{"id":1691,"date":"2014-12-19T11:34:25","date_gmt":"2014-12-19T11:34:25","guid":{"rendered":"http:\/\/blog.agm.me.uk\/blog\/?p=1691"},"modified":"2014-12-19T19:54:51","modified_gmt":"2014-12-19T19:54:51","slug":"433mhz-antenna-lengths","status":"publish","type":"post","link":"https:\/\/blog.agm.me.uk\/blog\/2014\/12\/433mhz-antenna-lengths.php","title":{"rendered":"433MHz Antenna Lengths"},"content":{"rendered":"<p>I use a\u00a0<a href=\"http:\/\/www.ebay.co.uk\/sch\/i.html?_nkw=433MHz+Transmitter+Module&amp;_sop=15\">cheap 433MHz transmitter modules<\/a>\u00a0often and every time I need to work out what antenna length I should use because I never write it down. This blog post is me writing it down. The length needs to be an harmonic of the wavelength. The wavelength is speed of light divided by the frequency, or 299,792,458 m\/s divided by 433,000,000, or 692.361334873 mm for short.<\/p>\n<p>So the acceptable lengths are&#8230;<br \/>\n<a href=\"http:\/\/blog.agm.me.uk\/blog\/files\/2014\/12\/P1100237.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-medium wp-image-1693\" src=\"http:\/\/blog.agm.me.uk\/blog\/files\/2014\/12\/P1100237-300x225.jpg\" alt=\"433MHz Transmitter Module\" width=\"300\" height=\"225\" srcset=\"https:\/\/blog.agm.me.uk\/blog\/files\/2014\/12\/P1100237-300x225.jpg 300w, https:\/\/blog.agm.me.uk\/blog\/files\/2014\/12\/P1100237.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<ul>\n<li>692.36 mm<\/li>\n<li>346.18 mm<\/li>\n<li>173.09 mm<\/li>\n<li>86.545 mm<\/li>\n<li>43.273 mm<\/li>\n<li>21.636 mm<\/li>\n<li>10.818 mm<\/li>\n<li>5.4091 mm<\/li>\n<li>2.7045 mm<\/li>\n<li>1.3523 mm<\/li>\n<li>0.6761 mm<\/li>\n<\/ul>\n<p>In reality I normally go for 87\u00a0mm, or 43 mm if I am tight for space\u00a0and don&#8217;t need a strong signal. I did once use a\u00a017.3 cm antenna and the\u00a0coverage was amazing.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I use a\u00a0cheap 433MHz transmitter modules\u00a0often and every time I need to work out what antenna length I should use because I never write it down. This blog post is me writing it down. The length needs to be an harmonic of the wavelength. The wavelength is speed of light divided by the frequency, or [&hellip;]<\/p>\n","protected":false},"author":2,"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":[1],"tags":[],"class_list":["post-1691","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p4t60H-rh","_links":{"self":[{"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1691","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/comments?post=1691"}],"version-history":[{"count":8,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1691\/revisions"}],"predecessor-version":[{"id":1701,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1691\/revisions\/1701"}],"wp:attachment":[{"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/media?parent=1691"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/categories?post=1691"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.agm.me.uk\/blog\/wp-json\/wp\/v2\/tags?post=1691"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}