>> I had built antennas privately for several years and
utilized a variety of element junction techniques, including fully
welded joints. I don't recommend this approach, as making changes is
quite difficult! <<
Yes but....
If one establishes that the antenna has all adjustments finalized at the
actual mounting heigh and position then is not heli-arching all the
aluminum joints the ideal? A great many commercial yagis are welded in
position. Welded antennas look great as they never rotate, loosen, or
move and they are always 100% electrically in contact. If a weld
breaks you either have a bad weld or a mechanical harmonic problem to
address. Welded joint antennas look great, last and perform in my
experience Tom.
What are your thoughts on the above Tom? I value your input.
Tom what is your feeling on pinning elements to boom, pinning booms to
masts and pinning the mast to the rotator? Telrex used to cross drill
and pin all of these in some applications that I have taken apart.
Nothing ever rotated in these pinned applications. How much pin is
correct in terms of diameter and material becomes an interesting
mechanical engineering question. In one application I found that
dissimilar metals (a hard pin) lead to elongation of the aluminum. Some
studies show that large diameter pins can lead to premature failure of
the tube pinned.
What are your learned thoughts on this pinning topic Tom?
It is great to have an avenue of communication so readily available with
a major amateur antenna manufacture. Thanks in advance.
Joe / W8SS
--
Thanks....Joe E. Mesh, D.M.D.,C.A.G.S.(Prosthodontics)
from Beautiful Downtown HELL, Michigan USA
11/18/97 09:36
_______________________________________
Always available at:
jm@drsmesh.com -or- W8SS@drsmesh.com
Please visit our Web Page at:
http://www.drsmesh.com
---------------------------------------------------------------------
PGP PUBLIC KEY AVAILABLE ON REQUEST
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search
|