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RC-646D/L
CIRCUIT DESCRIPTION
AND-GATE For CPU Key Matrix
Operation Description
A
To}
2
PIN 7 -—- GND (0V)
B
PIN 14 ---- Vpp (5V)
Vop (5V)
:
Te
GND (OV)
an | a
Synthesizer Unit 4-Com: «PD 1708G
FUNCTION
OUTLINE
Receiving frequency, Channel spacing, Reference frequency, Intermediate frequency
FM band
Frequency range
Channel spacing
|
Soke
|
Soke
kHz
* MANUAL 25 kHz
87.50~108.0 MHz
AM band
Frequency range
Channel spacing
CPU Key Matrix Operation
The source clock from the CPU is input to A-input via the
AND-GATE
at any time to apply the control signal to B-
input.
When the signal is input to B-input, the output Q goes
high and input as the CPU key input. When the B-input is
low level, output OQ is always low. Output OQ is synchro-
nized with input A.
Reference frequency
Intermediate frequency
12.5 kHz
10,700
Reference frequency
Intermediate frequency
522-1611
kHz
9kHz
9kHz
450 kHz
193 ~281 kHz
"
OkHz
1 kHz
450 kHz
"MANUAL 1 kHz
Tuning Function
(1) Auto Tuning (Sawtooth wave mode)
Seek Up: Once a Station is tuned, it is held tuned.
{2)
Manual Tuning (Sawtooth wave mode)
Manual Up/Down:
Frequency
ts advanced
up or
down
in steps by pressing the
push switch.
Pressing
for a half second or
more
advances
tt up or down
continuously
until the switch is
released
(3)
Preset
Memory Recall
6 stations on each
FM, MW,
and LW
band can be
preset independently with the 6 buttons. The last sta-
tion is stored in memory for each band when power is
turned off
10
Tape Function
(1) Tape running indicator
{2) METAL contro!
Radio Function
(1)
MONO control
Other Functions
(4)
LOUDNESS control
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