<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title> drmRADIO: Improved reception </title> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <meta http-equiv="content-language" content="en"> <meta name="description" content="drmRADIO: Improved reception on European website about DRM (Digital Radio Mondiale)"> <meta name="page-topic" content="Improved reception"> <meta name="keywords" content="drm, radio, drm radio, drm radios, drmradio, external antennas, internal antennas, long waves, medium waves, short waves, ferrite rod, wire antenna, loop antenna, active antenna"> <meta name="revision" content="110821-en revision 8.6"> <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>Improved Reception</h1> For weak stations the internal ferrite rod and telescopic antennas of receivers are insufficient and an external antenna must be used. The cheapest solution is 10-12 metres of copper wire from the house to a tall tree, preferably with a transformer balun and a shielded feeder. If this is not possible, a loop antenna may be used succesfully indoors. Such antennas are available as individual components or kits, whereas active antennas are normally preassembled. <br> </div> </div> </div> <div id="mainbox"> <div class="maincolumn1"> <h2>Wave Propagation</h2><br> Radio waves behave like light, travel in straight lines and are in principle limited to the horizon. However, just like light they may be reflected and refracted, and this can happen in the D, E and F ionised layers that extend from 50 to 400 km above the surface of the earth. The layers are created by the rays from the sun and absorb and reflect radio waves depending on their frequency, the solar activity, season and time of day, affecting the propagation.<br> <br> >> <a href="Radioboelgers udbredelse-en.htm"> read more </a><br><br><br> <img src="UniWave Di-Wave 100 (178 x 125).jpg" width="135" height="95" border="0" alt="UniWave Di-Wave 100"> <br><br> <em>UniWave Di-Wave 100 with ferrite and telescopic antennas.</em> </div> <div class="maincolumn2"> <h2>Wire Antennas</h2><br> Internal antennas are not sufficient for weak stations and an external antenna must be used. The cheapest solution is a 10-12 metre copper wire to a tall tree, preferably with a transformer balun some dis-<br>tance from the house connect-<br>ed with a shielded cable. The strongest signal is achieved with an antenna tuner that matches the antenna system at the actual frequency. The necessary parts may be bought individually or in kit form with pre-cut wire lengths.<br> <br> >> <a href="Traadantenner-en.htm"> read more </a><br><br><br> <img src="Thieking Draht10 Langdraht and RF-Systems Magnetic Longwire Balun (135 x 95).jpg" width="135" height="95" border="0" alt="Thieking Longwire Antenna and RF-Systems MLB balun"> <br><br> <em>Thieking wire antenna with RF-Systems MLB balun.</em> </div> <div class="maincolumn3"> <h2>Loop Antennas</h2><br> A loop antenna is a magnetic device with directional properties that is capable of suppressing interfering stations at the reception frequency. The antenna is largely insensitive to electrical noise fields and may also be used indoors. A shielded loop antenna can be built from plastic tubing and coaxial cable, but requires tuning with a capacitor at each frequency. The most versatile solution is a ready-made loop antenna with an integral broadband amplifier.<br> <br> >> <a href="http://www.dxing.com/tnotes/tnote09.pdf" target="new"> Using the loop antenna </a><br><br><br> <img src="Wellbrook Communications Active Loop Antenna LFL 1010 (118 x 95).jpg" width="118" height="95" border="0" alt="Wellbrook Communications Active Loop Antenna LFL 1010"> <br><br> <em>Wellbrook Communications active loop antenna LFL 1010.</em> </div> <div class="maincolumn4"> <h2>Active Antennas</h2><br> An antenna with amplifier may be located on the roof of a house or car, connected with shielded cable. Thus the anten-<br>na can be kept clear of the electrical noise that would interfere with its performance inside. A good match is also achieved between the integral amplifier and antenna whip even at short antenna lenghts. The power supply is always placed indoors and often feeds the amplifier through the cable. Good active antennas are somewhat expensive.<br> <br> >> <a href="http://www.arrl.org/files/file/Technology/tis/info/pdf/0109031.pdf" target="new"> What is an active antenna </a><br><br><br> <img src="Procom AAC 1 10 kHz-110 MHz Active Antenna (126 x 95).jpg" width="126" height="95" border="0" alt="Procom AAC 1 10 kHz-110 MHz Active Antenna"> <br><br> <em>Procom AAC 1 10 kHz-110 MHz active outdoor antenna.</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>