57,5 kW 114,9 kW 229,9 kW 344,8 kW 459,8 kW 574,7 kW 689,7 kW 10,0 kW 18.3 kW 44,6 kW 86,2 kW 172,4 kW 344,8 kW 517,2 kW 689,7 kW 862,1 kW 1034,5 kW > 75% > 82% > 84% 87% OFF/ON, full power/on, reduced power(P/n) – AM/DAM – selection local/remote Changeover between 2 AF band limiting filters – various status indications by LED Command input by floating contacts, same commands as for local control, indications by floating contacts RS 232 standard and BIT BUS, SNMP, HTML optional Standard: –10 °C to +50°C, other environmental temperatures on request maximum 95%, non-condensing Standard: maximum 2000 m, higher altitudes on request Air cooling (intake air from the room, exhaust air to the room, air duct system with blowers on request) 600 600 1200 1800 3000 4800 6000 9600 10800 12000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 2000 2000 2000 2000 2000 2500 2500 2500 2500 2500 *) All other power ranges on request
**) with standard cooling
TRANSRADIO – RF and Power are our Strength 21
PARALLELING UNIT
The paralleling unit (PU) serves to combine two single transmitters to double the output power. Furthermore, it provides an active redundancy system to avoid a loss of transmission during maintenance schedules. The PU equipment contains a central control unit, a combining network and a compact balancing resistor. The load regulation of the central control unit ensures that both transmitters are levelled automatically to equal RF output powers and a minimum of power is lost on the balancing resistor. In the unlikely event of failure of one of the transmitters, a motorised RF switch will automatically switch the unaffected transmitter directly to the antenna and the faulty transmitter to a dummy load. The transmission continues and the faulty transmitter can be repaired whilst connected to the dummy load.
OVERVIEW
RFout
Paralleling unit A
RFbac (direct couple
PU Control Unit
22
RIDING THE LONGWAVE
Long Wave Transmitter TRAM/P 500L (500kW) from TRANSRADIO in Zehlendorf Longwave is well known for excellent ground wave coverage hence, offering a stable reception. DRM on LW combines the advantages of digital transmission with very good longwave propagation. On the other hand, narrow band longwave antennas with considerable mismatch even inside the transmission bandwidth are posing a big challenge to the broadcast industry. TRANSRADIO has accepted this challenge and has successfully modernized several LW transmission stations with its DRM solution. The DRM installation on LW needs completely to fulfill the requirements concerning the out-ofband emissionsof ETSI EN 302 245-1 and ITU SM.1541. Therefore, TRANSRADIO implements an Extension Network (ENW) to eliminate the disadvantages of the asymmetrical antenna impedance and to reduce mismatch. This results in a reduction of the standing wave ratio and a significant mask reserve. A world premier was achieved when the TRANSRADIO transmitter in Zehlendorf (Germany) broadcast for the first time DRM on long wave in accordance with the ETSI/ITU standard. Since then TRANSRADIO reconfirmed impressively its leading position with respect to LW and has modernized LW transmitting stations, for example, in Donebach, Aholming (Germany) and Summerhill (Ireland).
Long Wave-Antenna in Zehlendorf (360m)
Spectrum of the transmitted Signal in Zehlendorf
Burg Mainflingen
Kalundborg, DK
Burg, Mainflingen and Kalundborg are Signals received from other Stations
23
OVERVIEW
FRAUNHOFER DT 700 DRM MONITORING RECEIVER
(directional coupler)
rive
Concept The DRM Monitoring Receiver DT 700 is a professional monitoring receiver perfectly suited for DRM reception and transmitter monitoring. It features a high performance front-end based on the latest direct sampling reception technology. Together with a 12-band fix-tuned preselector filter bank, the DRM Monitoring Receiver DT 700 guarantees an outstanding reception performance and low phase noise. The receiver's signal processing is based on a Software Defined Radio (SDR) construction. Its core is an embedded Linux PC. The latter features an easy software update via built-in DVD drive. The highly reliable hardware is built for 24/7 continuous operation as is necessary for a professional broadcast environment. Based on the embedded Linux platform a web server allows easy remote access to all of the receiver's control functions. The DRM Monitoring Receiver DT 700 is available with two different reference oscillator accuracies – standard oscillator (5ppm, Option B1) or high precision OCXO (
