In order to find out the extent to which the dipoles for 30 and 40m affected the performance of the tribander, a FB-53, a number of measurements were performed. These were carried out in October 2014, and were limited mainly to the 20-meter band. The dipole was mounted about 50 cm below the tribander.<\/p>\n
To perform the test I was using a reference dipole a few meters at the side of the beam when beaming North America and also a reference station with which there had been several measurement series over the years comparing the FB-53 Yagi with another tribander. On the average the FB-53 has been 2 dBs better than the other tribander towards North America during afternoons.<\/p>\n
The comparisons were made by extensive number of Reverse Beacon spots from the North American East coast and averaging a large number.<\/p>\n
The results can be summarized as follows: With the 30\/40m dipoles along the radiator of the tribander and the coax from the dipole tuned at the lower end with a capacitor for SWR=1 on 20m<\/u><\/strong><\/p>\n 1. -3 dB compared with the reference dipole.(1 dB worse than shorted coax). With the 30\/40m dipoles along the radiator of the tribander and the coax from the dipole connected to a 50 ohm dummy load at the lower end.<\/u><\/strong> With the 30\/40m dipoles along the boom of the tribander<\/u><\/strong><\/p>\n Conclusion<\/u><\/strong><\/p>\n The proximity of the 30\/40m dipoles to the tribander severely deteriorates the performance of the FB-53.<\/p>\n A second finding is that the gain of the FB-53 is 3 dBd on 20 m.<\/strong><\/p>\n \u00a0<\/u><\/strong><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" In order to find out the extent to which the dipoles for 30 and 40m affected the performance of the tribander, a FB-53, a number of measurements were performed. These were carried out in October 2014, and were limited mainly to the 20-meter band. The dipole was mounted about 50 cm below the tribander. To […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[],"class_list":["post-701","post","type-post","status-publish","format-standard","hentry","category-okategoriserade-en"],"_links":{"self":[{"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/posts\/701","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=701"}],"version-history":[{"count":6,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/posts\/701\/revisions"}],"predecessor-version":[{"id":1041,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=\/wp\/v2\/posts\/701\/revisions\/1041"}],"wp:attachment":[{"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=701"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=701"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sm0brf.se\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=701"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nWith the 30\/40m dipoles along the radiator of the tribander and the coax from the dipole shorted at the lower end<\/u><\/strong><\/p>\n\n
\n(It was possible to change the F \/ B ratio by shifting between the capacitor and short circuiting.)<\/p>\n
\n13% of the power fed to the tribander was dumped in the dummy load.<\/p>\n\n
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