{"id":25589,"date":"2017-05-10T09:11:06","date_gmt":"2017-05-10T13:11:06","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=25589"},"modified":"2017-05-10T09:11:06","modified_gmt":"2017-05-10T13:11:06","slug":"on-shortwave-radio-diversity-reception","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2017\/05\/on-shortwave-radio-diversity-reception\/","title":{"rendered":"On shortwave radio diversity reception"},"content":{"rendered":"

\"\"<\/a><\/p>\n

Many thanks to SWLing Post<\/em> contributor, London Shortwave<\/a>, who recently shared this post from the blog, Making It Up<\/a>:<\/p>\n

\n

Shortwave Radio Diversity Reception<\/h3>\n

Shortwave radio diversity reception provides a way to combine several fluctuating signals and get a solid result. It provided the foundation for most radio news received in America for years.\u00a0<\/span><\/p>\n

During World War II, most countries around the world relied on Britain\u2019s shortwave radio broadcasts for the latest news from Europe. In the days before transatlantic audio cables or satellites, distant news traveled fastest by radio. Networks in the America\u2019s, Australia, New Zealand and elsewhere re-broadcast shortwave\u00a0radio news domestically.<\/p>\n

Getting reliable, good quality audio programs over shortwave is always a challenge because of fading<\/a>. As signals bounce off the ionosphere, they split over multiple paths. Often they fade and flutter, sometimes significantly, as the nature of the layers change with time. Here are several examples of shortwave signals fading<\/a>, so you know what it sounds like. Skywave radio signals are subject to complex patterns of travel and interference.<\/p>\n

Eventually, domestic networks found a clever way to get better audio from these distant signals.<\/p>\n

[…]Diversity reception works like this. Instead of one signal, you monitor several signals at once and blend them together. Harold Beverage and RCA pioneered work\u00a0on shortwave radio diversity reception in 1920\u2019s. Commercial solutions arrived by 1933. Typically, you would use three receivers with three different antennas, spaced 1,000 feet apart. When antennas are widely spaced, signals arrive with different fading.\u00a0Just combine the signals and let the strongest signal dominate. As long as the fading is not correlated across all three antennas, improvement can be significant.<\/p>\n

Diversity reception can be achieved in several ways. The most popular \u2013 spatial diversity \u2013 is described above. Other methods include frequency diversity \u2013 mixing together the same program received on several different channels.[…]<\/p>\n

