Kenwood TM-321A Service Manual page 10
220mhz fm transceiver
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Also See for TM-321A:
- Instruction manual (60 pages) ,
- Instruction manual (29 pages) ,
- Instruction manual (39 pages)
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TM-321A
CIRCUIT DESCRIPTION
@
Alert
and
electronic volume control output (when
optional remote controller
is
connected)
The
alert and electronic volume control outputs
are
provided by pins P92
(CK),
P91
(DT),
and
P21
(ST)
of
the microprocessor to the 8-bit shift register
(IC3)
in
the
TX-RX
unit. P92
(CK)
and
P91
(DT)
are also used
for
the
PLL
data.
Fig.
13 shows the data transfer format.
Fig.
14 shows the data configuration.
8bit
ok
|
|
DT
MSB
LSB
sT
Fig.
13 Data transfer format for alert and
electronic volume control
01
02
D3
04
05
Ds
D7
08
Electronic
volume
control
D6 to D8 when the
DOWN
remote
controller
(option)
is
connected.
Alert
control
Fig.
14 Data configuration
for
alert and
electronic volume control
@
Tone output
The
outputs from
pins P40
to P43
and
P50 to P53
of the microprocessor
are
applied to
a
ladder resistance
network
(IC4) which
converts these signals into
an
analog
waveform with 38 possible tone frequencies combinations
67.0
to
250.3Hz. Fig.
15 shows the internal
configuration
of IC4.
@
S-meter and
RF
meter input
The
analog voltage
of
the S-meter
is
applied to pin
PTHOO
of the microprocessor,
and the analog
voltage of
the
RF
meter to pin
PTH01, After
4-bit (16-step)
analog-
to-digital conversion, the resulting
signal
is
sent
to the
display.
@
Busy input
When squelch
is
ON
and an
input
signal
is
present,
a
low input lights the busy indicator.
CTCSS
unit (option) input
and
output
The microprocessor
sends data
from pins P30, P31,
and
P61
to the
CTCSS
unit. Fig. 16 shows the
data
transfer
format.
Fig.
17 shows the data
configuration. When
a
tone
is
detected from the
CTCSS
unit,
a
H
is
applied to pin
P32 of the microprocessor to open the squelch.
S8bit
cTD
MSB
LSB
CTS
UP
Fig.
16
CTCSS
data transfer
format
CTCSS
unit MN6520 tone frequency select data
D1}
D2;
D3;
D4}
DS
DE
Ex.885Hz
LH
H
H
Fig.
17
CTCSS
data
configuration
20K
8
9
@
Remote control
(RC-10)
(option) input
and
output
When the
RC-10
remste control unit
is
connected
a
"H"
is
applied to pin INTO of the microprocessor, switch-
ing
the
following
pins
to the functions indicated:
P03
>SI:
Serial data input pin
P02
>
SO
-:
Serial data
output
pin
P01
>
SCK
:
Serial
clock input/output
pin
P53
Tone output jo
20K
P52
7
11
20K
=7
20K
6
12
2OK
=f
20K
5
PSO
131
20K
4
P43
14
20K
3
P42
15
2OK
=f
20K
2
16
2OK
=7
20K
1
P40
Fig.
15
Internal configuration
of KRR-C001
ladder resistance
network
(Control unit
1C4)
11
TM-321A
CIRCUIT DESCRIPTION
@
Alert
and
electronic volume control output (when
optional remote controller
is
connected)
The
alert and electronic volume control outputs
are
provided by pins P92
(CK),
P91
(DT),
and
P21
(ST)
of
the microprocessor to the 8-bit shift register
(IC3)
in
the
TX-RX
unit. P92
(CK)
and
P91
(DT)
are also used
for
the
PLL
data.
Fig.
13 shows the data transfer format.
Fig.
14 shows the data configuration.
8bit
ok
|
|
DT
MSB
LSB
sT
Fig.
13 Data transfer format for alert and
electronic volume control
01
02
D3
04
05
Ds
D7
08
Electronic
volume
control
D6 to D8 when the
DOWN
remote
controller
(option)
is
connected.
Alert
control
Fig.
14 Data configuration
for
alert and
electronic volume control
@
Tone output
The
outputs from
pins P40
to P43
and
P50 to P53
of the microprocessor
are
applied to
a
ladder resistance
network
(IC4) which
converts these signals into
an
analog
waveform with 38 possible tone frequencies combinations
67.0
to
250.3Hz. Fig.
15 shows the internal
configuration
of IC4.
@
S-meter and
RF
meter input
The
analog voltage
of
the S-meter
is
applied to pin
PTHOO
of the microprocessor,
and the analog
voltage of
the
RF
meter to pin
PTH01, After
4-bit (16-step)
analog-
to-digital conversion, the resulting
signal
is
sent
to the
display.
@
Busy input
When squelch
is
ON
and an
input
signal
is
present,
a
low input lights the busy indicator.
CTCSS
unit (option) input
and
output
The microprocessor
sends data
from pins P30, P31,
and
P61
to the
CTCSS
unit. Fig. 16 shows the
data
transfer
format.
Fig.
17 shows the data
configuration. When
a
tone
is
detected from the
CTCSS
unit,
a
H
is
applied to pin
P32 of the microprocessor to open the squelch.
S8bit
cTD
MSB
LSB
CTS
UP
Fig.
16
CTCSS
data transfer
format
CTCSS
unit MN6520 tone frequency select data
D1}
D2;
D3;
D4}
DS
DE
Ex.885Hz
LH
H
H
Fig.
17
CTCSS
data
configuration
20K
8
9
@
Remote control
(RC-10)
(option) input
and
output
When the
RC-10
remste control unit
is
connected
a
"H"
is
applied to pin INTO of the microprocessor, switch-
ing
the
following
pins
to the functions indicated:
P03
>SI:
Serial data input pin
P02
>
SO
-:
Serial data
output
pin
P01
>
SCK
:
Serial
clock input/output
pin
P53
Tone output jo
20K
P52
7
11
20K
=7
20K
6
12
2OK
=f
20K
5
PSO
131
20K
4
P43
14
20K
3
P42
15
2OK
=f
20K
2
16
2OK
=7
20K
1
P40
Fig.
15
Internal configuration
of KRR-C001
ladder resistance
network
(Control unit
1C4)
11
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