{"id":889,"date":"2011-06-12T21:25:29","date_gmt":"2011-06-13T02:25:29","guid":{"rendered":"http:\/\/w0ep.us\/OM\/?p=889"},"modified":"2011-06-13T16:07:57","modified_gmt":"2011-06-13T21:07:57","slug":"rotator-control","status":"publish","type":"post","link":"http:\/\/w0ep.us\/OM\/?p=889","title":{"rendered":"Rotator control"},"content":{"rendered":"

[Today’s run: none]<\/p>\n

One of the benefits of having a tower is that, for bands with shorter\/smaller wavelengths, I can use directional antennas. \u00a0That means that the radiated energy goes more toward one direction than another. \u00a0You can point it.<\/p>\n

But to do the pointing you have to have some kind of motor that does the moving. \u00a0My system has a rotator that will turn my antennas relative to the points of the compass (azimuth). \u00a0I do not have any mechanism for moving “up and down” in elevation. \u00a0(If I were tracking a satellite or the moon I would want to be able to do that. \u00a0But I’m not.)<\/p>\n

Why only those antennas for smaller wavelengths? \u00a0Because longer wavelengths mean larger antennas. \u00a0Shorter wavelengths mean smaller antennas and more pointable antennas. \u00a0As frequency goes up the wavelength gets shorter. \u00a0So for higher frequencies you have smaller antennas. \u00a0(Which is why your cell phone uses a very high frequency.)<\/p>\n

I have a set of wires that run from the house to the rotator on top of the tower. \u00a0They carry electrical power to the motor and they also carry sensing information to tell me which direction my antenna is pointing.<\/p>\n

This picture is of the control box. \u00a0There is an on\/off switch, a calibration knob (only used at the beginning to get N to be north.) \u00a0and three buttons. \u00a0The middle button releases a mechanical brake. \u00a0The other two are to move the motor clockwise or counter-clockwise. \u00a0To operate you hold down the brake button while also pushing a motor-direction button. \u00a0Release the motor button while still holding down the brake release. \u00a0After 4-5 seconds you can then release the brake button, which sets the brake again.<\/p>\n

And there is a meter which is used to tell me which way my antenna is pointing. \u00a0As you can see, to get from SE to SW I have to go all the way around via N. \u00a0I cannot go past S. \u00a0My rotor probably could be made to do it, but my antenna feed wires would eventually wrap around the mast and make a mess. \u00a0So they make the rotor only go so far.<\/p>\n

(and yes, I need to get a camera with a close focus ability…)<\/p>\n

\"\"<\/a><\/p>\n

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

[Today’s run: none] One of the benefits of having a tower is that, for bands with shorter\/smaller wavelengths, I can use directional antennas. \u00a0That means that the radiated energy goes more toward one direction than another. \u00a0You can point it. But to do the pointing you have to have some kind of motor that does […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-889","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/889","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=889"}],"version-history":[{"count":4,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/889\/revisions"}],"predecessor-version":[{"id":894,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/889\/revisions\/894"}],"wp:attachment":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=889"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}