STE sas Milano - ITALY
Pag. 3 of 14
Fig. 2 - Block Diagram
+5 V
1
+5V
2
AV1
3
RSI ( "S")
4
ARX (AUDIO RX)
5
CD (CARR. DET.)
6
RXD (RX DATA)
7
PTT (TX ENABLE)
8
ATX (AUDIO TX)
9
TXD (TX DATA)
10
CTS ( CL. TO SEND)
11
PRO
12
PRI
13
CHD
14
CHC
15
CHB
16
CHA
17
DATA/VOICE
18
GND
19
GND
20
Q8-Q9
DATA SQ.
P/P DEV.
IC4B
S/H
IC4A
L.P.F
DISCR.
IC2A
LEVEL
RX DATA
+ 5V
FREQ/TEMP
NTC
FREQ.
FREQ.
X1
REF.
REV. POL.
F1
Q6-Q7
DETECT
PROTEC.
CARRIER
IC2B
DATA
SLICER
D4
D5
COMP.
RV1
AUDIO
AMPL.
600
AUDIO
S2
"S"
2° MIXER - IF
455 KHz
XF3
IC3B
FM
B
PM
A
S1
B
+ 5R
A
+ 5V
IC3A
TP
XF4
CER.DISCR.
Q4
IF AMP.
Q5
IF
21.4 MHz
XF2
2° LOCAL
CER.FILT.
OSC.
2° L.O. ADJ.
Q2
AMP.
Q1
LNA
XF1
FILTER
T/R
D1-D2
IC9
+ 3V
+ 5V
+ 5R
Q15
Q14
+ 5T
Q17
TXD
Q16
PTT
600
S3
IC7B
AUDIO
LEVEL ADJ.
COMPENS.
+ 5V
PM
S4
FM
TXD
IC6A
IC7A
+ 5V
uC PIC16F870
RV2
H/L
(LOW)
RV3
SWITCH
RF
SWITCH
OPTION
D6A
D6B
Q11
P.A.
Q10
HIGH/LOW
+ 5V
POWER
n.015920 (BK77)
0.5 W BOOSTER
PLL
B
S7
POWER
A
n.015921 (BK78)
A
S6
B
+ 3V
VCO
+5T
RF
Q12
BUFFER
SUB. n.015918 (BK77)
VCO-PLL UNIT
LPF
SUB. n.015919 (BK78)
TP1
ADJ.
MOD1
DEV. ADJ.
(HIGH)
IC6B
LPF
MOD2
TXE
RXE
5 x 10K
RD
UART
TD
PTT
CTS
TXD
D/V
L.D.
CH D
CLK
CH B
DATA
CH C
L.E.
CH A
UART
CHANNEL
SQUELCH
X1
CV1
+ 5R
XTAL
FILTER
Q3
MIXER
RF
SAW
BPF
LPF
-10 dBm
RX
S5
SQUELCH
+5V
D7
B
A
IC10
+5V