EasyManuals Logo

Icom IC-2GA Service Manual

Icom IC-2GA
62 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #12 background imageLoading...
Page #12 background image
(4)
VCO
CIRCUIT
(RF
UNIT)
D701
changes
the
inductive
reactance
of
the
oscillator
(Q702),
shifting
the
receive
and
transmit
frequencies.
Varactor
diode
D702
provides
frequency
control.
Q703
buffer
amplifies
the
VCO
output
signal;
Q701
buffer
ampli-
fies
the
PLL
feedback
signal.
(5)
UNLOCK
SENSOR
CIRCUIT
When
the
PLL
circuit
is
unlocked,
pin
7
of
IC2
is
"LOW"
and
a
"LOW"
signal
is
applied
to
the
unlock
sensor
(Q23).
The
unlock
sensor
outputs
a
current
amplified
"LOW"
signal
to
the
CPU,
ІС503
(ріп
60).
r
ки!
|
M
VCO
UNIT
|
| |
|
|
|
0703
|
from
|
Buffer
|
МЕЗЕ
=.
|
>
+
>
T/R
switching
|
|
circuit
RF
bandpass
filter
-
4
disp
|
ола
|
Buffer
|
шег
|
|
CHARGE
PUMP
|
>
|
\
CONTROL
|
|
Q21,
Q22
LC
сылын
ы”
шш
лш
4
F
RANGE
14|
8
ІС?
|
|
ТЕЛЕ
COUNTER
AND
LATCH
ZN
CHARGE
PUMP
Q6,
Q8
12
L
|
|
PHASE
DETECTOR
5
DATA
CK
|
SHIFT
REGISTER
4-4
POWER
SUPPLY
CIRCUITS
(1)
VOLTAGE
LINES
Battery
pack
output
that
passes
through
the
power
switch.
Vcc
is
applied
to
the
power
module
(!С3),
the
AF
power
amp
regulator,
and
the
following
5
V
lines.
Common
5
V
current-amplified
at
(Q207,
Q208)
using
IC
output
as
a
reference
voltage.
The
heat
factor
of
the
voltage
at
0207
(Vac)
equals
that
of
the
junction
voltage
at
Q208.
The
output
is
stable
even
with
regard
to
tempera-
ture
changes.
Common
5
V
controlled
by
the
power
save
function.
Current-amplified
at
Q213,
Q214.
5
V
controlled
by
the
power
save
function.
Current-amplified
at
Q211,
Q212.
Used
by
the
receiver
circuits.
5
V
current-amplified
at
Q209,
Q210.
Used
by
the
transmitter
circuits.
PLL
STLB
COUNTER
AND
LATCH
(2)
VOLTAGE
REGULATOR
CIRCUIT
(MAIN
UNIT)
When
the
battery
voltage
is
5.5—16
V,
the
regulator
(ІС204)
outputs
a
reference
voltage
of
5
V.
The
noise
components
are
removed
by
the
noise
filter
(C220,
R213).
This
output
is
applied
to
the
current
amplifier
(Q207,
Q208).
(3)
CPU
POWER
SUPPLY
CIRCUIT
(LOGIC
UNIT)
When
the
power
is
turned
off,
voltage
from
the
lithium
battery
is
applied
to
the
CPU,
ІС501
(pin
52)
via
D502.

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the Icom IC-2GA and is the answer not in the manual?

Icom IC-2GA Specifications

General IconGeneral
BrandIcom
ModelIC-2GA
CategoryTransceiver
LanguageEnglish

Related product manuals