How to keep small radio system problems from becoming big problems
When I was a kid, there was a long-running television commercial for a brand of oil filters that had the tag line, “You can pay me now, or pay me later.” The message was clear: Keep up with regular maintenance such as oil changes to avoid a much more expensive repair bill down the road.
The message also rings true in land-mobile radio. In the current edition of Urgent Communications magazine, you will find an article that offers some excellent advice about tower upkeep. Last month, Jay Jacobsmeyer — a professional engineer and president of the Colorado Springs, Colo.-based consultancy Pericle Communications — offered his insights on tower maintenance and construction during a UC webinar sponsored by Cassidian Communications.
According to Jacobsmeyer, his firm found numerous instances of tower neglect during the lengthy process of reconfiguring the 800 MHz band.
“What we noticed was that systems during rebanding were getting scrutiny that they might not have gotten in a long time, and you find problems,” Jacobsmeyer said. “And all of these problems had gone unobserved by the users.”
Consequently, Jacobsmeyer recommended that tower owners put into place preventive maintenance programs that involve regular inspections and remote monitoring. One item that often gets overlook is the grouting that exists where the tower is bolted to the concrete foundation, according to Jacobsmeyer.
“If you let that grouting disintegrate, water will get underneath there and rust the bolts,” he said. “That’s a big deal, if that happens.”
Particular attention should be paid to the foundations of smaller towers, which often are erected using a simpler approach of burying rods into the ground and pouring concrete around the rods.
“Oftentimes, these things don’t have weep holes drilled into them. So what happens is, water gets into the legs, it freezes in the legs and it cracks the legs,” Jacobsmeyer said. “That’s a big deal, and you’d be surprised how often that happens.
Another common problem concerns tower foundations not being built up high enough, he said.
“So, the tower is surrounded by dirt, and that causes a lot of rust,” Jacobsmeyer said. “We’ve seen towers that were rusting away for 10, 15 years, and finally they crack right there at the base, and the tower has to be replaced — usually you can’t repair that kind of damage.”
But towers aren’t the only maintenance headache for a radio-system operator, Jacobsmeyer said.
“We see many cases where the mobile antenna on the cruiser, for example, is the type that is installed with an Allen screw to hold it in place — and by the way, we don’t recommend that approach,” he said. “The Allen screws come loose from vibration, and the antenna actually is missing. The police officer has been using that radio the entire time without the antenna, and they complain about coverage.”
Similar abuses befall portable antennas, Jacobsmeyer added.
“People often hang keys on them — the radio doesn’t work very well when you hang keys on the portable radio antenna,” he said. “But they also suffer damage internally, because they have been bent or dropped, and they don’t work as well as they should.”
Jacobsmeyer offered a few other useful tidbits during the webinar, which covered more ground than any such event we’ve produced in the eight years that we’ve been doing them. The event is archived on our website, and I urge you to tune in. I believe you’ll get a lot out of it. I know that I did.
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