Operating instructions

1 2 3 4 5 6
A B C D
6
54321
D
C B A
Title
Number RevisionSize
Orcad B
Date: 7-Aug-1998 Sheet of
File: D:\RFT_MasterFiles\..\9131-RxUHF-block.schDrawn By:
45 MHz
600 MHz
U4
250Hz
Q10-Q16
Fx
Flo = Fx - 45
+13 dBm
Flo
45 MHz
RSSI
12.8
MHz
NOISE FILTER
H1
CTCSS
DECODER
MODULE
TONE DETECT SUB-TONE OUT NOISE DETECT
+ -
LINE OUT LINE OUT
MONITOR AMP.
LINE AMP.
750 uSec
MICROPROCESSOR CONTROLER
U7,U11-U16
A/D
RSSI
TUNE V.
CARRIER SQ.
+13.8
DATA
LOCK DETECT
TONE DATA
SQUELCH
COS+ COS-
ISO1
NOISE DETECT TONE DETECT TONE DATA
ASYNC.
DATA I/O
Rx DATA Tx DATA
BCD CHANNEL CODE
1 PPM TCXO
PLL IC
STEPS
LOOP FILTER
HELICAL FILTER
2 RESONATOR RF AMP. 4 RESONATOR
HELICAL FILTER
DOUBLE BAL.
MIXER
1st IF AMP. 2nd IF AMP. 455 KHz AMP. BPFBPFXTAL FILTERXTAL FILTER
LIMITER
/DISCRIMINATOR AUDIO AMP.
RSSI BUFFER
LPF
LPF HPF
VCO ISOLATION AMPS
LO AMPLIFIER
+15 dBm
LO OUTPUT
2nd MIXER
2nd OSC.
12.5/10 KHz
EXT. SQ. *
* NOT ON PCB 30/9101
BNC
FL1 Q1 FL2, FL3
MX1
Q2,Q3 XF1
C45,C46,L13
Q5MA2 MA1
MA3 MA4
Q4 XF2
U1
Y1
45.455 MHz
CF1
455 KHz
CF2
455 KHz
U3B U2B
U2A
U27B 4 KHz
U26
300 Hz
XO1
U28A,B
250 Hz
U27A 10 KHz
D6,Q17,U17D,U26C
NOISE DETECTOR
U27D
NOISE AMP.
U17A
SW SPST
U5
T1
TRANSFORMER
U22A,B
U27C
DE-EMPHASIS
U17B
SW SPST
S1 SW SPST
SQ.
ALM
Q6,Q7
VCO
Q27*, U3A
R F Technology
17/8 Leighton Place, Hornsby, Sydney, 2077 Australia
11/9131/0001 UHF Rx Rev 1
JBS after RHM
21