How about welding the lower non adjusting pieces?
Has anyone ever heard a credible story about a 4 square made of
irrigation pipe that failed? You could always insert a structure inside
the irrigation pipe to stiffen it. A design in wood should be
inexpensive. Some of the spray foams might be just the ticket.
Patrick NJ5G
On 1/29/2016 9:22 AM, Stan Stockton wrote:
I know aluminum irrigation tubing has been used by many with success.
Personally, I don't like it beacuse the wall thickness is so thin.
This is just my suggestion:
Buy two 24 foot lengths of 3.5 inch schedule 40 6061-T6 from your local
metals supplier. Also buy two 24 foot lengths of 3 inch x .125 wall. Cut
those 4 pieces into 12 foot lengths so you have four of each size. Use 3/8
inch stainless steel SOCKET HEAD CAP SCREWS and the Optibeam style of
element fastening (larger hole on one side to allow head to clear one wall
of larger OD tubing) to join those together for each element with 3 bolts
for each. With a 12 inch telescope you will have 23 feet ending with 3
inch x .125 wall. Then for each element buy 6 foot lengths of every size
DXE has of .120 wall tubing starting at 2.75 inch OD. You will need four
of each size except the 1.5 inch OD where you would just have 3 feet of
that size for each vertical - so you need two six foot lengths of the 1.5
OD. Use the same fastening method and telescope everything through the
1.50 inch OD by six inches with two bolts for each joint. Then for the
rest, starting with 1.25 inch telescope them by four inches and use bolt
sizes shown below. The 1.25 through 1 inch is just regular .058 wall also
available from DXE. The total length of this vertical will be about 70
feet.
So the taper schedule for what I described is:
OD WALL EXPOSED Length Socket Head Cap Screw Size
3.5 .216 144
3.00 .125 132 3/8 x 4 inch
2.75 .120 66 3.8 x 3.5 inch
2.50 .120 66 3/8 x 3.5 inch
2.25 .120 66 3/8 x 3 inch
2.00 .120 66 3/8 x 3 inch
1.75 .120 66 3/8 x 2.5 inch
1.50 .120 32 1/4 x 2.5 inch
1.25 .058 68 #10 x 2 inch
1.125 .058 68 #8 x 1.75 inch
1.00 .058 68 #8 x 1.50 inch
Although it would free stand with probably a 40 MPH wind, I would guy it
one time, maybe from the top of the 2 inch section.
I am just guessing the total cost will be well less than $1,500 for four
verticals. You will have to use a drill press and a V block to drill a
bunch of holes and engineer the method to walk it up and have it insulated
from ground.
73...Stan, K5GO
On Wed, Jan 27, 2016 at 9:05 AM, Daniel Hileman <n9wx@hotmail.com> wrote:
Hi All,
I am looking for advice on material to use for an 80m 4 square. Looking
for the cheapest way to build an 80m vertical. I have looked at
towers,used utility poles etc. (Utility poles look like the best option so
far.) Curious what you guys use. I know that it may not be cheap, but I
would like to do the verticals as cheaply as possible and looking for your
input. I do not have 70' trees to hang a wire from (hihi) as I know this
would be SUPER cheap. ;-) Like I said, I do not expect it to be free, but
$1,800 for an 80m vertical from "Zero-five" antennas is crazy, and really
dont want to spend $3,000++ on a 4 square! Looking at options! lol. I know
it's alot of aluminum,etc.
73,
Dan N9WX
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