{"id":3243,"date":"2017-07-30T17:26:41","date_gmt":"2017-07-30T15:26:41","guid":{"rendered":"http:\/\/www.retro.co.za\/blog\/?p=3243"},"modified":"2017-07-31T09:28:20","modified_gmt":"2017-07-31T07:28:20","slug":"swr-meter-rebuild","status":"publish","type":"post","link":"http:\/\/www.retro.co.za\/blog\/?p=3243","title":{"rendered":"SWR Meter rebuild"},"content":{"rendered":"

From a bunch of stuff some other ham wanted to throw away, this ex-SWR meter.<\/p>\n

\"Stripped\"<\/p>\n

I have no idea why the Dreaded Previous Owner stripped it down to this state. The meter movement is fine, 950-ish mV over a 4k7 resistor<\/a> gives FSD, so it’s a 200uA unit.<\/p>\n

\"inside\"<\/p>\n

The detector components are still in place, and it looks very similar to the Micronta 21-520A<\/a> except that there’s only one meter. There’s also a little bobbin on the side for an antenna, presumably to make it into a Field-Strength Meter<\/a>, but that’s a gimmick and won’t happen.<\/p>\n

\"NewSwitches\"<\/p>\n

The junkbox<\/a> yielded two switches of the right type and size (one selects Power \/ SWR, and in SWR mode the other selects Forward \/ Reverse). There will also be a pot to set FSD in Forward mode after which the Reverse mode should give the SWR. Give or take. Don’t expect a lot from meters like this.<\/p>\n

Fast forward a bit and we have<\/p>\n

\"IMG_0070r\"<\/p>\n

\"IMG_0068r\"<\/p>\n

Don’t ask me what used to live in those two extra holes. This setup works for me, for the price of a few junkbox parts and some time.<\/p>\n

 

From a bunch of stuff some other ham wanted to throw away, this ex-SWR meter. I have no idea why the Dreaded Previous Owner stripped it down to this state. The meter movement is fine, 950-ish mV over a 4k7 resistor gives FSD, so it’s a 200uA unit. The detector components are still in place, and it looks very similar to the Micronta 21-520A except that there’s only one meter. There’s also a little bobbin on the side for an antenna, presumably to make it into a Field-Strength Meter, but that’s a gimmick and won’t happen. The junkbox yielded two...<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[75,81,84],"tags":[],"class_list":["post-3243","post","type-post","status-publish","format-standard","hentry","category-electronics","category-radio","category-zs1ke"],"_links":{"self":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3243"}],"version-history":[{"count":4,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3243\/revisions"}],"predecessor-version":[{"id":3770,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3243\/revisions\/3770"}],"wp:attachment":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3243"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}