{"id":177,"date":"2022-09-06T15:40:49","date_gmt":"2022-09-06T13:40:49","guid":{"rendered":"https:\/\/localdab.org\/?page_id=177"},"modified":"2022-09-10T22:04:36","modified_gmt":"2022-09-10T20:04:36","slug":"handy-rules-of-thumb","status":"publish","type":"page","link":"https:\/\/localdab.org\/index.php\/dab-in-simple-words\/handy-rules-of-thumb\/","title":{"rendered":"DAB+ tools"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">Handy rules of thumb<\/h3>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">The decibel (dB)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Compared to ordinary numbers dB-values \u200b\u200bare slightly different, because they are logarithmic and represents ratio\u2019s (divisions or multiplications).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But the following examples might help for power values:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-f56f613f wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<figure class=\"wp-block-table\"><table><tbody><tr><td>0dB = power x <strong>1<\/strong><\/td><td><\/td><\/tr><tr><td>3dB = power x <strong>2<\/strong><\/td><td>-3dB = divide by<strong> 2<\/strong>  (power x 0,5)<\/td><\/tr><tr><td>6dB = power x <strong>4<\/strong><\/td><td>-6dB = divide by <strong>4<\/strong>  (power x 0,25)<\/td><\/tr><tr><td>9dB = power x <strong>8<\/strong><\/td><td>-9dB = divide by <strong>8<\/strong>  (power x 0,125)<\/td><\/tr><\/tbody><\/table><figcaption>quick conversion of dB to power factors (multiplication)<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>10dB = power x <strong>10<\/strong><\/td><td>-10dB = divide by      <strong>10       (<\/strong>power x 0,1)<\/td><\/tr><tr><td>20dB = power x <strong>100<\/strong><\/td><td>-20dB = divide by     <strong>100<\/strong>      (power x 0,01)<\/td><\/tr><tr><td>30dB = power x <strong>1.000<\/strong><\/td><td>-30dB = divide by<strong>   1.000<\/strong>     (power x 0,001)<\/td><\/tr><tr><td>40dB = power x <strong>10.000<\/strong><\/td><td>-40dB = divide by <strong>10.000<\/strong>     (power x 0,0001)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Still a bit difficult, this website will do the math for you:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a rel=\"noreferrer noopener\" href=\"http:\/\/www.rapidtables.com\/electric\/dBW.htm\" target=\"_blank\">www.rapidtables.com\/electric\/dBW.htm<\/a><\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">Determining transmitter power<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">How powerful will my transmitter have to be with the antenna gain of my system with 100 Watts antenna input (transmitter power decremented with the antenna cable loss)?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You will find the answer here:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a rel=\"noreferrer noopener\" href=\"http:\/\/www.csgnetwork.com\/antennaecalc.html\" target=\"_blank\">www.csgnetwork.com\/antennaecalc.html<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Make sure you enter the amplification factor of your antenna in the correct unit !<br>Usually manufacturers provide the antenna gain in dBd, but it can also be specified in dBi.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Simply add +2.14dB to the dBd-value to get the gain of your antenna in dBi.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Or substract 2,14dB from the dBi-value to become the dBd-value.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because with dBi one takes an isotropic antenna as reference, with dBd one refers to a lambda\/2 dipole, that ratio is always 2.14 dB.<\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">Calculate intermodulation products<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Two transmitters on the same antenna tower without filters, is not a good idea. You will almost certainly get intermodulation products.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You can calculate at which frequencies these products will occur with the tools on the following website:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a rel=\"noreferrer noopener\" href=\"http:\/\/www.arcticpeak.com\/radiopages\/intermodulationproducts.htm\" target=\"_blank\">www.arcticpeak.com\/radiopages\/intermodulationproducts.htm<\/a><\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">Line of sight calculations<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">These can be done with the tool on the following websites:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a rel=\"noreferrer noopener\" href=\"https:\/\/www.qsl.net\/w4sat\/horizon.htm\" target=\"_blank\">www.qsl.net\/w4sat\/horizon.ht<\/a><a href=\"https:\/\/www.qsl.net\/w4sat\/horizon.htm\">m<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a rel=\"noreferrer noopener\" href=\"https:\/\/www.everythingrf.com\/rf-calculators\/line-of-sight-calculator\" target=\"_blank\">www.everythingrf.com\/rf-calculators\/line-of-sight-calculator<\/a><\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">RF calculator<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">On the following website you will find a handy &#8220;RF-calculator&#8221;:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"http:\/\/radiomobile.pe1mew.nl\/?RF_Aids:On-Line_calculators\" target=\"_blank\" rel=\"noreferrer noopener\">radiomobileonline.pe1mew.nl\/?RF_Aids:On-Line_Calculators: RF-Calculator<\/a><\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"has-large-font-size wp-block-heading\">DAB\/DAB+ capacity units calculator<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Check how many services you can broadcast in one MUX:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.opendigitalradio.org\/software\/capacity-units-calculator\" data-type=\"URL\" data-id=\"https:\/\/www.opendigitalradio.org\/software\/capacity-units-calculator\" target=\"_blank\" rel=\"noreferrer noopener\">www.opendigitalradio.org\/software\/capacity-units-calculator<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"http:\/\/localdab.org\/?page_id=28\">Back<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Handy rules of thumb The decibel (dB) Compared to ordinary numbers dB-values \u200b\u200bare slightly different, because they are logarithmic and represents ratio\u2019s (divisions or multiplications). But the following examples might help for power values: 0dB = power x 1 3dB = power x 2 -3dB = divide by 2 (power x 0,5) 6dB = power [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":28,"menu_order":90,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-177","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/pages\/177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/comments?post=177"}],"version-history":[{"count":20,"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/pages\/177\/revisions"}],"predecessor-version":[{"id":667,"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/pages\/177\/revisions\/667"}],"up":[{"embeddable":true,"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/pages\/28"}],"wp:attachment":[{"href":"https:\/\/localdab.org\/index.php\/wp-json\/wp\/v2\/media?parent=177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}