Let me tell you, my Static's professor (Is that old fossil still
alive??) would be proud that I even remember as much of what he taught
me as I've already told you. We're really digging into the dark ages now.
IF you could assume that the base of your guyed tower was not fixed in
position, but instead was allowed to slide frictionlessly in the
horizontal plane, and assuming that the wind was 50 MPH at all points
along the total height of the tower, then the increase in guy tension
due to the wind would be basically equal in all three guys because the
tower would deflect horizontally an equal distance along it's height.
BUT, since the base of your tower IS fixed to one degree or another
(set in concrete, single pin, etc), the horizontal deflection of the
tower will be more at the top than it is at the bottom, so the increase
in guy tension will be somewhat more in the upper set of guys than it
is in the lower set. Being a tweek and not a structural engineer, my
guess is that this difference in guy tension will still not be a very
significant bearing on the overall problem.
Actually, I'd gladly give you some real numbers on this, but I ran out
of sufficient significant digits on my 5 inch Castell slide rule to
complete the calculation. I really keep the slide rule and a 4X500 on
my desk so young puke engineers can say "Wow! What are those?" Then I
can proceed to impress them with my vast and limitless knowledge of the
inane and arcane.
73,
Brad, W5CGH
In a message dated 9/7/01 11:25:54 AM Pacific Daylight Time, wbarby@telus.net
writes:<<
Hey Brad, if your 5 inch rule doesn't give you sufficient significant
digits, I can loan you my 'circular' (about 10 inch diameter)
slide rule that is equivalent to about 8 or 9 feet! heh heh!
Wilf VE7QO
>>
Brad: All hams should have to take the course of Static's for tower
applications. I still have and use my K&E Log Log Duplex Vector Slide Rule.
It's great for computing dB's and Ballistic problems also. It's handy for
ratios etc. Have you ever tried to add or subtract on a slide rule (trick
question)? Wilf is right about the greater resolution of the circular slide
rule. I even have a small slide rule as a tie clasp. The batteries never
wear out like those in my 8 different engineering calculator--no polarity
problems either! Here's a tip on battery life with those mercury jobs. When
you think they are dead after a year or so, clean them with a pencil eraser
and the contacts each time you think they are dead. I had a set in both my
HP11C's last 8 years. There must be some Mercury outgassing doing some
corroding to the contacts and "your nerves." Mercury poisoning mainly from
Mercury fillings is the biggest cover up on earth at this time by the ADA.
Other countries have banned mercury fillings and steps have started
here--fortunately.
There is the joke about the student class asked to multiple 2x2 on the slide
rule. Lets see "2x2 equals 3.99999999999--call it 4."
One year I got the school to give 2 weeks of a free math class before the
regular classes and not one student dropped out that year due to all the
usual excuses of work, money or other reasons. I got a raise also.
The first year we used calculators in a class I taught we finished the normal
work load 3 weeks earlier and did more review--they all got A's. It's the
"simple math" students have more of a problem with than the technicalities of
electronics, chemistry or physics. The calculator took care of most of the
math problems.
In a Metrics class I taught I pointed out that when you go to a gas station
to get air for your tires, the terms are different in Metrics. Instead of
saying "give me 30 lbs/sqin pressure give me 200,000 Newtons/Meter Squared."
A student said "what's that in FigaNewtons? k7gco
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