{"id":9128,"date":"2016-07-22T18:17:45","date_gmt":"2016-07-22T22:17:45","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=9128"},"modified":"2023-03-19T12:02:30","modified_gmt":"2023-03-19T16:02:30","slug":"the-horns-of-a-dilemma","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2016\/07\/the-horns-of-a-dilemma\/","title":{"rendered":"The Horns of a Dilemma"},"content":{"rendered":"

Alternate title: Building and ATU in a truck body toolbox.<\/p>\n

Alternate title II: I should get paid extra for this shit.<\/p>\n

There is an AM radio station that is near death but the owners do not want it to go away.\u00a0 Nor do they want to spend very much money to keep it around, thus the dilemma.\u00a0 At the transmitter site, there is a multitude of problems; leaking roof, very old rusty ATU, rotting support posts and transmission line bridge, equipment racks rusting out, nothing is grounded properly, the building is full of junk, snakes, and mice have moved in.\u00a0 To further complicate things, the tower and transmitter building serves as an STL relay point for two of the market’s FM stations.\u00a0 There is also two translators with antennas on the tower.\u00a0 The ATU and tower light choke box are rusting through, which is causing arcing and broadband RF noise that is interfering with the FM station’s STL receiver.\u00a0 There was a homemade isocoupler for one of the translators that were allowing AM RF back into the building which was creating havoc with everything.\u00a0 Because of this, the AM station is currently silent.\u00a0 In short, it is a mess.<\/p>\n

\"WCHN<\/a>
WCHN ATU<\/figcaption><\/figure>\n

The red box on the bottom is the ATU, the plywood box on the top with the peeling yellow paint is the homemade isocoupler, and the tower light choke box is behind the isocoupler.<\/p>\n

\"Crumbling<\/a>
Crumbling old ATU output capacitor in series with tower<\/figcaption><\/figure>\n

This was the capacitor that was feeding the antenna, .0041uf, 10KV 8 amps.<\/p>\n

We started remediation on this last February, which is not the optimum time for replacing rotting wooden posts.\u00a0 However, we were able to clean out the building.\u00a0 The leaking roof has been repaired.\u00a0 I was able to find a few old racks from a Schafer Automation<\/a> system to replace the rusted-out original racks.\u00a0 I began the process of grounding the equipment racks, the incoming transmission lines for the STL, etc.<\/p>\n

\"Cool<\/a>
Cool morning, Garter Snakes warming themselves on top of a Moseley DSP-6000<\/figcaption><\/figure>\n
\"Garter<\/a>
Garter Snake<\/figcaption><\/figure>\n

We will have to find out how they are getting in, the plug up those holes.<\/p>\n

Then there were the ATU and tower light choke enclosures.\u00a0 Original to the 1952 sign-on, they were past their serviceable days.\u00a0 Since this is all being done on a budget and nobody wants to spend money on an AM station that has little or no listeners and even less revenue, we had a problem.<\/p>\n

Then somebody suggested building an ATU in a truck body tool box<\/a>.\u00a0 Well…\u00a0 This isn’t the Meadowlands, so if there are no other alternatives then okay, I guess.\u00a0 Off to Amazon to order a toolbox.\u00a0 This particular unit seems fine, my only comment is on the gauge aluminum (or aluminium if you prefer), which is slightly thin for holding up all those parts.<\/p>\n

\"ATU<\/a>
Fabrication shop, ATU built in a truck body toolbox<\/figcaption><\/figure>\n

Still, the box itself is nice enough and certainly better than the old one.\u00a0 I was able to reuse the inductor and the Delta current meter but the old Sangamo capacitors crumbled in my hands when I removed them.\u00a0 I also saved the feed through bowls, J-plugs, and other parts.\u00a0 I used some copper strap to run a good RF ground from the input to the ground connection.\u00a0 Overall, I am pretty pleased with the finished product.\u00a0 It is a little bit tight in there, but this station only runs 1 KW, so it should be fine.<\/p>\n

\"Replacement<\/a>
Replacement ATU mounted<\/figcaption><\/figure>\n

So, new pressure-treated posts were installed, the box was mounted and the transmission line was connected.<\/p>\n

\"Replacement<\/a>
Replacement ATU under power.<\/figcaption><\/figure>\n
\"Reused<\/a>
Reused Schafer Automation racks, much better than the 1950’s Gates racks<\/figcaption><\/figure>\n

The reused racks are old but serviceable and a big improvement over the old, rusting-out racks.\u00a0 I was able to bond each rack to the ground strap that was used to connect to the RCA BTA-1 transmitter.\u00a0 There is one more rack to install to the right of these two.\u00a0 That should give us more than enough rack space for this site.<\/p>\n

The station is back on at full power and not interfering with the FM STLs or the translators.\u00a0 You can actually touch the rack and not get an RF burn!<\/p>\n

We are also working on an air conditioner.<\/p>\n

Other work at this site; cleaning out the building, replacing the tower light photocell, installing a ground buss bar, some STL lightning protectors, dressing the transmission lines, etc.\u00a0 It is a work in progress.<\/p>\n","protected":false},"excerpt":{"rendered":"

Alternate title: Building and ATU in a truck body toolbox. Alternate title II: I should get paid extra for this shit. There is an AM radio station that is near death but the owners do not want it to go away.\u00a0 Nor do they want to spend very much money to keep it around, thus … Continue reading The Horns of a Dilemma<\/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":[87,284],"class_list":["post-9128","post","type-post","status-publish","format-standard","hentry","category-tech-stuff","tag-am","tag-am-tower"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/9128","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=9128"}],"version-history":[{"count":10,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/9128\/revisions"}],"predecessor-version":[{"id":11119,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/9128\/revisions\/11119"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=9128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=9128"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=9128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}