On the other hand, in Massachusetts I've had the squirrels chew both the
jacket of some LMR400 as well as the aluminum boom on a yagi. It seems that
usually the damage is done in the spring, or. At least that is when I
notice it. It's possible it was done over the winter when food was scarce.
Sean WA1TE
On Wed, Oct 31, 2018, 23:40 Jeff DePolo <jd0@broadsci.com> wrote:
> > There is:
> >
> > 1) Smoothwall hardline.
> >
> > 2) Spiral corrugated hardline (like FSJ4).
> >
> > 3) *ringed* (my term) corrugated hardline (like LDF4).
>
> "Helical" corrugation is the term for the "spiral" type, which is how the
> original Heliax was made, and is how it got the name.
>
> "Annular" corrugation is the technical term for the "ringed" type.
>
> Modern Superflex Heliax type cables (e.g. Commscope FSJ, RFS SCF), and most
> air-dielectric corrugated cables (HJ, HCA, et al), use helical corrugation.
>
> Modern non-Superflex, foam-dielectric, corrugated cables like LDF, LCF, et
> al have annular corrugation.
>
> As Steve said, Superflex is not a good choice outdoors. We never, ever,
> use
> Superflex outdoors in commercial work. Jumpers from the main feedline to
> the antenna are made of regular Heliax (typically 1/2"), not Superflex.
> Superflex gets used indoors where its flexibility is needed and where
> durability and the elements are not a concern.
>
> I can't count how many water-logged Superflex antenna jumpers we've had to
> change out over the years, installed by those that didn't know any better.
> Lessons learned the hard, expensive way.
>
> Burying regular (non-Superflex) Heliax is fine, and no additional
> protection
> is generally required except in unusual soil conditions (rocky, unstable),
> or when it could be subject to crushing forces such as if buried at a
> shallow depth below a vehicular pathway. There are many thousands of miles
> of directly-buried Heliax in the ground at AM broadcast facilities around
> the world.
>
> --- Jeff WN3A
>
>
> ---
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