{"id":5703,"date":"2012-12-13T16:42:56","date_gmt":"2012-12-13T16:42:56","guid":{"rendered":"http:\/\/rsgbbeta.org\/?page_id=5703"},"modified":"2024-02-27T12:48:20","modified_gmt":"2024-02-27T12:48:20","slug":"emerging-emc-problems","status":"publish","type":"page","link":"https:\/\/rsgb.org\/main\/technical\/emc\/emerging-emc-problems\/","title":{"rendered":"Sources of EMC problems"},"content":{"rendered":"<p><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-4464\" src=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_what-does-plt-sound-like.png\" alt=\"Headphones and Signal Trace\" width=\"193\" height=\"147\" srcset=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_what-does-plt-sound-like.png 193w, https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_what-does-plt-sound-like-150x114.png 150w\" sizes=\"auto, (max-width: 193px) 100vw, 193px\" \/><\/strong><\/p>\n<p>New Technology often introduces new RFI threats to the spectrum<\/p>\n<p>This page summarises the topics currently \u00a0under\u00a0investigation by the EMC Committee and provides links to published reports on these topics<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Broadband VDSL\u00a0<\/strong><\/p>\n<ul>\n<li>VDSL members Survey September 2017<\/li>\n<li>VDSL Drive by Measurements November 2017<\/li>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/12\/VDSL-RFI-RSGBOfcom-meeting-June-21-2017.pdf\">VDSL RFI RSGB:Ofcom meeting-June 21 2017<\/a><\/li>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2019\/10\/vdsl-ofcom-final-report_v2-.pdf\">vdsl-RSGB -final-report_o<\/a>n testing with Ofcom<\/li>\n<li>Ofcom <a href=\"https:\/\/www.ofcom.org.uk\/research-and-data\/tv-radio-and-on-demand\/radio-research\/spectrum-assurance-analysis-of-bt-openreach-vdsl\">spectrum-assurance-analysis-of-bt-openreach-vdsl<\/a><\/li>\n<li>October 2019 <a href=\"https:\/\/rsgb.org\/main\/blog\/news\/gb2rs\/headlines\/2019\/10\/11\/rsgb-meets-ofcom-to-discuss-vdsl-issues\/\">rsgb-meets-ofcom-to-discuss-vdsl-issues<\/a><\/li>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2019\/10\/VDSL-RFI-Update-Ofcom-meeting-Oct-2019V2-4to3.pdf\">Presentation given at VDSL-RFI-Update-Ofcom-meeting-Oct-2019<\/a><\/li>\n<li><a href=\"https:\/\/rsgb.services\/public\/publications\/emc\/191011_ofcom_letter_re_rsgb_vdsl_meeting_8_october_2019.pdf\">Response from Ofcom_ofcom_letter_to_rsgb_vdsl_meeting_oct_2019<\/a><\/li>\n<\/ul>\n<p>Green Energy<\/p>\n<ul>\n<li>LED Lighting<\/li>\n<li><a title=\"Solar PV panels\" href=\"https:\/\/rsgb.org\/main\/technical\/emc\/solar-pv-panels\/\">Solar Panels<\/a><\/li>\n<li>Wind Farms<\/li>\n<\/ul>\n<p>Switched Mode Power Units (SMPU)<\/p>\n<p>Plasma TV&#8217;s<\/p>\n<p><a href=\"https:\/\/rsgb.org\/main\/news\/special-focus\/pla-plt\/\">Powerline Telecommunications &#8211; PLT<\/a><\/p>\n<p><strong>This page contains some \u201csound bites\u201d of past and current PLT systems, as an aid to identification of interference sources.<\/strong><\/p>\n<p>Most data-over-mains devices are \u201cnotched\u201d so that they do not cause high levels of emissions on amateur bands. However, elsewhere in the shortwave spectrum there remains the possibility of interference.<\/p>\n<h3>Interference outside notched frequencies<\/h3>\n<!--[if lt IE 9]><script>document.createElement('audio');<\/script><![endif]-->\n<audio class=\"wp-audio-shortcode\" id=\"audio-5703-1\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB4-SimpView.mp3?_=1\" \/><a href=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB4-SimpView.mp3\">https:\/\/rsgb.org\/main\/files\/2013\/08\/SB4-SimpView.mp3<\/a><\/audio>\n<audio class=\"wp-audio-shortcode\" id=\"audio-5703-2\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB3-SimpFullSpd.mp3?