On 2/24/2011 8:30 AM, Gary E. Jones wrote:
> I have a bunch of Force 12 antennas up in the air, all without any problems
> for years. However, that is probably because a good friend of mine bought a
> bunch before me, and rather quickly had one of the sections of element tips
> simply drop to the ground. The preferred method of construction was to have
> three rivets, all on positioned on the bottom of the element and on only one
> side of the element. There was enough "play" in the telescoping elements
> that the rivets would simply gradually be worked by the play until the
> rivets dropped to the ground and the element sections worked out of their
> telescoping tubing and drop to the ground also.
>
> MY friend (K5JZ) spent a lot of time talking with Force-12 and they came up
> with the process of using 6 rivets per junction, three on one side of the
> tubing and opposed by three on the other side of the tubing so they were 180
> degrees apart. Placing them on opposing sides removed all the very small
> "wiggle" of the elements and held them firmly in position.
I "would think" that two or 3 sets at 120 degrees staggered with a 60
degree offset would give the most secure connection.
BTW I mentioned way earlier in this thread that my force 12's didn't
have blind rivets, but I discovered the two packages of *spare* rivets
from force 12 ARE blind rivets. Not sure why those in it aren't.
OTOH I really don't see as if it'd make much difference. If properly
seated either type should seal and if not neither type would seal properly.
I don't like the idea of rivets on line 180 degrees apart. It makes a
good secure connection, but at the expense of the element strength along
one axis which is admittedly in a low stress area so it probably makes
no difference. OTOH it would be a good idea to avoid the practice in
higher stress (or loaded) areas.
73
Roger (K8RI)
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