I once worked for Radio Service Company, the Motorola two-way radio shop in Lincoln, Neb. It had several repeater systems around the area, and at least one was installed on KOLN-TV's tower near Beaver Crossing. This was when there was an equipment shed mounted on the tower around 1,200 feet off the ground, gone now due to removing some of the load from the tower for DTV conversion.
Access was via a 20-minute elevator ride up the middle of the tower so we didn't have to climb it. Occasionally, the shop would get complaints from customers to the west that their radios didn't work. No complaints from the north, south, or east, however.
Since I was the new guy, I was asked to go look at it. Of course, the radio was good, and the SWR on the antenna was good, just as I was told to expect. The next thing I did was to take the elevator to where the antenna was and look at it. The antenna was fixed to an 8-inch triangular tower section mounted horizontally so that the vertical antenna was about 10 feet from the TV tower.
Two of the triangular tower section legs had broken about three feet back from the antenna mount. The slightest amount of wind from the west would cause the antenna to lean to the east. The coax lines for that and other low-gain antennas ran along one of the broken legs and limited the amount of twist in the tower section. Due to the narrow beam of the high-gain antenna, the customers to the west lost coverage when it leaned. After the shop's tower crew repaired the mount, all was well in the west again.
This entry was submitted by Stephen Wimmer and edited by Rob Spiegel.
Stephen Wimmer has held an amateur radio license since 1968 and a commercial radio license since 1970. He served in the US Navy for six years as a communication technician, and since then he has worked as an antenna design technician, a radio service technician, and currently as an electronic design technician for Bosch Security Systems in Lincoln, Neb.
Tell us your experience in solving a knotty engineering problem. Send stories to Rob Spiegel for Sherlock Ohms.
Sounds like "new guy" here means last hired, not inexperienced. And I would not apply for that job either. I didn't know how bad my vertigo was until I had to test it driving a 4-wheel drive stickshift big-tire pickup (all for the first time) down a mountain "road"--more like a wide deerpath--from near the top of the continental divide to about 1500 feet below. It was the tennis-racket-shaped hairpin loop with 1,000-foot drops on 3 sides that did me in.
At 1200 feet, I suspect there's a delicate balance between strngth and weight. Also, given the region (nebraska), it's pretty hard to design for the strongest potential winds (it IS tornado area). A wild straightline gust, or rotation that doesn't reach the ground would damage anything in its way. Putting a shack up there adds to the wind load...
Nancy Golden; Sort of like when the 'stuff' flows downhill. I have been the 'new' guy that was handed the problem a few times. In my experience, sometimes the 'senior' techs, (sometimes by tenure at a company vs. actual practical experience), will make a quick decision that the problem does not warrant their attention. That could be because it is percieved as a simple problem, or an unimportant problem. And that could be linked back to the 'assume' comment from another post. Since troubleshooting always begins with some assumptions, my take on that is to 'Know your assumptions, and know when to re-visit them'. And the culture is usually that the senior techs have the most 'valid' assumptions. Many times they do - occasionally they don't.
I see you what you are saying GlennA. Test engineering in the semiconductor industry is rather tame compared to other areas of electronics such as the one under discussion - so the decision to send someone to fix something like a test set is not physically demanding or uncomfortable - the pressure is mostly mental (Can the guy fix it - and if it's a production tester - can he fix it really fast because we are losing money). As test engineering manager, rather than sending the "new guy," I would evaluate the situation. If it was "hot" a senior (meaning experienced) tech would be asked to take care of it. A "new" (meaning inexperienced) guy might be sent along to learn. If not "hot," depending on the newbie's ability, I might ask him to take care of a problem so that he can gain both experience and confidence, knowing we have senior techs to back him up if needed...sounds like a very different work culture - each one growing partially due to the physical environment that they are operating in.
Nancy, where it may cost $250 an hour just to OWN a fully operating semiconductor tester... and thousands more in product that's not processed, the pressure to get the tester or test handler back online is substantial.
Having paid for college in the broadcast industry, I can relate to Glenn's experience aloft. "If it ain't broke, don't fix it" often translates to "if it ain't reducing revenue, why bother?".
When the wind blows from the west, we lose the signal in that direction? Yeah, sure. Tell me another one. Particularly if the station had contract people doing tower maintenance, the urge to wait for the next inspection, rather than go up 1200' would be awfully strong.
Plus, the cracked legs on the standoff-section of tower might not have been visible unless the wind was right.
They were lucky the thing didn't get ripped off the tower.
Good story, though, Glenn! See you on the radio! de N2EA
ab3a- I just could_not_climb a tower, young or old. Kudos to those who do, it is necessary. I watched a video of a tower climb on YouTube; amazing how much sweating vertigo induces.
streetrodder- I once worked on a design for an island to island radio system in the Caribbean, pretty hard to design for Cat 4/5 hurricane winds, just like tornado alley.
I have not climbed the big towers. I've been up towers to the 300 foot level.
I usually had the luxury of choosing when to climb and I usually take a water bottle and a snack with me.
You never know what you'll find when you climb, so stay in shape and be prepared to get off the ladder.
I've been on the side of the tower on step bolts too.
That was 20 years ago. I don't think I can do so well today...
Jake Brodsky
Since I get nervous on a step ladder, I am glad there are people like the author willing to do the high wire stuff. Oh yeah, we just had some trees trimmed around our lake house and imagine or surprise when we now have 7 over the air channels instead of 2.
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