_=2\" \/><a href=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB3-SimpFullSpd.mp3\">https:\/\/rsgb.org\/main\/files\/2013\/08\/SB3-SimpFullSpd.mp3<\/a><\/audio>\n<audio class=\"wp-audio-shortcode\" id=\"audio-5703-3\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB2-Comt-No-dataC.mp3?_=3\" \/><a href=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB2-Comt-No-dataC.mp3\">https:\/\/rsgb.org\/main\/files\/2013\/08\/SB2-Comt-No-dataC.mp3<\/a><\/audio>\n<p><em><strong>PLT Data Transfer one device<\/strong><\/em><\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-5703-4\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB1-Comt-singleC.mp3?_=4\" \/><a href=\"https:\/\/rsgb.org\/main\/files\/2013\/08\/SB1-Comt-singleC.mp3\">https:\/\/rsgb.org\/main\/files\/2013\/08\/SB1-Comt-singleC.mp3<\/a><\/audio>\n<p>&nbsp;<br \/>\n<\/h3>\n<h3>Comtrend Powerline adaptors (shipped as part of the BT Vision package)<\/h3>\n<ul>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_Radiopra11MHzW.wav\">Interference to short-wave broadcast<\/a> (first without interference then PLAs switched on) (WAV file, 308Kb)<\/li>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_AComtNodata.mp3\">Two PLAs idling<\/a> (no data being passed) (MP3 file, 518Kb)<\/li>\n<li><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_BComtMovieCTL.mp3\">Two PLAs exchanging data<\/a> (MP3 file, 491Kb)<\/li>\n<\/ul>\n<h3>Two types of access PLT recorded at Crieff during the trial in November 2002<\/h3>\n<h4>A) The Mainnet system<\/h4>\n<p>Recorded about 3m from the house on the 7MHz amateur band. This is described as a spread spectrum system. Interference depends on the density of traffic. Recording starts with light traffic increasing as the recording proceeds.<\/p>\n<p><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_MN_1.wav\">Listen <\/a>(WAV file, 63Kb)<\/p>\n<h4>B) The Ascom system<\/h4>\n<p>Recorded about 4m from the house in one of the \u201cdelivery\u201d frequency bands. This system uses three discrete frequency bands, below 10MHz, to deliver signals to the house. The bands are about 1MHz wide.<\/p>\n<p><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_delivery.wav\">Listen<\/a> (WAV file, 84Kb)<\/p>\n<h4>C) The Ascom system<\/h4>\n<p>Recorded about 4m from the house in one of the \u201cin-house\u201d frequency bands. This system uses three discrete frequency bands above 10MHz to distribute signals in the house.<\/p>\n<p><a href=\"https:\/\/rsgb.org\/main\/files\/2012\/11\/EMC_PLT_inhouse.wav\">Listen<\/a> (WAV file, 84Kb)<\/p>\n<p>If you are having problems with other technologies please <a href=\"https:\/\/rsgb.org\/main\/about-us\/committees\/electromagnetic-compatibility-committee\/contact\/\" target=\"_blank\" rel=\"noopener\"><strong>contact the EMCC<\/strong><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>New Technology often introduces new RFI threats to the spectrum This page summarises the topics currently \u00a0under\u00a0investigation by the EMC Committee and provides links to published reports on these topics &nbsp; Broadband VDSL\u00a0 VDSL members Survey September 2017 VDSL Drive by Measurements November 2017 VDSL RFI RSGB:Ofcom meeting-June 21 2017 vdsl-RSGB -final-report_on testing with Ofcom [&hellip;]<\/p>\n","protected":false},"author":27,"featured_media":0,"parent":353,"menu_order":8,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-5703","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/pages\/5703","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/users\/27"}],"replies":[{"embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/comments?post=5703"}],"version-history":[{"count":0,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/pages\/5703\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/pages\/353"}],"wp:attachment":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/media?parent=5703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}