Radio Shack PRO-197 User manual

PRO-197
Digital Trunking Base/Mobile Scanner
Catalog Number: 20-197
CONTENTS
Page
Specifications .................................................................................................................................................... 2
Block Diagram ................................................................................................................................................... 4
Alignment and Adjustment ................................................................................................................................ 5
Troubleshooting ............................................................................................................................................... 10
Printed Circuit Board ....................................................................................................................................... 15
Wiring Diagram ................................................................................................................................................ 20
Exploded View ................................................................................................................................................. 21
Mechanical Parts List ....................................................................................................................................... 22
Electrical Parts List .......................................................................................................................................... 24
Semiconductor Lead Identification ................................................................................................................. 66
Microprocessor (IC306) Port Format............................................................................................................... 72
Schematic Diagram ......................................................................................................................................... 73
© 2008 RadioShack Corporation
All Rights Reserved.
RadioShack is a registered trademark used by RadioShack Corporation.
20-197

2
SPECIFICATIONS
Frequency Coverage 25.000-26.960 MHz 10 kHz steps (AM)
26.965-27.405 MHz 10 kHz steps (AM)
27.410-29.505 MHz 5 kHz steps (AM)
29.510-29.700 MHz 5 kHz steps (FM)
29.710-49.830 MHz 10 kHz steps (FM)
49.835-54.000 MHz 5 kHz steps (FM)
108.000-136.99166 MHz 8.33 kHz steps (AM)
137.000-137.995 MHz 5 kHz steps (FM)
138.000-143.9875 MHz 12.5 kHz steps (FM)
144.000-147.995 MHz 5 kHz steps (FM)
148.000-150.7875 MHz 12.5 kHz steps (FM)
150.800-150.845 MHz 5 kHz steps (FM)
150.8525-154.4975 MHz 7.5 kHz steps (FM)
154.515-154.640 MHz 5 kHz steps (FM)
154.650-156.255 MHz 7.5 kHz steps (FM)
156.275-157.450 MHz 25 kHz steps (FM)
157.470-161.5725 MHz 7.5 kHz steps (FM)
161.600-161.975 MHz 5 kHz steps (FM)
162.000-174.000 MHz 12.5 kHz steps (FM)
216.0025-219.9975 MHz 5 kHz steps (FM)
220.000-224.995 MHz 5 kHz steps (FM)
225.000-379.99375 MHz 6.25 kHz steps (AM)
380.000-419.9875 MHz 12.5 kHz steps (FM)
420.000-450.000 MHz 5 kHz steps (FM)
450.00625-469.99375 MHz 6.25 kHz steps (FM)
470.000-512.000 MHz 12.5 kHz steps (FM)
764.000-805.996875 MHz 3.125 kHz steps (FM)
806.000-823.9875 MHz 12.5 kHz steps (FM)
849.000-868.9875 MHz 12.5 kHz steps (FM)
894.000-939.9875 MHz 12.5 kHz steps (FM)
940.000-960.000 MHz 6.25 kHz steps (FM)
1240.000-1300.000 MHz 6.25 kHz steps (FM)
Unit Nominal Limit
Signal to noise ratio (FM and AM)
RF input: 100 μV 25-54 MHz dB 40 30
Dev. 3 kHz at 1 kHz 108-136.99166 MHz dB 40 30
Mod.: 60% at 1 kHz 137-174 MHz dB 40 30
216.0025-299.99375 MHz dB 40 30
300-512 MHz dB 35 25
764-960 MHz dB 35 25
1240-1300 MHz dB 35 25
Squelch sensitivity
at threshold (AM/FM) μV 0.5 2
at tight (FM) dB 25 15
at tight (AM) dB 20 10
Data decode sensitivity
WX Alert 1050 Hz tone 3 kHz Dev. at 162.4 MHz μV 0.3 1

