I have seen several Force12 antennas that have failed in my part of the
world in a tropical salt water environment due to corrosion and mechanical
wear from wind.
If I were assembling one, I'd be tempted to use swaged collar rivets:
http://www.aircraftspruce.com/menus/ha/rivets.html
These would hold better - they grip the tubing tighter because they deform
the aluminum more under the collar of the rivet.
I'd also use something to chemically protect the rivet
(Boeshield/Corrosion-X) after it was installed.
Careful drilling "perpendicular holes" - better to go down the length of the
tubing a few cm so as not to provide a weak point in the element.
73,
Mickey N4MB
On Fri, Feb 18, 2011 at 10:13 AM, Chet <chetmoore@cox.net> wrote:
> F-12 antennas are pre drilled at the factory. The instructions with mine
> say
> if there are 3 holes, use 3 rivets and insert all 3 rivets in the holes and
> don't pull any of them until you know all 3 line up. If they don't line up
> you probably have that particular element reversed.
>
> On some of the driven elements they drill a 4th hole in case you need to
> adjust the SWR and on these elements only 3 of the 4 will line up. My
> instructions didn't say anything about a 2 rivet rule.
>
> If you still have 2 out of 3 rivets,insert a new one. Not sure what kind of
> failure you had. Did the problematic rivet fall out, did it get pulled all
> the way through? Just put a new one in.
>
> 73
>
> Chet N4FX
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of n8de@thepoint.net
> Sent: Friday, February 18, 2011 9:38 AM
> To: Barry Gross
> Cc: towertalk@contesting.com
> Subject: Re: [TowerTalk] Force12 rivets
>
> I believe that the rule is:
>
> put two rivets at each location .. perpendicular to each other.
>
> Someone told me that in the past.
>
> 73
> Don
> N8DE
>
>
> Quoting Barry Gross <n1eu.barry@gmail.com>:
>
> > I'm not sure if Force12 still uses riveted construction of yagi elements.
> > In any event, I just experienced my first rivet failure on my C3S (great
> > timing, huh?) and would like to avoid repeating this experience. What is
> > the tried and true wisdom on preventing rivet failure on these antennas?
> >
> > Thanks & 73,
> > Barry N1EU
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
--
Mickey Baker
Fort Lauderdale, FL
“Tell me, and I will listen. Show me, and I will understand. Involve me, and
I will learn.” Teton Lakota, American Indian Saying.
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|