Good taper schedule for aluminum tubing is to use diameters differences
of 1/8 (0.125) and to use a wall of 0.058 thickness. These telescope
together very nicely. Note the difference betweeen the 0.125 diameter
differences and two times the wall thickness (2 x 0.058=0.116) allows
for a 0.009 clearence of the innner to outer tuging. I use then the saw
cut and stainless steel hose clamp technique to secure. Always remove
ALL burrs when making any cuts. All dimensions are english.
Previous posts gave wall thickness of aluminum as .0120 which is very
thin and not a standard in the antenna world.
My 18th Edition of the ARRL Antenna Handbook has a very useful table of
aluminum tubing from 3/16 to 3 in diameters. Try Chapter 20 page 20-7.
Chapter is titled Antenna Materials and Accessories.
73 de Arne N7KA
NM
Dan Levin wrote:
>
> Does anyone have data on taper schedules for building free-standing vertical
> antennas from aluminum or copper? Is it in the Antenna Book, and I just
> missed it? What I want is a table that says something like e.g. "if you
> want to build a free-standing quarter wave vertical for 40 meters, then use
> this taper schedule - 10' 2" o.d. .0120 wall 6061 aluminum, 10' 1 5/8" o.d.
> .0120 wall, 10' 1 3/8" o.d. .0120 wall, 4' 1 1/8" o.d. .0120 wall, and it
> will stand up in an 80 mph wind without falling over if the base is good."
>
> Thanks!
>
> ***dan, K6IF
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
--
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|