3
Unit Nominal Limit
Signal Stalker II sensitivity at 450 MHz dBm -60 -50
Sensitivity
FM: (S+N)/N=20 dB 25-54 MHz μV 0.3 1
Dev.: 3 kHz at 1 kHz 108-136.99166 MHz μV 0.3 1
137-174 MHz μV 0.5 2
216.0025-224.995 MHz μV 0.5 2
225-299.99375 MHz μV 0.5 2
300-405.9875 MHz μV 0.8 3
406-512 MHz μV 0.5 2
764-960 MHz μV 0.7 3
1240-1300 MHz μV 0.7 4
AM: (S+N)/N=20 dB 25-54 MHz μV13
Mod.: 60% at 1 kHz 108-136.99166 MHz μV13
137-174 MHz μV 1.5 5
216.0025-224.995 MHz μV 1.5 5
225-299.99375 MHz μV26
300-405.9875 MHz μV310
406-512 MHz μV26
764-960 MHz μV26
1240-1300 MHz μV312
Selectivity AM 25-27.995 MHz -6 dB kHz ±4 >±2.5
-50 dB kHz ±6 <±12
Other frequency -6 dB kHz ±7 >±4.5
-50 dB kHz ±13 <±18
Spurious rejection (Except Primary image) at 154.1 MHz dB 40 30
Acceptable radio frequency displacement (EIA RS-204D) kHz ±6 ±3
Residual noise Volume control, set to its minimum, squelched mV 2 5
Scanning rate without trunking channels/sec. 55 45-66
Search rate at 162.25-167.25 MHz steps/sec. 90 80-100
Scan delay time Default setting sec. 2 1-3
Audio output power 10% THD W 1.5 1.0
Working memory 1,800 programmed object using flexible scannable object system
Display Liquid crystal display (16-charactor x 4-line, plus icon)
Receiving system Triple conversion PLL super-heterodyne,
1st IF: 380.8 MHz/2nd IF: 21.4 MHz/3rd IF: 455 kHz
Power source 13.8V DC negative ground only
Jacks Antenna, earphone, PC/IF, external speaker, and power
Dimensions (HWD) 2 1/4 x 7 1/4 x 5 5168 inches (55 x 185 x 135 mm)
Weight apporox. 42.3 oz. (1200 g) without antenna and batteries
Note: Nominal specs represent the design specs. All units should be able to approximate these specifications.
Some units will exceed while some may drop below these specs. Limit specs represent the absolute worst condition
still considered acceptable. A unit should NEVER fail to meet limit specs.

BPF
Attenuator
D1,D2
RF Amp
Q7
RF Amp
Q3,Q4
1st Mix
IC2
2nd Mix
Q9
2nd IF Amp
Q10
Noise Amp
IC6a
Ceramic
Filter
CF1
AGC Amp
Q11
AM/FM
Switching
IC9a,9b,10a,10d
Pre Amp
IC8a
Mute
IC10b,Q32
Audio Amp
IC11
Voltage
Regulator
IC12
Regulator
Switching
IC13
DC-DC
Converter
IC5
AGC Amp
Q8
Switching
Q5,Q6
Switching
Q2
Band Select
Att. Control
IC1
Switching
Q21
VCO1
Q20
VCO2
Q22
Switching
Q23
Buffer
Amp
Q24
PLL
IC4
Low-Pass
Filter
Q25,Q26
Buffer
Amp
Q30
VCO3
Q29
Low-Pass
Filter
Q27,Q28
LCD
Keyboard
CPU
IC307
Voltage
Detector
IC303
Memory
IC301
SAME Data
Filter
IC306c,d
WX Alert Data
Filter
IC306a,b
Hi Speed Data
Filter
IC305a
Low Speed
Data Filter
IC304,305b
Oscillator
IC4
3rd IF Amp Noise Amp
3rd Local Mixer
Quadrature Detector
IC7
Buffer Amp
IC8b
PWR
DC
13.8V
J1
J3
Ceramic
Filter
CF2
Filter
Switching
Q31
25-54MHz
108-225MHz
225-406MHz
406-512MHz
764-1300MHz
1st IF
(380.650-380.86875MHz)
XF 1
2nd IF
21.4MHz
XF 2
X2
20.945MHz
455kHz
3.3V
12.75MHz
X 1
11.0592MHz
X301
PLL Data
SQ IN
Filter SW
FM/AM/Digital
Mute
Keytone
3.3V
Data
Cont.Data
1st
Local
2nd
Local
Zeromatic
Switching
Q1
Switching
Q14,D23
Switching
Q13,Q17
2nd IF Amp
Q15,Q16
Detector,
Comparator
D27,28,IC3
SQ 2
B+ (8V)
LED Driver
Q302,303
304,306,307
LED
Reset
Q305
Switching
Q12
Scan Cont.
Search Cont. LD
Switching
Q18,Q19
ANT
DSP
IC310
Flash
Memory
IC311
CODEC
IC313
Voltage
Regulator
IC309
Voltage
Regulator
IC308
Shift
Resister
IC312
3rd Local
Swithing
IC9c,9d
3rd Local Cont.
Voice
X302
18.432MHz
SQUELCH
VOLUME
PC/IF
J201
Power SW
VR201
VR202
J202
J2 EXT SPK
Speaker
4
BLOCK DIAGRAM

