{"id":2191,"date":"2011-01-19T11:52:30","date_gmt":"2011-01-19T15:52:30","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=3928"},"modified":"2023-09-23T09:29:51","modified_gmt":"2023-09-23T13:29:51","slug":"center-of-box-amc-8","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2011\/01\/center-of-box-amc-8\/","title":{"rendered":"Center of Box, AMC-8"},"content":{"rendered":"\n

Satellite dishes have been a part of radio station technical equipment for years. I am surprised at the number of broadcast engineers that do not consider center of box when aiming dishes. As dishes get larger and focal points get smaller, center of box aiming is not a nice thing to do, it is a necessary thing to do.  The latest generation of satellite receivers, (AKA XDS) have a somewhat less than lively RF front end, they require higher E\/B than the previous generation Starguide receivers to stay locked.<\/p>\n\n\n\n

For years, the majority of commercial radio networks were carried on AMC-8 or its predecessors living at 139\u00b0\u00a0W. \u00a0On the East Coast, particularly in the Northeast, that makes aiming points relatively low to the horizon, anywhere between 8-10\u00b0\u00a0elevation.<\/p>\n\n\n\n

\"3.2<\/a>
3.2 meter COMTECH satellite dish<\/figcaption><\/figure>\n\n\n\n

This all means that precise aiming the satellite receive dish is critical for satisfactory performance. SES Americom owns AMC-8 and thus they have a web page about all of their satellites and important operating information. SES Center of box for AMC-8<\/a> is available in one-month blocks, which makes scheduling the aiming chore fairly easy.<\/p>\n\n\n

\n
\"Large<\/a>
Large satellite dish aiming diagram<\/figcaption><\/figure>\n<\/div>\n\n\n

I have always used a spectrum analyzer through a 3 dB splitter to look at the 950 MHz \u00a0LNB output. \u00a0This aiming setup allows the best combination of Azimuth\/Elevation\/polarization. \u00a0Using the satellite receiver to confirm and maintain signal lock, peak the waveform that the \u00a0receiver is locked to. \u00a0It is pretty crowded up there, so there will be lots of signals on the spectrum analyzer trace.<\/p>\n\n\n\n

It is a pain in the rear end to lug all that equipment out to the satellite dish, especially if it is on the roof.  That is why it only need be done once; the right way the first time.<\/p>\n\n\n\n

Any shortcuts will likely lead to those annoying chirps and dropouts or complete loss programming, particularly when the weather turns bad.<\/p>\n","protected":false},"excerpt":{"rendered":"

Satellite dishes have been a part of radio station technical equipment for years. I am surprised at the number of broadcast engineers that do not consider center of box when aiming dishes. As dishes get larger and focal points get smaller, center of box aiming is not a nice thing to do, it is a … Continue reading Center of Box, AMC-8<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[131],"class_list":["post-2191","post","type-post","status-publish","format-standard","hentry","category-tech-stuff","tag-satellite"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/2191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/comments?post=2191"}],"version-history":[{"count":6,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/2191\/revisions"}],"predecessor-version":[{"id":12454,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/2191\/revisions\/12454"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=2191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=2191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=2191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}