yeah but the reason for .058 wall is that:
2 X .058 = .116
which is slightly less than 1/8" (.125) and if you are tapering elements
stepping down an eighth inch in diameter at a time the difference
between .116 abd .125 (.009) allows the two to slide easily into the
other and subsequent tapering....
If 058 is not strong enough for what you are doing double up with the
next size down - I will do this on the center of an element where the
element actually runs either side of the center and a shorter length of
the next diameter up is slid to the mid-point of the longer tube.
73, Go Bucs
VE6JY Don Moman wrote:
>Everyone seems entrenched in building antennas from .058 wall drawn
>aluminum. Ask about .065 wall extruded tubing next time you talk to your
>supplier. It is common up here in Canada. The extruded process produces a
>less precise tube but one that is plenty good for antenna applications, at
>roughly 1/4 the cost of drawn. Compared to the prices that N9EN relayed,
>some sizes are about 1/8 the cost. Plus you get an .007 thicker wall. With
>all the money I saved, I bought a hydraulic gin pole......
>I use 6061T6 (it's the only alloy my supplier lists) x .065 wall extruded
>tubing for all yagi elements and mix and match with pipe for larger
>elements. There is no need to have elements that telescope (i.e. 058
>all) - one can design strong and inexpensive elements with this material.
>For the tubing sizes up to 1 inch, it is simple to drill out the first 4
>inches or so, so that you can insert the next element. I make it tight
>enough that a rubber headed hammer is used to forcibly join the sections
>(w/NoAlOx) and the joint is tight and rattle free, and I'm certain has low
>RF resistance, now and many years down the road. No slitting the tubing,
>compression clamps etc etc. I usually put a SS screw or two in just to be
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