{"id":3340,"date":"2012-07-24T07:19:25","date_gmt":"2012-07-24T14:19:25","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=3340"},"modified":"2012-09-12T21:28:53","modified_gmt":"2012-09-13T04:28:53","slug":"2012-07-24","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=3340","title":{"rendered":"2012-07-24 Cat’s Whisker Detector for a Crystal Radio"},"content":{"rendered":"

Whilte I was writing my blog about Homemade Components<\/a>, I visited the Wikipedia page about the cat’s whisker detector, the active component in the crystal radio.\u00a0 I read the intro paragraph<\/p>\n

“A cat\u2019s whisker detector<\/strong> (sometimes called a crystal detector<\/strong>) is an antique electronic component<\/a> consisting of a thin wire<\/a> that lightly touches a crystal of semiconducting<\/a> mineral (usually galena<\/a>) to make a crude point-contact rectifier<\/a>. Developed by early radio researchers Jagadish Chandra Bose<\/a>, G. W. Pickard<\/a> and others, this device was used as the detector<\/a> in early crystal radios<\/a>, from about 1906 through the Second World War<\/a>. It gave this type of radio receiver<\/a> its name. It was the first type of semiconductor diode<\/a>, and in fact the first semiconductor electronic device<\/a>. The term cat’s whisker was also sometimes used to describe the crystal receiver itself. Cat’s whisker detectors are obsolete and are now only used in antique or antique-reproduction radios.”<\/p><\/blockquote>\n

and several things struck me as being out of place.\u00a0 I’ll try to explain why I think these should be changed.\u00a0 I am pointing these out because I think they have insufficiencies, and I leave it up to the authors to decide whether or not they need to be changed.<\/p>\n

The wiki says “antique electronic component” which I think implies that all cat’s whisker detectors are very old.\u00a0 These are still being made for crystal radio enthusiasts and it is likely that if anyone sees a cat’s whisker detector, it will be a reproduction only a few years old, not an antique.\u00a0 I would say “an electronic component originally from the early days of radio” or something similar.<\/p>\n

They then go on to say “crude point-contact rectifier” which I think is an indication more of the author’s point of view today, rather than the actual situation when it was invented a century ago.\u00a0 I would say “.. was a better detector for its day, but was later superseded by much better detectors.”<\/p>\n

They then go on to make the claim that “..in fact it was the first semiconductor electronic device.”\u00a0 I think that one could argue that since carbon granules are neither conducting metal nor insulator, they are a semiconductor.\u00a0 Therefor the carbon granule microphone first invented by Thomas Edison was arguably the first semiconductor electronic device.<\/p>\n

One may also argue that the selenium photocell, the selenium rectifier, the copper oxide rectifier, are from the very early days of electricity and may predate the crystal detector as the earliest semiconductor electronic device.<\/p>\n","protected":false},"excerpt":{"rendered":"

Whilte I was writing my blog about Homemade Components, I visited the Wikipedia page about the cat’s whisker detector, the active component in the crystal radio.\u00a0 I read the intro paragraph “A cat\u2019s whisker detector (sometimes called a crystal detector) is an antique electronic component consisting of a thin wire that lightly touches a crystal <\/p>\n

(Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-3340","post","type-post","status-publish","format-standard","hentry","category-radio-frequency"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3340","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3340"}],"version-history":[{"count":11,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3340\/revisions"}],"predecessor-version":[{"id":4130,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3340\/revisions\/4130"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3340"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3340"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3340"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}