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Figure 6 shows the preset selector circuitry.
COUNTER
CIRCUIT
IC902
CONNECTER
CP2-CS2
$1-9
:
O
LW MW SW1SW2SW3
a
or
oy
DISPLAY
Preset
terminal
A. For FM:
(a) Terminal 6 of IC902 becomes an ''L" level. (through connectors Pin 1—-L120—Pin 7-+GRND)
(b) Terminal 5 of IC902 becomes an ''L" level. (through S1—9 .—Connector Pin 2.)
(c) Terminal 4 of C902 becomes an "'L"' level. (through S1—-9—» D106—+Connector Pin 3)
(d) Terminal 3 of IC902 is set at an ''L"' level. (through S1—9->Connector Pin 4)
As a result, (refer to the table in figure 5) the counter circuit subtracts 10.7 MHz from the local oscillator
frequency (the input signal), and the result is displayed as the reception frequency.
B. Inthe same way, for the LW, MW and SW bands the condition of each preset terminal is changed by the band
selector (S1—9) consenquently, the preset frequency shown in the table in figure 5 is obtained, and the correct
reception frequency is displayed.
IV. Counter Signal Circuitry
Figure 7 shows the counter signal circuitry.
DRIVER
CIRCUIT
C901
COUNTER
CIRCUIT
IC902
Counted
Frequency
from
Local
OSC
(9) X'tat OUT
FM: 98.2--118.7 MHz
LW: 605~865 kHz
MW: 987~2.072 kHz
Preset
DISPLAY
terminal
SW1: 5.2-- 10.0 MHz
SW2: 10~18 MHz
SW3: 18~ 32 MHz
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