{"id":2967,"date":"2024-03-25T11:57:17","date_gmt":"2024-03-25T11:57:17","guid":{"rendered":"https:\/\/m0aws.co.uk\/?p=2967"},"modified":"2024-03-25T12:04:14","modified_gmt":"2024-03-25T12:04:14","slug":"more-868mhz-antenna-tests","status":"publish","type":"post","link":"https:\/\/m0aws.co.uk\/?p=2967","title":{"rendered":"More 868Mhz Antenna Tests"},"content":{"rendered":"\n

After initially finding that I couldn’t tune the 868Mhz ground plane antenna with the radials bent down at 45 degrees I decided to experiment to find out why. <\/p>\n\n\n\n

Initially I had the radials connected to the 4 corners of the base of the chassis mount N Type socket. This works great if you have the radials completely horizontal and gives an SWR of 1.1:1 but, with the radials bent down at 45 degrees the best SWR is around 2:1.<\/p>\n\n\n\n

\"M0AWS
M0AWS 868Mhz Ground Plane Antenna Close Up<\/figcaption><\/figure>\n\n\n\n

Removing the radials from the base of the N Type chassis socket and soldering them to the outer of the N Type plug at the same level as the feed point for the radiating element I found that an almost perfect SWR can be achieved very easily.<\/p>\n\n\n\n

\"M0AWS
M0AWS 868Mhz Antenna with radials soldered to the N Type Plug<\/figcaption><\/figure>\n\n\n\n

It seemed weird to me that such a small change could have such a big effect on the obtainable SWR for the antenna but, as can be seen in the image below with the radials soldered to the N Type plug and bent downwards I immediately got an SWR of 1.07:1 and a much wider SWR curve.<\/p>\n\n\n\n

\"M0AWS
M0AWS 868Mhz Antenna SWR curve with radials soldered to N Type plug.<\/figcaption><\/figure>\n\n\n\n

By making my own antennas I’m learning a lot about antenna design for the 800-900Mhz frequency range. Minor changes seem to have a much bigger impact than they do at much lower frequencies.<\/p>\n\n\n\n

More soon …<\/p>\n","protected":false},"excerpt":{"rendered":"

After initially finding that I couldn’t tune the 868Mhz ground plane antenna with the radials bent down at 45 degrees I decided to experiment to find out why. Initially I had the radials connected to the 4 corners of the base of the chassis mount N Type socket. This works great if you have the … <\/p>\n

Continue reading “More 868Mhz Antenna Tests”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[276,225,6,28,294,4,65,224,272,186,130,232,233,17],"tags":[],"class_list":["post-2967","post","type-post","status-publish","format-standard","hentry","category-868mhz","category-analyser","category-antenna","category-antenna-modelling","category-antennadesign","category-ham-radio","category-home-brew","category-jncradio","category-meshtastic","category-nodes","category-qrpp","category-vna","category-vna-3g","category-weak-signals"],"_links":{"self":[{"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/2967","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2967"}],"version-history":[{"count":9,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/2967\/revisions"}],"predecessor-version":[{"id":2979,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/2967\/revisions\/2979"}],"wp:attachment":[{"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m0aws.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}