<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title> drmRADIO: Digital broadcasting </title> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <meta http-equiv="content-language" content="en"> <meta name="description" content="drmRADIO: Digital broadcasting on European website about DRM (Digital Radio Mondiale)"> <meta name="page-topic" content="Digital broadcasting"> <meta name="keywords" content="drm, radio, drmradio, digital radio, digital broadcasting, digital radio mondiale, long waves, medium waves, assignment, itu circular letter ccrr/20, ge75, VSWR, linear transmitter, drm transmitter, drm transmitters, spark, spark drm transmitter, i/q, a/rfp, mdi"> <meta name="revision" content="110821-en revision 8.8"> <meta name="author" content="niels dreijer"> <meta name="publisher" content="http://drmradio.dk"> <meta name="copyright" content="niels dreijer"> <meta name="generator" content="hand coded"> <meta name="formatter" content="hand coded"> <meta name="robots" content="index, follow"> <meta name="audience" content="all"> <meta name="rating" content="safe for kids"> <link rel="stylesheet" href="screen.css" type="text/css" media="screen"> <link rel="stylesheet" href="print.css" type="text/css" media="print"> <script type="text/javascript"> function showPopup(url){ newwindow=window.open(url,'name','width=585,height=280,top=200,left=300,menubar=0,resizable=1,scrollbars=0,toolbar=0'); if (window.focus) {newwindow.focus()} } </script> </head> <body> <div class="wrapper"> <div id="imprint"> <div class="drmlogo"> </div> <div class="news"> <h2>DRM Radio News</h2><br> 30.08.2016<br> <a href="http://www.drm.org/?p=4403" target="new"> DRM during IBC 2016<br> </a> <br> 10.06.2013<br> <a href="The future of the AM bands (EBU tech-i 16, page 13).pdf" target="new"> Future of the AM bands<br> </a> <br> 13.09.2010<br> <a href="http://www.drm.org/?p=1327" target="new"> DRM video transmission<br> </a> <br> 01.07.2010<br> <a href="http://www.drm.org/?p=1334" target="new"> 82 DRM stations for India<br> </a> <br> 11.09.2009<br> <a href="http://www.drm.org/wp-content/uploads/2012/10/drm_receiver_profiles1.pdf" target="new"> DRM receiver profiles<br> </a> <br> 31.08.2009<br> <a href="http://www.drm.org/wp-content/uploads/2012/10/DRM-System-Specification.pdf" target="new"> Revised DRM standard<br> </a> <br> <h2>News Archive</h2><br> <a href="http://mediumwave.info/newsarchive_d.html" target="new"> mediumwave.info<br> </a> <br> <br> <h2>DRM Radio Schedules</h2><br> International <a href="http://www.baseportal.com/cgi-bin/baseportal.pl?htx=/drmdx/pdf" target="new"> frequencies </a> <br> <a href="BBC & DW Schedule DRM Summer 2011.pdf" target="new"> BBC/DW</a> schedule<br> Current <a href='Aktuel radioudbredelse-en.htm' onClick='showPopup(this.href);return(false);'> HF propagation </a> <br> <br> <h2>DRM Radio Leaflet</h2><br> PDF file for <a href="Leaflet.pdf" target="new"> printing</a> <img src="PDF icon bold (11 x 12 pixel).jpg" width="11" height="12" alt="PDF icon"><br> <br> <br> <h2>About drmRADIO.dk</h2><br> This website is written by industry professionals<br> <br> <br> <h2>Contact</h2><br> <a href="kontakt.htm" title="Contact" onmouseover="this.href='mai' + 'lto:' + 'inf%6F' + '@' + 'drm%52ADIO.%64k'" onfocus="this.href='mai' + 'lto:' + 'inf%6F' + '@' + 'drm%52ADIO.%64k'"> <img src="info@domainname.bmp" width="111" height="13" border="0" alt="info@domainname"> </a> </div> <div class="counter"> </div> <div class="copyright"> Copyright &#x00a9; 2008-2016<br>drmRADIO.dk<br> <br> </div> </div> <div id="header"> <div class="menubarleft"> | <a style="text-decoration: none; color: #2D38A1" href="default-en.htm" rel="nofollow"> Return to Main Page </a> | </div> <div class="menubarright"> | <a style="text-decoration: none; color: #2D38A1" href="http://en.wikipedia.org/wiki/Kalundborg_Transmitter" target="new"> DRM from Denmark </a> | <a style="text-decoration: none; color: #2D38A1" href="http://www.drm.org" target="new"> DRM Association </a> | <a style="text-decoration: none; color: #2D38A1" href="http://tech.ebu.ch/digitalradio" target="new"> EBU Technical </a> | </div> <div id="topbox"> <div class="topbody"> <div style="color: #2D38A1"> <h1><font color="red">digital</font> Broadcasting</h1> It is possible to transmit in DRM even on a small budget. The system is non-proprietary with non-commercial software of high quality for modulation, decoding, logging and coverage verification. Small linear transmitters up to 10-25 kW are well suited for DRM, larger transmitters on medium and especially long waves require modification of the antenna system. Short waves are unproblematic, and DRM is a low cost shortcut to feed remote FM radio transmitters. <br> </div> </div> </div> <div id="mainbox"> <div class="maincolumn1"> <h2>Spectrum Availability</h2><br> ITU Circular Letter CCRR/20 stipulates that DRM broadcasts are compliant with the GE75 frequency plan, if the power of the digital transmissions is 7 dB under the internationally assigned power. A 750 kW AM assignment gives a parallel right to 150 kW DRM providing the national authority issues a supplementary notification to the ITU Radiocommunications Bureau, and the broadcaster may alternate freely between transmitting in 750 kW analogue and 150 kW digital.<br> <br> >> <a href="http://www.drm.org/wp-content/uploads/2012/10/DRM-Introduction-Implementation-Guide1.pdf" target="new"> DRM introduction guide </a><br><br><br> <img src="DRM Introduction and Implementation Guide (134 x 95-pixel).jpg" width="134" height="95" border="1" alt="DRM Introduction and Implementation Guide"> <br><br> <em>Introduction Guide gives a practical overview.</em> </div> <div class="maincolumn2"> <h2>Encoders and Modulators</h2><br> Encoding of the DRM signal can take place in the modulator, or centrally as MDI (Multiplex Distribution Interface) for distribution via UDP/IP. Programming and data are then fed to a content server, with the modulator at the transmitter site acting as only a client. In addition to commercial hardware-based products at various price levels, non-commercial PC software of high quality for MDI or direct modulation of the transmitter is available.<br> <br> >> <a href="Enkodere og modulatorer-en.htm"> read more </a><br><br><br> <img src="Fraunhofer DRM ContentServer R5 (173 x 95).jpg" width="173" height="95" border="0" alt="Fraunhofer DRM ContentServer R5"> <br><br> <em>Fraunhofer DRM ContentServer R5 generates an MDI signal.</em> </div> <div class="maincolumn3"> <h2>Transmitters and Antennas</h2><br> Digital transmitters require a resistive load with symmetrical reactive components. Due to the high sideband energy content of digital modulation, antennas on medium and particularly long waves have difficulty achieving the necessary VSWR d" 1,4:1 5 kHz. For linear transmitters this is a minor issue, whereas non-linear transmitters cannot compensate for excess return power and may interfere heavily outside the channel spectrum mask.<br> <br> >> <a href="Sendere og antenner-en.htm"> read more </a><br><br><br><img src="Smith chart VSWR 1.4 circle (132 x 95 pixel).jpg" width="132" height="95" border="0" alt="VSWR 1,4:1 circle"> <br><br> <em>Smith chart with VSWR 1,4:1 limit of DRM transmitters.</em> </div> <div class="maincolumn4"> <h2>Equipment Suppliers</h2><br> Modern I/Q modulated transmitters, AM or SSB amplifiers can normally be converted to transmit DRM at 15-40 percent of the rated power, whilst older transmitters with A/RFP may have too low bandwidth. Manufacturers can often modify their existing transmitters, and the modulator/content server Spark is free for DRM test transmissions with simple linear exciters, or to generate MDI and I/Q signals.<br> <br> >> <a href="Senderfabrikanter-en.htm"> read more </a><br><br><br> <img src="BBC Devon Trial (168 x 95).jpg" width="168" height="95" border="0" alt="BBC Devon Trial"> <br><br> <em>Audio configuration and station ID of BBC Devon trial.</em> </div> </div> <div id="footer"> <div class="logotypedk"> <a href="default-en.htm" rel="nofollow"> <img class="logotype" src="drmRADIO logotype (saturated bottom) 192 x 30 pixel.jpg" border="0" alt="Return to Main Page"> </a> </div> </div> </div> </div> </body> </html>