> I think I will just go with a basic Kreckman, Diamond or > Comet (in that order) and some RG-214.
I'd still go with 1/2" just for the sake of longevity. Surely someone local
could give you an end-of-reel piece that long?
> It is looking like the Site will require less than 20 feet of
> Coax from Duplexer to Antenna, and it will not be a tower,
> but inside the Elevator Access Building at the top of the
> local Hospital.
One problem you may run into is desense caused by being in the near-field of
the antenna. I've fought this problem at several rooftop sites and at a
site where the equipment was mounted at the top of a firetower-type
structure. You may find you need to take additional shielding and bonding
measures at your cabinet if you end up with desense.
> The Hospital is close to a Hercules Powder plant that makes a
> number of products and produces a hostile environment for
> anything metal in the area. The location is also line of
> site to the Inter-Coastal Waterway and the Atlantic Ocean.
> End result is antennas will be budgeted for replacement on a
> basis determined by usable lifespan of original.
Yeah, I had antennas on top of a smokestack at a fossil-fuel power plant
right about 100 yards inland from the Atlantic Ocean. Aluminum antennas
like yagis had to be changed about every 4 or 5 years, even those with black
nometallic coatings. Stationmaster radomes looked like they were "melting"
after a few years because of the acid.
A friend of mine who works for a company that does a lot of military/DOD
work contracting spray-coats their antennas with a specific version of RTV
that is designed to bond well to aluminum. He says they use the antennas on
destroyers, aircraft carriers, etc. where saltwater spray is the big enemy.
Apparently they did a lot of studies and found that this technique was the
best. Wrapping the antenna with electrical tape is an option (this used to
be a factory option for Decibel dipole arrays, not sure if they still do it
or not).
> I have around 100 feet of new 1 5/8 Andrews hardline left
> over from a Cellsite installation, but don't care to float
> the loan for connectors and then have to pay for extra guy
> wire on the opposite of the tower to bring it back into plum. :)
If you find a scrap of 1/2" I'll send you some used connectors for free, or
if you really get desparate, I'll send you a scrap of 1/2" myself if you
want to pick up the shipping tab.
--- Jeff
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