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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