{"id":6216,"date":"2018-02-01T04:49:07","date_gmt":"2018-02-01T10:49:07","guid":{"rendered":"http:\/\/w0ep.us\/OM\/?p=6216"},"modified":"2018-02-01T04:50:33","modified_gmt":"2018-02-01T10:50:33","slug":"goodies","status":"publish","type":"post","link":"http:\/\/w0ep.us\/OM\/?p=6216","title":{"rendered":"Goodies"},"content":{"rendered":"<p>[Today&#8217;s run: 3.5 miles]<\/p>\n<p>I&#8217;ve taken apart a few of my new acquisitions and I have some interesting pieces.<\/p>\n<p><a href=\"http:\/\/w0ep.us\/OM\/?attachment_id=6217\" rel=\"attachment wp-att-6217\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-6217 aligncenter\" src=\"http:\/\/w0ep.us\/OM\/wp-content\/uploads\/2018\/01\/IMG_20180131_195551193-700x525.jpg\" alt=\"\" width=\"700\" height=\"525\" srcset=\"http:\/\/w0ep.us\/OM\/wp-content\/uploads\/2018\/01\/IMG_20180131_195551193-700x525.jpg 700w, http:\/\/w0ep.us\/OM\/wp-content\/uploads\/2018\/01\/IMG_20180131_195551193-768x576.jpg 768w, http:\/\/w0ep.us\/OM\/wp-content\/uploads\/2018\/01\/IMG_20180131_195551193-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/a><\/p>\n<p>Most knobs that I run into use a 1\/4 inch shaft.\u00a0 Then they usually have one or two set screws, either allen head or flat-head set screws.\u00a0 I have added to my stock more of that type. \u00a0 These other knobs instead have a plastic cover to pry off.\u00a0 Under that is a nut which operates a wedging &#8220;cap&#8221;.\u00a0The knob itself is lined with a brass tubing.\u00a0 \u00a0 The cap goes on the shaft and squeezes from all sides as it is drawn up by the nut.\u00a0\u00a0 Pretty fancy stuff.<\/p>\n<p><iframe loading=\"lazy\" title=\"salvage: potentiometer and reduction drive\" width=\"580\" height=\"326\" src=\"https:\/\/www.youtube.com\/embed\/K-kx7Poxkmo?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>And I&#8217;ve run into a handful of these peculiar vernier reduction drive mechanisms. Most that I run into have a 6:1 reduction. These guys seem to have something closer to 25:1. The knob will turn 270+ degrees (not quite a full circle). But the potentiometer on the other side of the reduction drive only turns a little bit. The example I&#8217;m showing in this little video is a 20,000 Ohm potentiometer. The portion covered by the motion of the knob is only 700 Ohms. I&#8217;m not sure why they built it this way instead of using a 1,000 potentiometer and a directly-connected knob.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>[Today&#8217;s run: 3.5 miles] I&#8217;ve taken apart a few of my new acquisitions and I have some interesting pieces. Most knobs that I run into use a 1\/4 inch shaft.\u00a0 Then they usually have one or two set screws, either allen head or flat-head set screws.\u00a0 I have added to my stock more of that [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,1],"tags":[],"class_list":["post-6216","post","type-post","status-publish","format-standard","hentry","category-ham-radio","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/6216","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6216"}],"version-history":[{"count":3,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/6216\/revisions"}],"predecessor-version":[{"id":6220,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/6216\/revisions\/6220"}],"wp:attachment":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6216"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6216"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}