{"id":35584,"date":"2019-01-14T05:00:05","date_gmt":"2019-01-14T09:00:05","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=35584"},"modified":"2019-01-14T08:08:59","modified_gmt":"2019-01-14T12:08:59","slug":"radio-receiver-innovations-over-the-last-century","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2019\/01\/radio-receiver-innovations-over-the-last-century\/","title":{"rendered":"Radio receiver innovations over the last century"},"content":{"rendered":"

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

(Source: Microwaves and RF)<\/a><\/p>\n

\n

A Selected History of Receiver Innovations Over the Last 100 Years<\/h2>\n

by\u00a0Brad Brannon<\/p>\n

This article, the first of a two-part series on receiver technology, looks at the genesis and early advances of this all-important area.<\/p>\n

Many contributed to the early days of wireless, but it\u2019s safe to say that Guglielmo Marconi ranks as one of the more prominent. While known for his wireless technology, many people are less familiar with the business he created around wireless technology at the turn of the 19th century. For about 20 years after the start of the 1900s, he built a critical business that launched the world of wireless toward what we have today.<\/p>\n

His commercialized technology was not the most up-to-date.\u00a0 However, it was good enough despite rapid technological changes because he figured out how to use the technology available to him to enable a new industry.<\/p>\n

Marconi set out to deploy a worldwide network capable of sending and relaying messages wirelessly at a time when the world was in turmoil at the end of colonialism, mainly due to the wars and disasters that pockmarked the start of the 1900s, including the sinking of the RMS Titanic in April\u00a0of 1912. The role that wireless played in both the rescue of survivors and the dissemination of the news of that accident reinforced the importance of this fledgling technology.<\/p>\n

The key role that wireless technology could play wasn\u2019t missed by either the public or the military, notably Joseph Daniels, who later became the secretary of the U.S. Navy. In the U.S. and elsewhere, leaders such as Daniels felt that the military should nationalize radio to ensure that they had access to it during wartime. It must be kept in mind that during this period, the only usable spectrum was below 200 kHz or so. At least for a while, things moved in this direction. After World War I, the government\u2019s control of wireless weakened, but not before the formation of the government-sanctioned monopoly that created the Radio Corporation of America (RCA).1<\/sup><\/p>\n

The Early Radio Days<\/strong><\/p>\n

By our expectations, the radios of Marconi\u2019s time were quite primitive. The transmitters employed spark-gap devices (only later did they employ mechanical alternators) to generate the RF. But on the receiving end, the systems were fully passive and consisted of an antenna, resonant LC tuner, and some sort of detector. These detectors will be covered shortly, but they were either mechanical, chemical, or organic.<\/p>\n

Some of these systems employed a battery simply to bias them, but not to provide any circuit gain as we might recognize today. The output from these systems was supplied to some sort of headset to convert the signal to audio, which was always very weak and just a simple click or buzz at best.<\/p>\n

Because these systems provided no gain on the receiving end, range was determined by the amount of transmitted power, the quality of the receiver, the experience of the operator to adjust it, and, of course, atmospheric conditions. What Marconi realized was that given a reasonably predictable range, a network of stations could be built to reliably communicate information across both continents and oceans. This included installations both on land and at sea.<\/p>\n

Marconi set off to install his wireless stations across the globe and at sea, both on passenger ships and cargo ships.[…]<\/p><\/blockquote>\n

Click here to continue reading the full article at Microwaves and RF.<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

