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GlennA
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Gold
Visual inspection ?
GlennA   6/13/2012 10:50:29 AM
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How long had this problem been going on ?  It sounds like others had been tasked to find the cause prior to your visit.  Do you know how many techs had failed to notice the broken legs ?  Of course it is always best to investigate the problem while it is occuring, if possible.

S.Wimmer
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Iron
Re: Visual inspection ?
S.Wimmer   6/13/2012 12:55:31 PM
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I don't know how long that had been a problem.  I got the impression that it was just that spring.  This was one of those 'it can't happen' things that Mr. Agan's talks about in his book.  It also illustrates a couple of his points, 'understand the system' and 'quit thinking and look'.

Ann R. Thryft
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Blogger
Re: Visual inspection ?
Ann R. Thryft   6/14/2012 11:39:49 AM
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I like "quit thinking and look." A very pragmatic, practical, on-the-ground kind of troubleshooting. What book are you referring to?

Ann R. Thryft
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Blogger
Visual inspection beats all
Ann R. Thryft   6/13/2012 12:47:47 PM
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This is a great example of how a technical problem can be caused by something as simple as checking out the physical environment: broken tower legs + a strong directional wind = no coverage. It reminded me of the freight train that interfered with the cellphone signal.

Nancy Golden
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Platinum
Re: Visual inspection beats all
Nancy Golden   6/13/2012 5:38:00 PM
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I agree Ann - so many times people do everything except go and take a look...funny how the most obvious task is usually skipped as people look for more exotic reasons for a failure. It also speaks of the importance of environmental factors on equipment and that it should always be a design consideration whenever possible. Better to have more rugged tower legs in the first place...and avoid the problem completely.

Stephen
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Gold
Re: Visual inspection beats all
Stephen   6/14/2012 9:47:54 AM
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I'm guessing that prior techs didn't look at it up close because it was relatively inacessable -- being 1200' and 20min up the tower. Oops! 

Nancy Golden
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Platinum
Re: Visual inspection beats all
Nancy Golden   6/14/2012 10:37:24 AM
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Working for a radio service company so you know heights are involved and there is an elevator - I'm guessing the prior techs did not have much initiative...they sent the "new guy" when it seems more logical to send an experienced tech on that equipment with the new guy. I could be wrong but it looks more like a work culture issue than an inaccessibility issue...

ab3a
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Platinum
Re: Visual inspection beats all
ab3a   6/14/2012 11:06:14 AM
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Having climbed towers myself, let me assure you, this is not like an elevator ride in an office building.  There is still a lot of heart stopping climbing


Those who have been there, know all too well why the senior people don't like being up there.  This is definitely a task you give to the young.

 

Jake Brodsky

Nancy Golden
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Platinum
Re: Visual inspection beats all
Nancy Golden   6/14/2012 11:52:11 AM
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I apologize Jake -  I did not mean to imply it is a "walk in the park." My point was only that I would never apply for that type of job because if going up that tower was in the job description - I would be scared to death! But visual inspections are important and a part of any technical job. I guess I am thinking that different people have different personalities and heart stopping heights are a part of that field so it is something people in that field do. As far as seniors - of course I agree. But again, that is a work culture - youngsters doing that type of work is traditional and should be. Seniors have earned a pass. But experience does not necessarily mean senior - No offense intended!

notarboca
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Gold
Re: Visual inspection beats all
notarboca   6/19/2012 9:06:05 PM
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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.

ab3a
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Platinum
Re: Visual inspection beats all
ab3a   6/19/2012 9:13:16 PM
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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

S.Wimmer
User Rank
Iron
Re: Visual inspection beats all
S.Wimmer   6/14/2012 12:10:31 PM
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I was the 'new guy' at that shop.

By that time I had 10+ years experience under my belt, terrestrial and shipboard.

Ann R. Thryft
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Re: Visual inspection beats all
Ann R. Thryft   6/14/2012 1:35:56 PM
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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.

GlennA
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Gold
Re: Visual inspection beats all
GlennA   6/18/2012 10:18:34 AM
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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.

Nancy Golden
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Platinum
Re: Visual inspection beats all
Nancy Golden   6/18/2012 4:15:37 PM
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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.

jljarvis
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Gold
Re: Visual inspection beats all
jljarvis   6/19/2012 4:14:39 PM
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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

Ann R. Thryft
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Blogger
Re: Visual inspection beats all
Ann R. Thryft   6/14/2012 12:02:16 PM
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Nancy, I'm always surprised when in a group of people discussing what to do about a problem with a structure or a machine and most of them want to theorize about possible problems/solutions or wave their arms trying to describe the problem instead of going and looking at it. That sometimes includes engineers, I'm sorry to say. Good point about the tower legs design--why weren't they tested in/designed for high winds?

streetrodder
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Gold
Re: Visual inspection beats all
streetrodder   6/15/2012 4:53:13 PM
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To the comments about designing for high winds.

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...

Tool_maker
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Platinum
Re: Visual inspection beats all
Tool_maker   6/20/2012 1:03:32 PM
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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.

Rob Spiegel
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Blogger
Re: Visual inspection beats all
Rob Spiegel   6/21/2012 5:04:52 PM
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That's amazing, Tool_maker, that the trees would make such a profound difference in your ability to receive signals.

mrmikel
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Iron
Re: Visual inspection beats all
mrmikel   6/30/2012 3:26:37 PM
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Our signals come from a 200 watt translator several miles away.  When it rains, the signals deteriorate because of a large tree across the street in the line of sight of the antenna.

Rob Spiegel
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Blogger
Re: Visual inspection beats all
Rob Spiegel   7/2/2012 1:54:42 PM
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Interesting, Mrmikel. How does the rain factor in. Does the rain make the tree more dense?

mrmikel
User Rank
Iron
Re: Visual inspection beats all
mrmikel   7/2/2012 2:14:27 PM
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Darned if I know.  Its effect seems to be worse on one channel than the other, but all are in the UHF 40-50 range and all digital.  I have suspected that translator antenna might be flaky, but I'd have thought it would have been fixed if it were a problem.  It used to be at a different location but I moved it since it looked into two trees in my yard on the other side of the house.

This is a retirement town though, so maybe they just think there is something wrong with their setup, or they are working with a better antenna than mine: a corner reflector that fell off the house in the a windstorm, then had a tree limb hit it when the neighbor was taking down his tree!  I am afraid the mast still has a bit of a up tilt.

 

Rob Spiegel
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Blogger
Re: Visual inspection beats all
Rob Spiegel   7/2/2012 2:28:53 PM
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Huh. At any rate, I find it interesting that the reception problem due to the tree becomes worse when it rains.

rathomas
User Rank
Iron
Re: Visual inspection beats all
rathomas   8/28/2012 1:01:32 PM
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Rain fade and attenuation due to foliage are real, but are much more of a problem in the GHz region than around 650 MHz.  I believe he said the channels were all digital, so if he has a marginal signal on a good day, maybe just a little bit more attenuation is enough to trip the all-or-nothing barrier.

warren@fourward.com
User Rank
Platinum
Re: Visual inspection beats all
warren@fourward.com   7/9/2012 10:45:02 AM
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Reminds me of the time I went up a tuna boat mast to see why the VHF radio was only receiving signals from the boat tied up next to it.  When I looked for the antenna, it wasn't even there.  I guess a bird had hit it and it was weakened from the sun and sheared off.


Look before you leap.  I could have spent hours checking out the radio when it was nothing more than the antenna- or lack thereof...

 



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