1/2" or 3/8" LDF has always been my preference for jumpers, never had a
problem related to a connector damage due to lack of flexibility causing
over-stress at a connector, either at the antenna or at the main
transmission line. Maybe there are some ham-grade antennas where a
less-flexible jumper could pose a problem, but I've never had any problems
with commercial antennas in this regard. Of course, for dipole arrays,
yagis, and other commercial antennas that have built-in pigtails, this is a
non-issue to start with, but for dishes, panels, fiberglass omnis (except
for Sinclair and a few others that have pigtails), etc. that don't have
integral pigtails, I'd never hestitate to use a 1/2" jumper. Most carriers
still spec regular 1/2" jumpers AFAIK, including CommScope which is even
stiffer than LDF.
Superflex has a thin jacket that can cause problems outdoors. The helical
corrugation tends to let water spiral downward if you get a knick in the
jacket. Yeah, it can be used outdoors, just be careful how it's dressed to
ensure it can't rub against anything that might damage the jacket.
--- Jeff
> -----Original Message-----
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Joe
> Sent: Sunday, September 13, 2009 4:03 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] Re: coax cable
>
>
>
> We had thousands of 1/2" hardline jumpers connected to antennas at my
> last job. It was the standard to use 1/2" LDF4-50A for the jumper.
>
> Joe
>
> MCH wrote:
> > To reduce vibrations from the antenna being conducted to
> the feedline.
> > As it's not flexible, it will crack and/or break. I've also
> seen cases
> > where the antenna connector was vibrated right out of the antenna.
> >
> > Adding the flexible jumper acts as a 'shock absorber' and
> absorbs any
> > vibrations.
> >
> > That's why they include jumpers with commercial antennas.
> >
> > Joe M.
> >
> > Joe wrote:
> >
> >> OK, why? I've had this argument before......Joe
> >>
> >> MCH wrote:
> >>
> >>> Hardline/Heliax should *never* be connected directly to
> an antenna.
> >>> ALWAYS use a jumper.
> >>>
> >>> Joe M.
> >>>
> >>>
> >>
> >> ------------------------------------
> >>
> >>
> >>
> >> Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >> ----------------------------------------------------------
> >>
> >>
> >> Internal Virus Database is out of date.
> >> Checked by AVG - www.avg.com
> >> Version: 8.5.387 / Virus Database: 270.13.38/2274 -
> Release Date: 07/31/09 05:58:00
> >>
> >>
> >
> >
> > ------------------------------------
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>
>
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 8.5.409 / Virus Database: 270.13.78/2347 - Release
> Date: 09/13/09 05:50:00
>
>
>
