Never mind, Stan. I didn't see that email to VE7RF where you answered my
questions.
It's a somewhat counter-intuitive technique. The outer tube becomes the
clamp when you deform the inner tube with the screw.
Do you orient the counter-bored screw head/screw-axis in any particular
direction relative to gravity (e.g. straight up and down with head on
top, straight up and down with head on bottom, horizontal, doesn't matter)?
73, Mike W4EF.................
On 8/13/2015 8:21 AM, Michael Tope wrote:
Stan,
A couple of questions:
1) Does the counterbore go all the way through the one wall of the
outer diameter piece?
2) Is the clearance between the counterbore diameter and the cap screw
head diameter critical?
Thanks,
Mike W4EF................
On 8/13/2015 6:53 AM, Stan Stockton wrote:
After about 40 years of making my own antennas I learned something a
few years ago when faced with assembling 65 tribanders (520 elements)
we made for WRTC2014.
I was introduced to the element joint attachment method I am told is
used by Optibeam. I was skeptical when I heard the verbal
description, having settled on pop rivets after every other
conceivable method about 20 years ago.
I made one element with pop rivets and another with a single
stainless steel socket head cap screw with a counterbore (head
clearance on socket head screw) for one wall of the larger diameter
tubing for each joint, then grabbed each one in the center and
violently shook them back and forth. The one with SHCS joints felt
like one solid piece of tubing as compared to the pop riveted one.
It is so easy and so solid, I will never mess with pop rivets again.
A V block fixture with stops, drill press and some of these bits
along with straight bits for the smaller diameter tube drilling are
all that is needed.
http://www.wttool.com/index/page/category/category_id/14686/
make the job easy in comparison to many methods. The counterbore is
important. Use stainless nylock nuts.
YMMV but I'm sold on it.
73...Stan, K5GO
Sent from Stan's IPhone
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