Continue reading…<\/a><\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Many thanks to SWLing Post contributor, London Shortwave, who recently shared this post from the blog, Making It Up: Shortwave Radio Diversity Reception Shortwave radio diversity reception provides a way to combine several fluctuating signals and get a solid result. It provided the foundation for most radio news received in America for years.\u00a0 During World […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[3,288,43],"tags":[6185,2704,34],"class_list":["post-25589","post","type-post","status-publish","format-standard","hentry","category-news","category-radio-history","category-shortwave-radio","tag-diversity-reception","tag-london-shortwave","tag-shortwave"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-6EJ","jetpack-related-posts":[{"id":50625,"url":"https:\/\/swling.com\/blog\/2021\/10\/ham-radio-workbench-episode-explores-diversity-reception\/","url_meta":{"origin":25589,"position":0},"title":"Ham Radio Workbench episode explores Diversity Reception","author":"Thomas","date":"October 23, 2021","format":false,"excerpt":"I just finished listening to the most recent episode of the Ham Radio Workbench with John Fallows (VE6EY) as a guest. John is an SWL and Ham Radio operator and speaks at length about how he uses diversity reception to mitigate persistent local RFI (radio frequency interference). If you have\u2026","rel":"","context":"In "Antennas"","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/SDRplay-RSPduo-Antenna-ports.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/SDRplay-RSPduo-Antenna-ports.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/SDRplay-RSPduo-Antenna-ports.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/SDRplay-RSPduo-Antenna-ports.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":38438,"url":"https:\/\/swling.com\/blog\/2019\/07\/sdrplay-rspduo-sdruno-update-now-adds-diversity-reception\/","url_meta":{"origin":25589,"position":1},"title":"SDRplay RSPduo: SDRuno update now adds diversity reception!","author":"Thomas","date":"July 10, 2019","format":false,"excerpt":"Many thanks to Andy with SDRplay who notes: We are pleased to announce the release of v1.32 of SDRuno. The purpose of this release is primarily to add MRC Diversity functionality for the RSPduo, but it also contains other fixes and additions based on customer feedback. Diversity functionality is described\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\/2019\/07\/SDRuno-Diversity.png?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":38010,"url":"https:\/\/swling.com\/blog\/2019\/05\/hamvention-highlights-affordable-diversity-reception-with-the-sdrplay-rspduo\/","url_meta":{"origin":25589,"position":2},"title":"Hamvention Highlights: Affordable diversity reception with the SDRplay RSPduo","author":"Thomas","date":"May 31, 2019","format":false,"excerpt":"Each year at the Dayton Hamvention I enjoy checking out the latest radio products and services. This year (2019) I found an exceptional number of innovations and will share these in Hamvention Highlights posts. If you would like to check out 2019 Hamvention Highlights as I publish them, bookmark this\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\/2019\/05\/9DE5153D-D28A-4B35-9291-E9673D9E02D0-e1559298699129-768x1024.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/05\/9DE5153D-D28A-4B35-9291-E9673D9E02D0-e1559298699129-768x1024.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/05\/9DE5153D-D28A-4B35-9291-E9673D9E02D0-e1559298699129-768x1024.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":2296,"url":"https:\/\/swling.com\/blog\/2011\/12\/silabs-brings-shortwave-to-car-radios\/","url_meta":{"origin":25589,"position":3},"title":"SiLabs brings shortwave to car radios","author":"Thomas","date":"December 3, 2011","format":false,"excerpt":"Silicon Labs, a manufacture of DSP (Digital Signal Processing) chips that are in many of the shortwave radios we feature here on SWLing.com, is now taking their technology to car radios. They have announced the\u00a0Si476x chip family which features\u00a0AM\/FM, longwave, shortwave (SW), NOAA weather band, FM RDS decoding and AM\/FM\u2026","rel":"","context":"In "Manufacturers"","block_context":{"text":"Manufacturers","link":"https:\/\/swling.com\/blog\/category\/manufacturers\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2011\/07\/silabslogo.gif?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":60083,"url":"https:\/\/swling.com\/blog\/2024\/06\/rtve-approves-additional-shortwave-transmitter-and-secures-the-future-of-the-public-shortwave-service\/","url_meta":{"origin":25589,"position":4},"title":"RTVE approves additional shortwave transmitter and “secures the future of the public shortwave service”","author":"Thomas","date":"June 28, 2024","format":false,"excerpt":"Many thanks to SWLing Post contributors, Paul Jamet and Tracy Wood for sharing the following article (translated into English) from RTVE: RTVE secures the future of the public shortwave service of Radio Exterior de Espa\u00f1a The RTVE Board of Directors has unanimously approved the purchase, installation, and implementation of a\u2026","rel":"","context":"In "International Broadcasting"","block_context":{"text":"International Broadcasting","link":"https:\/\/swling.com\/blog\/category\/international-broadcasting\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/08\/S-8800-Dial-Volume.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/08\/S-8800-Dial-Volume.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/08\/S-8800-Dial-Volume.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/08\/S-8800-Dial-Volume.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":20733,"url":"https:\/\/swling.com\/blog\/2016\/08\/200-metre-longwire-radio-verdad-4054-9-khz-guatemala-unprecedented-reception-in-oxford-uk\/","url_meta":{"origin":25589,"position":5},"title":"200 metre longwire: Radio Verdad 4054.9 kHz, Guatemala, unprecedented reception in Oxford, UK","author":"Clint Gouveia","date":"August 22, 2016","format":false,"excerpt":"Radio Verdad, Chiquimula,\u00a0Guatemala is quite a regular catch at home, however,\u00a0their modulation is nearly always weak as the carrier\u00a0struggles to lift above the ubiquitous blanket of local QRM. Another issue with hearing\u00a0this station is the\u00a0digital utility\u00a0signal just above 4055 kHz, thus requiring LSB reception to reject the adjacent noise. 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