Cubic SWAN SS-15 User Manual

IF
AMP
-
The
first
IF amplifier
is
a dual
gate
M0SFET
transistor
anplifier
Q407.
The
amplifier
is
controlled
by
ALC during
transmit
to insure
that
other amplifier circuits are not
overdriven.
The
"S'r
meter is stil1 connected
to
the first IF amplifier as it
is
during
receive, but
the
neter reading during
transnit is
an
indica-
tion
of
ALC
action. When the
meter
moves
off
of zero, the ALC
circuit is reacting
and
it is
an
indication that the nornal
forward
power
output
or
25%
(of
norrnal)
reflected
power
has
occurred.
XMIT MIX
-
The transmitter
mixer
is an
integrated
circuit.
The
output of the.rnixer
produces
the
desired
RF output
frequency by
mixing the
output
frorn
the
first IF
amplifier and the
VFO
output.
The
voltage to the mixer
is
keyed through a transistor
and RC
shaping network
when operating
CW.
BROADBAND DRIVER
-
A single
transistor
Q202
is
nary linear
anplifier.
Although
it
contains LC
is
a
broadband
ampLifier
(on
the seLected
band)
adjustment
or tuning
by the
operator.
used as a
prelimi-
tuned
circuits
it
requiring
no
PRE
DRIVER
-
Ancither broadband
arnplifier
provides
additional
;,
anplification
of the transmit signal.
A
FET
transistor
Q205
is
followed
by transistor
Q204.
Both of these transistor
anplifiers
operate
Class A linear.
DRIVER
-
The
driver arnplifier is the RF
output anplifier
for the
SS-15 and
is
the
driver
anplifier
for the
SS-100
and SS-200.
Three
bipolar
transistors
are used
as
Linear
anplifiers to
produce
ap-
proximately
5 watts RF
output.
LOW
PASS
FILTER
ASSEMBLY
very linear, they still
frequency.
The low
pass
50
db
or
more
below
the
filter
is
used
for
each
In cases where
TVI
is a
recommended.
-
Although
the transistor
amplifiers
are
produee harnonic nultiples
of the
fundamental
filter is
required to keep
these
harmonics
desired fundamental.
A
different
low
pass
band
and
is
selected
by the
BAND
switch.
problem, a
good
1ow
pass TVI filter
is
ALC
DIRECTIONAL DETECTOR
-
The directional
detector serves
several
functions.
First it
provides
the
control voltage
to
protect the
transistor
linear arnplifiers.
Either
ful1 rated
power
outPut
in
a
forward
direction
or 254 of
full rated
power in
a
rqflected
direction
EaGefthe
directional
detector
to
actiirate
the
AlC-ffilEluces
the
drive
power. In
this way the
transceiver
is'fu11y
protected
for
antenna shorts,
opens or severe
nisnatch.
Second,
the
directional
detector provides-
the control
voltage
to the
ALC
so
that
the
ALC
can
be
adjustbd
(at
the factory)
to
limit
maxirnun
RF
output.
This is
done to
preserve
linear opbration
in the RF
amplifiers.
Increased
drive
frbm
the
nicrophone-
gain
or
CW drive will
result in
increased
ALC
action
but not an increase
in RF
power
output.
a1

Cubic SWAN SS-15 Specifications

General

Brand	Cubic
Model	SWAN SS-15
Category	Transceiver
Language	English