SEA 1612C - Electrical Configuration; Mechanical Configuration

E.G.: when
two
antennas
are
in
close
proximity,
it is
possible
that transmitting
on
one
antenna
may
cause
considerable
RF
to
be
coupled
into
the
adjacent
antenna.
This
can
cause
the
tuner
to
reset,
disturbing
the
operation
of the
radiotelephone.
In
such
cases,
the
"TUNE
LocKour''
feature
of
the sEA
1612c
can
be
used
to
prevent
the
SEA
1612C
from
entering
the
tune
mode
until
the radiotelephone
it is
associated
with is
actually
transmitting.
1
,2
ELECTRICAL
CONFIGURATION
The
sEA
1612c
matches
the
complex impedance
of the
antenna system
to
a nominal
50 ohms
by-'selecting."the:..,proper
network
from
a
possible
combination
of 64
values
of input
c,
32
values
of
output
c
and
s1z
values
of
series
L.
Network
configuration
is
automatically
determined during
the tune
cycle and
may
be
either
a Pl
network
or either
of
two
types
of
L
network.
whenever possible,
the
L
network
will
be
selected f
or
maximum
eff
iciency.
Tuneup
is
entirery
automatic
and
may
be
accomplished
on
voice
signals,
making
it
unnecessary
to
provide
a
"low
power
tune"
mode
in
the
trans
m itter.
1.3
The
various
RF
sensors
in the SEA
function
down
to
power
levels
of
feature makes
the SEA
1612C
equipment
such as
the SEA 225
circuitry
to
reduce
the output
power
hish
VSWR.
MECHANICAL
CON
FIGU
RATION
1612C are designed
to
10
to 20 watts. This
compatible
with radio
which is equipped with
level in
the
presence
of
All
of the circultry
of the SEA 1612C ls contained
on
printed
circuit
board PCB-1616-01.
This
printed
circuit board
is
mounted
on
an
aluminum shield
plate
with
six 6-32 stainless
steel screws. The
shield
plate
is held in
the
molded
weather
housing wlth four 10-24
stainless steel screws.
(Figure
1.3
shows the
outline
and
mounting
dimensions of the
molded
weather housing.)
The
printed
circuit board
is
solder-masked
which
helps to
prevent
corrosion and
moisture
problems.
1-2