(Source: Microwaves and RF) A Selected History of Receiver Innovations Over the Last 100 Years by\u00a0Brad Brannon This article, the first of a two-part series on receiver technology, looks at the genesis and early advances of this all-important area. Many contributed to the early days of wireless, but it\u2019s safe to say that Guglielmo Marconi […]<\/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],"tags":[7534,4091,681],"class_list":["post-35584","post","type-post","status-publish","format-standard","hentry","category-news","category-radio-history","tag-microwaves-and-rf","tag-radio-history","tag-vintage-radio"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-9fW","jetpack-related-posts":[{"id":28246,"url":"https:\/\/swling.com\/blog\/2017\/09\/cross-country-wireless-release-sdr-4-special-edition-sdr-receiver\/","url_meta":{"origin":35584,"position":0},"title":"Cross Country Wireless release SDR-4+ Special Edition SDR receiver","author":"Thomas","date":"September 11, 2017","format":false,"excerpt":"(Source: Southgate ARC and Kim Elliott) Cross Country Wireless have released a Special Edition version of their\u00a0SDR-4+receiver. This includes many features previously only available in custom versions of the receiver. Adding a high IP3 push pull RF amplifier, RF filter upgrades and a lower noise and distortion IQ amplifier have\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\/2017\/09\/Cross-Country-Wireless-SDR.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":8719,"url":"https:\/\/swling.com\/blog\/2014\/02\/cross-country-wireless-introduces-an-hf-upconverter\/","url_meta":{"origin":35584,"position":1},"title":"Cross Country Wireless introduces an HF Upconverter","author":"Thomas","date":"February 3, 2014","format":false,"excerpt":"(Source: Southgate ARC) Cross Country Wireless have just released a HF Upconverter. This will allow HF or VHF SDR receivers such as the RTLSDR dongles, Funcube or our own SDR-4+ receiver to work on HF, LF and VLF. Unlike other upconverters currently available we have added the RF protection features\u2026","rel":"","context":"In "AM"","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"The CCW HF Upconverter (Photo: Cross Country Wireless)","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/02\/hf_upconverter_medium-300x192.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":37370,"url":"https:\/\/swling.com\/blog\/2019\/05\/rsgb-2018-convention-lecture-dc-to-microwaves-on-your-smartphone\/","url_meta":{"origin":35584,"position":2},"title":"RSGB 2018 Convention Lecture: DC to Microwaves on your smartphone","author":"Thomas","date":"May 18, 2019","format":false,"excerpt":"(Source: Southgate ARC) The presentation by\u00a0Noel Matthews G8GTZ on the Farnham WebSDR given to the 2018 RSGB Convention is now available on YouTube: https:\/\/youtu.be\/uwteQsmLVFs Click here to view on YouTube. This presentation gives an overview of the Farnham WebSDR, available at\u00a0http:\/\/farnham-sdr.com\/\u00a0which currently covers the LF bands through to 10GHz. 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\/2019\/05\/Screen-Shot-2019-05-12-at-7.11.27-AM.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/05\/Screen-Shot-2019-05-12-at-7.11.27-AM.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/05\/Screen-Shot-2019-05-12-at-7.11.27-AM.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/05\/Screen-Shot-2019-05-12-at-7.11.27-AM.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":2296,"url":"https:\/\/swling.com\/blog\/2011\/12\/silabs-brings-shortwave-to-car-radios\/","url_meta":{"origin":35584,"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":47187,"url":"https:\/\/swling.com\/blog\/2021\/01\/dans-thoughts-on-a-panasonic-rf-9000-up-for-auction\/","url_meta":{"origin":35584,"position":4},"title":"Dan’s thoughts on a Panasonic RF-9000 up for auction","author":"Thomas","date":"January 6, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Robinson, who writes: Appearing on the Japanese Buyee website is this RF-9000, which was the \"King of Radios\" of the heavy multiband \"portable\" era. In recent years, RF-9000s in excellent to LNIB condition have sold for $10,000 or more. A tour d'force of\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/01\/Panasonic-RF-9000-e1609933467525.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/01\/Panasonic-RF-9000-e1609933467525.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/01\/Panasonic-RF-9000-e1609933467525.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/01\/Panasonic-RF-9000-e1609933467525.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":14989,"url":"https:\/\/swling.com\/blog\/2015\/10\/aircraft-communications-in-1915\/","url_meta":{"origin":35584,"position":5},"title":"Aircraft Communications in 1915","author":"Thomas","date":"October 2, 2015","format":false,"excerpt":"Many thanks to SWLing Post reader, Robert Gulley, who notes the following on his blog: I found this interesting post from Scientific American concerning the lack of reliable wireless communication in aircraft in 1915 \u2013 just one of those fascinating historical tidbits. You can read the full post on Robert's\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"A French communication system for use by airplane pilots in 1915: black powder could be puffed out into a Morse code message. Image: Scientific American, September 25, 1915 ","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/10\/MorseCodeAir-264x300.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\/35584","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=35584"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/35584\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=35584"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=35584"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=35584"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}