We included some comments recently from Jon Bennett on a rise in copper theft stations in Richmond, Va. Jon is a retired Cox market chief, now doing contract work in that area.
One of his clients, WGGM(AM) in Chester, has had two incidents of copper theft within the last year. The first required the station to replace the ground screen surrounding the tower, including ground strap and the copper feed line to the tower. After that, they poured additional gravel over the ground screen, to complicate the job of anyone trying to pull up that portion of the ground system.
In the second incident, a thief cut out the ground strap as it crossed under the base insulator and removed the exposed ground strap.
The station’s consulting engineer, Stu Graham of Graham-Brock, sent me Jon’s latest anti-theft approach. Stu writes that the solution is unique and believes the technique can help other stations.
As you can see beginning in Fig. 1, Jon has coated the base pier with tar. Not only does this protect the ground strap and connections from the weather and unintended damage; it also makes access by thieves much more difficult. Because the copper is not exposed, it is not as desirable to recycling centers.
Left to right: Fig. 1: Coat the base pier with tar to discourage copper theft; Fig. 2: The tar can be applied easily using a trowel; Fig. 3: A closeup of the top of the pier. The tar greatly reduces salvage value of the copper.
The tub of tar is cheap insurance when compared to replacing a ground system. You can apply it easily with a trowel.
The Graham-Brock website, www.grahambrock.com, is a good source of engineering techniques. Be sure to bookmark it.
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Fig. 4: Conduit at the transmitter site should be plugged. Expandable foam is used here. If your transmitter or rooftop studio site uses plastic conduit for cabling to towers or satellite dishes, make sure the ends are plugged, as seen in Fig. 4.
Water entering the open ends can freeze and split the conduit or route water into your equipment room. The openings also can attract snakes or rodents, regardless of whether the conduit is made of plastic or metal.
Any major hardware store can provide a range of sealing products. If you go with expandable foam, try plugging the opening with stainless steel or copper wool first, then seal. Animals that call your conduit home won’t chew through the metal wool and will be repelled.
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The recent Broadcasters Clinic in Wisconsin drew more than 300 registrants. It was an excellent time to network with fellow engineers and listen to top-notch technological presentations.
Fig. 5: Keep your tower site in check. A convenient list from consulting firm Munn-Reese can help. At the event I spoke with Ed Trombley, one of the consulting engineers at the firm Munn-Reese Inc. in Coldwater, Mich. He handed me a unique business card, about the size of a 3-by-5 index card. All of the company’s contact information is printed on one side. Flip it over and there’s a form titled “Been to the Tower Lately?” It contains 11 parameters or checks that should be performed quarterly. There are checkboxes for the months of January, April, July and October.
At a glance, you can ensure that your quarterly tower and other inspections have been completed.
In addition, there are 11 checks that should be performed at the transmitter site to keep you legal with the FCC and in keeping with good engineering practice.
This is a great way to start a regular maintenance plan, if you don’t have one. If you are an IT engineer who recently has been tasked with transmitter responsibilities as well, this maintenance checklist card will be invaluable.
For a free copy, send a self-addressed, stamped business-sized envelope to Ed Trombley, Engineer, Munn-Reese Inc., P. O. Box 220, Coldwater, MI 49036.
For more topical engineering information, visit the company’s website, www.munn-reese.com.
John Bisset marked his 40th year in radio in broadcasting recently. He now works with Tieline Technology. He is a past recipient of the SBE’s Educator of the Year Award. Reach him at [email protected]. He can be reached at (603) 472-5282. Faxed submissions can be sent to (603) 472-4944.
Submissions for this column are encouraged and qualify for SBE recertification credit.