Hello Gedas,As a point of reference I have a DX Engineering 80/40 meter
vertical. It is ~57 ft high with a big trap at 32' for 40m.It's 3" aluminum
tapering to 1". I live on a big ridge and have some pretty high winds at
times. When I first put it up I thought I would need to guy it. It turns out
that it is not needed. I've watched during high winds and it doesn't move very
much. I attribute this to having a pretty low cross section/wind load.I would
definitely go with the larger diameter for strength especially since you're
going to walk it up.Please let us know how it turns out.73,Gary K9GS
-------- Original message --------From: Gedas <w8bya@mchsi.com> Date: 1/1/20
11:54 AM (GMT-06:00) To: TowerTalk@contesting.com Subject: Re: [TowerTalk]
Which Vertical is More Robust ? Hi Rick es HNY !TU for that advice. I need to
look up the weight of the heavier duty fence pipe. As these are going to be
elevated verticals which I "pivot" into place by myself I need to look at what
the total weight will be. I have about 8' of 6x6 set in the ground then use a
wooden frame that cradles around the 6x6 and pivots the verticals into place.
Kinda hard to explain but it will put the feedpoint at around 10' off the
ground, then of course the length of the vertical. So I should be able to walk
it up into place. Will check it out TU.But let me ask my question again, is it
better to go with a larger dia pipe (even if it has a greater wind load) or
better to go with a smaller dia tubing with less wind load? Assuming the wall
thickness is the same for all the members.Gedas, W8BYAGallery at
http://w8bya.comLight travels faster than sound....This is why some people
appear bright until you hear them speak.On 1/1/2020 12:23 PM, Richard (Rick)
Karlquist wrote:> Recommend that you consider chain link fence "top rail"
instead> of EMT. Get the "1 7/8 inch" OD variety. It is the same> diameter as
"1 1/2 inch" water pipe. It is actually intended> to be structural. There is
also a "1 3/8 inch" OD variety than> you can telescope. It is the same
diameter as "1 inch"> water pipe.>> Rick N6RK>> On 1/1/2020 8:13 AM, Gedas
wrote:>> HNY to all !>>>> I cannot think of a better time to start a new 40m
phased vertical >> project then the dead of winter with snow on the ground (as
usual I >> could not get to it during the summer or fall).>>>> Anyway, I have
drawn up two possibilities for a pair of 33' self >> supporting verticals. Both
start out with a 10' length of EMT but one >> choice starts out with a larger
dia then the other before I switch >> over to tapering aluminum sections.>>>>
A) Starts out with a 10' length of 1-1/4" EMT followed by tapering 5' >>
sections of aluminum tubing (4' long exposed, 1' inside the previous >> lower
section) until the very top length section which will be 3/4" >> OD dia. These
will be standard DX engineering aluminum tubes.>>>> B) Starts out with a 10'
length of 1-1/2" EMT, then a 5' length of >> 1-1/4" dia of EMT (4' long
exposed, 1' inside the previous section of >> EMT) then followed by tapering 5'
sections of aluminum tubing as >> above. The only difference being this choice
would end up using 1" >> aluminum tubing as the very top piece.>>>> So the
obvious difference between the two are that choice A) uses >> just one length
of thinner EMT and overall thinner aluminum tubing >> sections to the top while
choice B) uses 2 lengths of larger dia EMT >> and then larger dia aluminum
tubing to the very top.>>>> I do not have the software to analyze choice A) vs.
choice B) in a >> high wind situation. I am uncertain if the stronger, larger
dia >> tubing with it's higher wind load will be a plus or a minus in the >>
end to it's overall strength. Any thoughts or comments on which one >> will
survive better during heavy wind conditions? TU>>>> Gedas, W8BYA>>>> Gallery at
http://w8bya.com>> Light travels faster than sound....>> This is why some
people appear bright until you hear them speak.>>>>
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