Cubic SWAN SS-15 User Manual

CIRCUIT
THEORY
OF
OPERATION
GENERAL
The
SS-15,
SS-100 and
SS-200
transceivers use
all
solid-state
circuits.
Many of
the
latest
transistors
and
ICrs are used
and
several new
circuits, designed
just
for these
transceivers,
have
been included.
The development of the single sideband
signal
with
suppressed'carrier
is
achieved through
the use of
a balanced
rnodulator and a crystal
lattice bandpass
filter.
The
following
paragraphs
of this
section
provide
a
detailed
description
of
all
systens-and
circuits.
It is suggested
that
the schematic
drawing
at the end of this
nanual be
opened for easy
viewing
during the
reading of this
section.
TMNSCEIVER SYSTEM
All
cir,cuit
functions are
integrated
into
a
systen
whigh
performs
the transnit
and
receive functions.
Figures
4
and 5 show
block
diagrans
of the transmit
and
receive
systen,
It should
be
noted
that the
asterisks on various
blocks
indicate
that
the
circuit's
in that
block
are
used
for both
transmit
and
receive.
As
an d,x-
anple, the
VFO
is a single
circuit
used
for
both
transmit
and:'
receive.
RECEIVER CIRCUITS
The receive systen
is
shown
in
Figure
4. The system
is
a
single
conversion superheterodyne
receiver
utilizing
a
prod. ct_
det6ctor for
SSB detbction,
an IF
arnplifier
with
a
crystal
filter
at the input,
a
noise
blanker
circuit with
a FET
switch,and
other
standard
iuperheterodyne
circuits. Receiver
circuits
common
to
the transrnit.ter
are the VFO,
AGC/ALC,
crystal
f ilter,
IF amplif
ier
carrier oscillator
and the
8 volt
regul,ator.
The following
des-
cribes
each
circuit in
the receiver.
RF AMP
-
The RF
amplifier
uses
a dual
gate
M0SFET
transis_tor
Q205.
The LC circuits
arb tuned
at
both
the
input
and output
of
the
anplifier using the
PRESELECTOR
control.
The individual
coils
foi each
band are
selected
by
the BAND switch.
The
amplifier
is
AGC controlled
to reduce overloading
and
cross
modulation.
,
-
20-

Cubic SWAN SS-15 Specifications

General

Brand	Cubic
Model	SWAN SS-15
Category	Transceiver
Language	English