User's Manual
PMP320HDW2v1
3-29
Preliminary
JUL
2010
GPS
Coax
Cable
Chapter
3:
CMM4
Hardware
Installation
Procedure
3-1
Mounting
the
GPS
Antenna
1
Ensure
that
the
mounting
position:
•
has
an
unobstructed
view
of
the
sky
to
20º
above
the
horizon.
•
must
not
be
the
highest
object
on
the
tower
.
(The
GPS
antenna
does
not
need
to
be
particularly
high
on
a
site,
which
would
give
it
more
exposure
to
lightning.
It
just
needs
to
have
an
unobstructed
view
of
the
southern
horizon.)
•
is
not
further
than
100
feet
(30.4
meters)
of
cable
from
the
CMM.
2
Select
a
pole
that
has
an
outside
diameter
of
1.25
to
1.5
inches
(3
to
4
cm)
to
which
the
GPS
antenna
bracket
can
be
mounted.
3
A
ttach
the
GPS
unit
to
the
bracket
using
4
screws.
4
Place
the
U
-bolts
(provided)
around
the
pole.
5
Slide
the
GPS
antenna
bracket
onto
the
U
-bolts.
6
Slide
the
ring
washers
(provided)
onto
the
U
-bolts.
7
Slide
the
lock
washers
(provided)
onto
the
U
-bolts.
8
Use
the
nuts
(provided)
to
securely
fasten
the
bracket
to
the
U
-bolts.
9
Connect
the
GPS
coax
cable
to
the
female
N-connector
on
the
GPS
antenna.
See
the
section
GPS
Coax
Cable
for
additional
details
on
the
length
and
type
of
coaxial
cable
needed.
10
Use
water
type
tape
and
electrical
tape
to
seal
the
connector.
GPS
Coax
Cable
The
operator
provides
the
GPS
antenna
coaxial
cable
between
the
CMM4
and
the
GPS
antenna.
It
must
be
engineered
to
length,
and
is
not
included
with
the
CMM4.
In
most
cases,
the
cable
length
from
the
CMM4
to
the
GPS
antenna
must
be
less
than
30
m
(~100
ft).