{"id":530,"date":"2009-12-20T16:36:44","date_gmt":"2009-12-20T21:36:44","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=530"},"modified":"2011-10-15T06:53:26","modified_gmt":"2011-10-15T10:53:26","slug":"ukqrm-and-the-fight-against-noise","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2009\/12\/ukqrm-and-the-fight-against-noise\/","title":{"rendered":"UKQRM And The Fight Against Noise"},"content":{"rendered":"
\"The<\/a>

The noisy cuprits--Comtrend's power line adapters.<\/p><\/div>\n

Whether you’re new to shortwave radio listening or have been an amateur radio operator for years, more than likely you’ve occasionally encountered electrical interference, that annoying hum or buzz that permeates your listening experience. This noise can often be difficult to pinpoint or eliminate. For most of us, the common culprits are\u00a0fluorescent lights, computer monitors, televisions or even so-called “wall warts” (those\u00a0ubiquitous\u00a0AC adapters we use for most consumer electronics). For those of us living in sparsely populated rural areas, we can more easily find noisy interference in our own homes or on our farms (electric fences are notorious sound interrupters). If you live in an urban area, identifying interference can be a constant battle, since it may be the new LCD TV of the couple living in the apartment above you.<\/p>\n

Or, even worse, the source of radio interference could be installed in your neighbors’ homes, in the form of a nationally mass-marketed home entertainment device promoted by your telephone company. That was the case for SWLer Mike Trodd in the United Kingdom; his neighbors installed a “BT Vision<\/a>” multimedia entertainment package with Comtrend power line adaptors offered by British Telecom<\/a>. “I switched on my short wave set to find a loud +20db screaming noise on all\u00a0HF frequencies,” Mike describes. “Initially I suspected the actual home hub, but soon worked out it was the\u00a0power line adaptors that were the cause.”<\/p>\n

\"Figure<\/a>

Figure 1 - Shortwave interference from PLT devices. Click to enlarge.<\/p><\/div>\n

The fact is, these power line adapters use a smaller scale, more local version of a technology that amateur radio operators have long fought<\/a>–namely “BPL”, or Broadband over Power Lines<\/a>. In this case, though, Comtrend’s power line adapters turn your home’s electrical system into a communications system–also called Power Line Telecom (PLT)<\/a>. This novel (and possibly illegal) device has one crippling side-effect:\u00a0 loud broadband noise across most of the shortwave radio listening spectrum (see figure 1).<\/p>\n

What did Mike do after discovering the source of his interference? He contacted the authorities, and upon learning that, despite laws protecting radio, there is no effort being made at enforcement, he founded a program to fight the interference. “I created UKQRM<\/span><\/a> because once I discovered the source,” he says, “I was disgusted that it was being allowed and nothing was being done at all!”<\/p>\n

So, how bad is the noise, anyway? Take a look at Mike’s first homemade video:
\n<\/object><\/p>\n

It’s pretty obvious that the interference is substantial and will deafen shortwave and ham radios. How did British Telecom respond to Mike’s well-documented evidence of the problem?\u00a0 “[They] were dreadful!” he exclaimed.”Initially you just can’t get any information out of anyone. Their dreadful overseas call centres are a waste of time. Only when a letter was sent to the chairman was any kind of reply received.”\u00a0 But even this was less than satisfactory.\u00a0 “To date,” he adds,”BT has never communicated its point of view.”<\/p>\n

Are you safe from PLT interference if you don’t live in the UK? “PLT is already rolling out, uncontrolled,” Mike states, “across the EU. Portugal is suffering greatly as there are not even notches. In the US, PLT again is gathering speed. As successive governments give this illegal equipment the green card; I see a day when the HF spectrum is lost to us all.”<\/p>\n

I asked Mike what radio operators and listeners can do? “We need support from radio listeners; in the main, this needs to be [in] an education role. Tell anyone who will listen about this. Point out that PLT does not meet regulations and laws and yet it’s being driven by the EU and governments, driven over the people with no regard at all.”<\/p>\n

I urge you to take a look at UKQRM’s website<\/a>\u00a0(15 Oct 2011 update: site now called “Ban PTL<\/em>)\u00a0and see what you can do to fight interference on our radio spectrum.<\/p>\n

Mike, on behalf of all radio listeners, thank you for fighting the good fight!<\/p>\n","protected":false},"excerpt":{"rendered":"

