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The
output from
the
filter
is
converted
to
a
9MHz
signal
again
by
the
IC11
mixer through
the
Q42
buffer
amplifier.
FM
signals
from
the
FI6
filter
are fed
to
a special
FM
circuit.
The
9MHz
signal
is
supplied to
an
amplifier
circuit
consisting
of
Q43
and Q44,
then
is
supplied to the
AGC
or the
DETECTOR
circuit.
Finally,
the
signal
is
fed to the
AF
amplifier
circuit.
FM
signals
from
FI6
are
supplied to amplifier
and
limiter circuits
consisting
of IC12,
Q45
and
IC13.
The
limiter circuit
eliminates
noise or
AM
components,
then
the
signal
is
supplied to
a
frequency
discriminator
and
is
detected.
The
detected
signal
passes
through
a
C-R network
for
de-emphasis
and
is
supplied to the
AF
amplifier
circuit.
The
AF
amplifier
circuit consists
of
a
pre-amplifier
and
an
AF
power
amplifier
which
amplifies the
signal
to
a
sufficient
level
to
drive
a
speaker.
A
switching
circuit
consisting of
Q74
and
Q75
is
installed at
both
the Input
and output
of the pre-amplifier
circuit
in
order to cut
off
the
AF
signal
by
means
of
a
squelch
signal.
The
output
from
the
pre-amplifier
is
also
supplied to the
ACC
socket
on
the
rear panel.
The
AF
signal
from
the detecter
circuit
is
amplified
by IC19
(b).
Then
It
is
fed to the
IC19
(a)
pre-amplifier
through
the
TONE
CONTROL
circuit
consisting of
R394,
C258
and
the
TONE
CON-
TROL
on
the front
panel.
The
signal
is
supplied to the
IC18
AF
power
amplifier
through
the
AF GAIN
CONTROL
on
the front
panel.
The
AF
power
amplifier has
a
2.6W
output
capability
under
an
8
ohm
load
with
10%
distortion.
11-2
TRANSMIT
CIRCUITS
(1)
AF
CIRCUITS
•
MAIN
UNIT
•
RF
COMPRESSOR
•
RF UNIT
The
AF
signal
from
the
mic connector
is
fed
through
the
MIC GAIN
CONTROL
on
the front panel
to
Q34
and
Q35
where
the
signal
is
amplified.
The
tone
control
circuit
is
installed
between
034
and
Q35, and
varies
the
frequency
response of the
mic
amplifier.
The
signal
Is
also
supplied to the
ACC
socket through
R148
and C83.
IC9
is
a
double-balanced mixer
which
generates the
SSB
and
AM
signals.
IC9
puts
out
DSB
signals
formed by
the
AF
signal
mixing
with the
BFO
signal.
In
the
AM
mode,
an
offset
voltage
is
fed to the
modulating
input terminal of
IC9 through
R159
and
D75
so the
carrier
level
may
be
controlled
by simply
adjusting
the
offset voltage.
The
DSB
or
AM
signal
from
IC9
is
fed to the
9MHz
filter
and
the
filter
eliminates
one
sideband
resulting
in
an
SSB
signal.
The
signals
are
fed
through
Q84
to the
ICIO
mixer.
IC10
puts
out
a
455kHz
signal
which
is
fed to the
Q38
matching
amplifier
through
the
Speech Compressor
circuit
when
the
circuit
is
turned
ON. Then
the
signal
is
converted
to
9MHz
again,
and
is
fed to the transmitter
IF
amplifier
by Q1.
The
9.0115MHz
IF
signal
from
the
MAIN
unit passes
through
the
LPF
and
is
converted
to
70.451
5MHz
by
the ICS double-balanced
mixer.
The
HPF
eliminates the
9.0115MHz
signal
component
from
the
mixer output
signal,
and
the
L30
and
C67
resonator eliminate
the
61.44MHz
2nd
LO
signal
component. The
signal
is
amplified
by
the
Q1
1
dual-gate
FET
which
receives
an
ALC
voltage
at
its
1st gate.
-
50
-
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