{"id":7057,"date":"2013-07-27T09:38:45","date_gmt":"2013-07-27T13:38:45","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=7057"},"modified":"2023-03-30T08:32:26","modified_gmt":"2023-03-30T12:32:26","slug":"happiness-is-an-am-directional-array-at-licensed-values","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2013\/07\/happiness-is-an-am-directional-array-at-licensed-values\/","title":{"rendered":"Happiness is: An AM directional array at licensed values"},"content":{"rendered":"\n

Last week I did some repair work at WDDY<\/a> in Albany NY. It seems the sample line on one of the towers was melted in half by a lightning strike. This station uses sample loops up on the tower for its directional antenna monitoring system.<\/p>\n\n\n\n

\"WDDY<\/a>
WDDY antena array, Albany, NY<\/figcaption><\/figure>\n\n\n\n

As it happened, the sample line in question was on the reference tower, which makes everything else meaningless.\u00a0 Before the meltdown, there were several years’ worth of maintenance logs that showed the previous values for current ratio and phase relationship.<\/p>\n\n\n\n

With the transmitter turned off and locked out, I removed the damaged section of the line from the base of the tower to the RF choke coil in the tuning house.\u00a0 Where the sample line came off of the base of the tower, there was a UHF-type connector that had been improperly applied.\u00a0 Using spare parts, I fixed that connector, then spliced the line into place.\u00a0 Upon power-up, the transmitter and antenna readings returned to their previous values, which were slightly out of tolerance.<\/p>\n\n\n\n

Thus, some phasor tuning was needed.\u00a0 There are not too many people left that can properly tune an AM phasor.\u00a0 All of the control interact with each other; moving the power or phase to one tower will likely affect all of the other towers and possibly the reflected power on the transmitter.\u00a0 This phasor was made in the 1970s by Multronics with what looks like all RCA parts.\u00a0 Multronics, I think, was John Mullaney who is more known for the folded unipole antenna.\u00a0 In any case, after a good few hours of careful hand cranking and a run out to the reference tower to move a coil tap, here are the results:<\/p>\n\n\n\n

\"WDDY<\/a>
WDDY tower one, reference<\/figcaption><\/figure>\n\n\n\n
\"WDDY<\/a>
WDDY tower two<\/figcaption><\/figure>\n\n\n\n
\"WDDY<\/a>
WDDY tower three<\/figcaption><\/figure>\n\n\n\n
\"WDDY<\/a>
WDDY forward\/reflected power<\/figcaption><\/figure>\n\n\n\n

Not bad for a day’s work.<\/p>\n","protected":false},"excerpt":{"rendered":"

Last week I did some repair work at WDDY in Albany NY. It seems the sample line on one of the towers was melted in half by a lightning strike. This station uses sample loops up on the tower for its directional antenna monitoring system. As it happened, the sample line in question was on … Continue reading Happiness is: An AM directional array at licensed values<\/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":[87,33,18],"class_list":["post-7057","post","type-post","status-publish","format-standard","hentry","category-tech-stuff","tag-am","tag-am-towers","tag-am-transmitter-site"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7057","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=7057"}],"version-history":[{"count":4,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7057\/revisions"}],"predecessor-version":[{"id":11355,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7057\/revisions\/11355"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=7057"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=7057"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=7057"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}