Whether you’re new to shortwave radio listening or have been an amateur radio operator for years, more than likely you’ve occasionally encountered electrical interference, that annoying hum or buzz that permeates your listening experience. This noise can often be difficult to pinpoint or eliminate. For most of us, the common culprits are\u00a0fluorescent lights, computer monitors, […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[8,3],"tags":[202,198,199,211,210,200,201,212,4089,197,195],"class_list":["post-530","post","type-post","status-publish","format-standard","hentry","category-articles","category-news","tag-bpl","tag-bt","tag-bt-vision","tag-comtrend","tag-comtrend-power-line-adapters","tag-mike-trodd","tag-plt","tag-power-line-telecom","tag-qrm","tag-radio-interference","tag-ukqrm"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-8y","jetpack-related-posts":[{"id":7480,"url":"https:\/\/swling.com\/blog\/2013\/10\/document-radio-interference-via-the-ofcom-spectrum-management-survey\/","url_meta":{"origin":530,"position":0},"title":"Document radio interference via the Ofcom Spectrum Management Survey","author":"Thomas","date":"October 3, 2013","format":false,"excerpt":"Nige (G7CNF) recently contacted me regarding a survey he has created to help document and fight radio interference from power line technology and other sources. If you live in the UK and can create an Ofcom case reference number, please consider contributing. Nige writes: I have created a new forum\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"PLT devices can produce broad spectrum noise on the shortwave\/amateur radio HF bands","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2013\/10\/PowerLineTechnologies.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":13325,"url":"https:\/\/swling.com\/blog\/2015\/05\/dave-says-not-all-jameco-power-supplies-are-linear-and-regulated\/","url_meta":{"origin":530,"position":1},"title":"Dave says not all Jameco power supplies are linear and regulated","author":"Thomas","date":"May 23, 2015","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who replies to a post published yesterday regarding some of Jameco linear power supplies. Dave writes: \"A bit of a caveat on Jameco\u2019s these so called Linear power supplies. This is based from my own experiences so is not fiction. Bottom\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"Note that not all power supplies are listed as \"regulated linear\"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=700%2C400 2x"},"classes":[]},{"id":48268,"url":"https:\/\/swling.com\/blog\/2021\/03\/jack-finds-that-chokes-have-a-huge-impact-on-switching-power-supply-noise\/","url_meta":{"origin":530,"position":2},"title":"Jack finds that chokes have a huge impact on switching power supply noise","author":"Thomas","date":"March 28, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Jack Dully, who writes: I was putting some things in my radio junk parts box and came across some chokes. So I tried a test with my Tecsun PL-880 on battery and the Tecsun supplied switching AC adapter, with and without chokes on the\u2026","rel":"","context":"In "Ham Radio"","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":15055,"url":"https:\/\/swling.com\/blog\/2015\/10\/guest-post-london-shortwaves-guide-to-mitigating-urban-radio-interference\/","url_meta":{"origin":530,"position":3},"title":"Guest Post: London Shortwave’s guide to mitigating urban radio interference","author":"Thomas","date":"October 9, 2015","format":false,"excerpt":"Many thanks to SWLing Post\u00a0contributor, London Shortwave, who is kindly sharing this guest post--a brilliant article he recently posted on his own website. I'm very grateful: one of the most common questions I'm asked by readers is how to cope with the radio interference so many listeners and amateur radio\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"London-Urban-City","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/10\/London-Urban-City.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/10\/London-Urban-City.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/10\/London-Urban-City.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":48313,"url":"https:\/\/swling.com\/blog\/2021\/03\/guest-post-indoor-noise-and-ferrites-part1\/","url_meta":{"origin":530,"position":4},"title":"Guest Post: Indoor Noise and Ferrites, Part1","author":"Thomas","date":"March 30, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, TomL, who shares the following guest post: Indoor Noise and Ferrites, Part 1 by TomL My magnet wire loop antenna on the porch reminded me to revisit aspects about my noisy Condo that I still needed to understand.\u00a0 Some RF noise I could control\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/03\/TVSignal.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/03\/TVSignal.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/03\/TVSignal.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/03\/TVSignal.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":13316,"url":"https:\/\/swling.com\/blog\/2015\/05\/how-to-replace-a-noisy-wall-power-supply\/","url_meta":{"origin":530,"position":5},"title":"How to replace a noisy wall power supply","author":"Thomas","date":"May 22, 2015","format":false,"excerpt":"Regarding noisy switching power supplies, SWLing Post reader, Dan Lewis, comments: \"Google the following: \u201cJameco linear wall transformer\u201d, and you\u2019ll find a suitable non-switching replacement. Jameco still has a number of linear transformers in their catalog at reasonable prices. I haven\u2019t bought anything from them in many years but when\u2026","rel":"","context":"In "AM"","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"JamecoWallPowerSupply","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoWallPowerSupply.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/530","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=530"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/530\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=530"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=530"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=530"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}