MEASURING \u00bc WAVE LINES<\/p>\n
Hams use quarter wave lines for many purposes, impedance matching, stub filtering, etc. There are several methods to cut these lines to the proper length. A method was described to me by K5GW which is simple and seems to be more accurate than others I have tried. It uses equipment which is present in nearly all ham shacks. If you have a dummy load, a T connector, an SWR meter, and your radio you can do it. <\/p>\n
1. Connect the T connector to your dummy load.
\n2. Connect your SWR meter to the T connector and to your transceiver through short lengths of coax.
\n3. Key the rig up and note the SWR, it should be 1 or very close to 1.
\n4. Connect the \u00bc wave line to the other side of the T connector.
\n5. Short the far end of the coax. I have been able to short it with a needle pushed thru the coax line.
\n6. Sweep the frequency until you see a SWR of 1.
\n7. Change the shorting point until the SWR=1 point is at the desired frequency.
\n8. Cut and short the coax at that point.<\/p>\n
Of course this method will work for any odd multiple of quarter wave line. It should also work to measure half wave lines with open rather than shorted ends but I have not tried that mode.<\/p>\n
73, Dan, N5AR<\/p>\n","protected":false},"excerpt":{"rendered":"
Quick and easy method<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-248","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/posts\/248","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/sdxa.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=248"}],"version-history":[{"count":1,"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/posts\/248\/revisions"}],"predecessor-version":[{"id":11273,"href":"https:\/\/sdxa.org\/index.php?rest_route=\/wp\/v2\/posts\/248\/revisions\/11273"}],"wp:attachment":[{"href":"https:\/\/sdxa.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=248"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sdxa.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=248"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sdxa.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=248"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}