5
ALIGNMENT AND ADJUSTMENT
ALIGNMENT AND TEST POINT
ALIGNMENT PREPARATION
Test Equipment Required
zOscilloscope
zDC SSVM
zFM signal generator
zFrequency counter (800 MHz)
Notes:
zUse non-metallic tuning tools.
zThe test equipment and receiver should be warmed up for at least 10 minutes before proceeding with alignment.
zThe signal level from the generator should be kept as low as possible to obtain a usable output.
zTo tune the frequency, press TUNE, frequency number including decimal point, then press ENT.
If you make a mistake, press CL to delete a single digit or hold CL about 2 seconds to start over.
Main PCB
TP1
TP6 TP4 TP5
T4
VR1
VR4
VR3
VR2
VR5
TC1
L24
L23
L26
L18
TP2
TP3

6
ALIGNMENT PROCEDURES
PLL2 VCO Alignment
PLL1 VCO1 Alignment
PLL1 VCO2 Alignment
Table 1
Figure 1 Figure 2
DC SSVM
TP2Unit
Under Test
DC SSVM
TP3Unit
Under Test
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7
Adjustment of Coils L23, L24, and L26
Notes:
zBe very careful when doing coil pitch adjustment
because it greatly affects the frequency.
zSecure the coil with glue after alignment. Be sure
the glue is dry and the coil is secured. Also, be
sure that the environmental temperature is nor-
mal. Then, repeat VCO (PLL2 and PLL1) align-
ments on Page 6.
Each coil should be adjusted carefully by changing the
pitch of the coil little by little using a non-metallic tuning
tool as shown in Figure 3.
Increase the pitch of the coil when the measured volt-
age at TP2 or TP3 is higher than the voltage listed in
Table 2 for the PLL2 VCO alignment, PLL1 VCO1 align-
ment, and PLL1 VCO2 alignment.
Decrease the pitch of the coil when the measured volt-
age at TP2 or TP3 is lower than the voltage listed in Table
2 for the PLL2 VCO alignment, PLL1 VCO1 alignment,
and PLL1 VCO2 alignment.
Figure 3
Table 2
Reference Frequency Osc. Confirmation
Note: Care should be taken not to make any contact between TP1 and the shield case.
455 kHz FM Discriminator Coil Alignment
Figure 4
Figure 5
Use
non-metallic
tuning tool
PCB
Coil
Frequency Counter
TP1
Unit
Under Test
FM Signal
Generator
ANT. Jack
Unit
Under Test
DC SSVM
TP4
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8
3rd Local Alignment
Frequency Counter
TP5
Unit
Under Test
ANT
FM Singal Generator
IF (380.8 MHz) Trap Adjustment
FM Signal
Generator
ANT. Jack
Unit
Under Test
Oscilloscope
8-
ohm
Headphone
Jack
Figure 7
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9
Signal Meter Alignment
Figure 8
FM Signal
Generator Unit
Under Test
TP6
ANT. Jack
DC SSVM
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Power ON
Is the display
normal?
Is EEPROM check
program OK? Defective IC301.
Defective IC307, LCD
and/or associated
circuit.
Is the voltage
of TP2 about 18 V at
960 MHz?
Defective
PLL circuit
(IC4) or
VCO
circuit.
Proceed to Microprocessor
check.
NO
NO
NO
YES
YES
YES
Power on the scanner.
Press 0while the scanner shows -Welcom To-
Object Oriented Digital Trunking RadioShack.
The scanner shows System Tests: Select a
Test... Exits if no key is pressed. Then press 5.
The scanner shows EEPROM Test Erase
Momory ENTER if APPROVE CLEAR to EXIT.
Then press ENT.
The scanner shows Testing, and automatically
starts the EEPROM test program.
The scanner initializes the working memory.
Is the voltage
of TP2 about 20 V at
1300 MHz?
Is the voltage
of TP3 about 2.0 V at
512 MHz?
YES
YES
NO
NO
EEPROM check program
procedure as follows:
Note: This procedure clears all information you
stored in the scanner's working memory.
TROUBLESHOOTING
Reception Check
10
Does the
display work
properly?
NO
YES
Does display
freeze showing Waiting
for DSP or DSP
Loder ....
NO
Proceed to DSP
section (Boot
section) check.
YES
The scanner shows GLOB EEPROM area
initialized to defaults. Press any key. Then press
any key.
The scanner shows Initializing the File system
then File system initialized to defaults. Press any
key. Then press any key.