Tom, I am presently building a 4 in line vertical array for 80 meteres
and can
offer the following:
Structural program for calculating stresses is in Ham Radio Dec 98 by
K5IU
I use his spreadsheet with some modifications. The verticals that I have
designed utilize the bottom portion of a City lamp standard. Those are
the ones
along the streets with the curved portion to support the lamp. When you
cut the
curved portion off you have about 32 ft of tampered lamp standard. You
can buy
these at the steel company where your City disposes of them.
The base is about 12 X 12 inches square base with 1.25 inch one and you
can
mount these into a concrete pile.
Above the 32 ft I put the following material:
5 feet 2 in steel pipe schedule 40
5 feet 1.5 inch Al pipe schedule 40
5 feet 1.25 inch Al pipe schedule 40
5 feet 3/4 inch Al pipe schedule 40
2.5 feet 7/8 Al Tubing .065 wall
2.5 feet 3/4 in Al Tubing .065 wall
2.5 feet 5/8 in Al Tubing .065 wall
last 5 -7 feet with 1/2 Al tubing .065 wall
Both the steel and the AL is rated at 40,000 psi. You can substitute
.058 wall
for the .065 wall. The .058 wall is pricey here but it fits nicely into
the
next piece.
The verticals are self supporting and designed for 75 mph wind with + 15
mpg
gusts.
If anyone is interested I can send you the spreadsheet and pictures of
the lamp
standard directly.
Denis Ve6AQ / VE6FI
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