Page 1
Service Manual
TRC- 9A/1 1
3
-
CHANNEL /6-CHANNEL C.B.
MOBILE TRANSCEIVER
Catalog Number:
21 - 139/141
CUSTOM MANUFACTURED FOR RADIO SHACK A TANDY CORPORATION COMPANY
Page 2
CONTENTS
Page
1.
SPECIFICATIONS
1
2.
CRYSTAL LOCATIONS
1
3.
CHASSIS DISASSEMBLY
2
4.
GENERAL ALIGNMENT INSTRUCTIONS
3,4
5.
ALIGNMENT POSITION
4
6.
BLOCK DIAGRAM
5
7.
WIRING DIAGRAM
5
8.
P.C. BOARD (TOP VIEW)
6
9.
P.C. BOARD (BOTTOM VIEW)
6
10.
TROUBLE SHOOTING
7
11.
PARTS LIST
8-12
12.
SUB P.C. BOARD
12
13.
SUB P.C. BOARD PARTS LIST
13
14.
SEMICONDUCTOR LEAD IDENTIFICATION
13
15.
SCHEMATIC DIAGRAM FOR SUB P.C.BOARD
13
16.
SCHEMATIC DIAGRAM (TRC-9A)
14
17.
SCHEMATIC DIAGRAM (TRC-11)
15
Page 3
TRC-9A
TRC-11
SPECIFICATIONS
Description
Nominal spec.
Limit spec.
Frequency range
26.965-27.255 MHz
Channels
3 channels TRC-9A (21-139)
6 channels TRC-11 (21-141)
Frequency tolerance
Less than ±0.005%
Operating voltage
13.8VDC
-
±10%
Sensitivity
0.70/ at 10 dB
1.50 at 10 dB
Selectivity
—33 dB at ±10 kHz
—30 dB at 10 KHz
Intermediate frequency
455 kHz with ceramic filter
Signal to noise ratio
More than 40 dB at 1mV input
Squelch sensitivity
Threshold less than 1AV
Tight 50AV-3mV
Tight 5000
Audio output
1.2 watts,
More than 0.8 watt
Max. power 10% distortion
More than 0.65 watt
1 watt
RF output
3 watts
2.5 watts
Power input
5 watts max.
Modulation
Below 100%
Antenna impedance
50 ohms (unbalanced)
Speaker impedance
8 ohms, 2-1/4" Dynamic type
Dimensions
4-1/4"(W) x 6-1/2" (D) x 1-3/4" (H)
CRYSTAL LOCATIONS
—1—
Page 4
CHASSIS DISASSEMBLY
Removal of the cavinet:
Step 1:
Remove 2 mounting braCket screws(A) as shown
and remove the mounting bracket.
Step 2:
Remove 2 screws(B) as shown from the rear.
Step 3: Pull
out the chassis from the front.
Page 5
GENERAL ALIGNMENT INSTRUCTIONS
Test equipment required
1 RF standard signal generator (S.S.G.)
2 AF signal generator
3 V.T.V.M.
4 RF power meter
5 Oscilloscope
6 Monitor receiver
7 Frequency counter
8 1A DC ammeter
9 8 ohm dummy load
Note: Keep the input signal from S.S.G. as low as possible during all alignment.
RECEIVING SECTION ALIGNMENT CHART
STEP
CONTROL
SETTING
TEST
EQUIPMENT
CONNECTION
SIGNAL
GENERATOR
SETTING
ADJUST
REMARKS
1
Volume control:
Fully clockwise
SQ control:
Max. counterclockwise
CH: A position
27.065 MHz
(TRC-9A)
27.085 MHz
(TRC-11)
V.T.V.M.:
Parallel with 8 ohm
dummy load connected
to J2
Signal generator:
through 100 pF to the
base of Q2 2SC371
Freq: 455 kHz
Mod.: 1 kHz 30%
T3 (YEL)
T4 (WHT)
T5 (B LK)
Max. output on
voltmeter
2
fl
V.T.V.M.:
Parallel with 8 ohm
dummy load connected
to J2
Signal generator:
to J1
Freq.: 27.065MHz
(TRC-9A)
27.085MHz
(TRC-11)
Mod.: 1 kHz
T1, 2
Max. output on
voltmeter
3
Volume control:
Adjust for desired
audio level
SQ. Control:
Fully clockwise
V.T.V.M.:
Parallel with 8 ohm
dummy
load or across
speaker to
J2
Signal generator to J1
Freq.: 27.065MHz
' (TRC-9A)
27.085MHz
(TRC-11)
Mod.: 1kHz 30%
Output: 500µV
R34
Adjust so squelch
just opens
Page 6
TRANSMITTING SECTION ALIGNMENT CHART
STEP
CONTROL
SETTING
TEST
EQUIPMENT
CONNECTION
TEST
EQUIPMENT
SETTING
ADJUST
REMARKS
1
CH: A position
27.065MHz
(TRC-9A)
27.085MHz
(TRC-11)
Power meter (50 ohms):
to J1
1A ammeter:
in series with lead between
modulation winding of
T8 and collector of Q14
Oscilloscope:
in parallel with power
meter
Supply voltage:
13.8 volts
2
Press the P.T.T. SW.
"
II
T9, 10
Max. power output
3
,,
„
„
L5, 6
Peak on the Power
meter and dip on the
ammeter to get 3
watts output at J1
(or max output)
4
"
Power meter (50 ohms):
to J1
1 A ammeter:
in series with lead between
modulation winding of
T8 and collector of Q14.
Vary supply voltage
from 15 to 12 volts.
T9
If no output, adjust
T-9 to assure output
at both voltage
extremes.
5
"
Audio frequency generator:
to C23 (or talk into
Microphone).
Reset the supply
voltage to 13.8 volts.
Check modulation
6
Repeat steps 2 to 4.
ALIGNMENT POSITION
=]=1
fl
9
T7
—4—
Page 7
TX XTAL
Q12
TX OSC
Q13
DRIVER
Q14
FINAL
BLOCK DIAGRAM
ANT.
Q1
RF
RX XTAL
Q2
MIX.
Q5
RX OSC
Q3
1st IF
Q7
Q4
2nd IF
D3, D4
DET. ANL
VOL
SQ
SQ
Q10
AF POWER
Q6
Q8
Q9
MIC
MIC. AMP
AF
AF
Q11
AF POWER
TRC-9A and TRC-11
WIRING DIAGRAM
Note: 6 crystal sockets with lead wires (wires color BRN,RED and ORG.) are TRC-9A.
—5—
Page 8
P. C. BOARD (TOP VIEW)
*1
R64 is used for TRC-11 only.
* *2
Crystal socket D, E and F used for TRC-11 only.
P.C. BOARD (BOTTOM VIEW)
Page 9
TROUBLE SHOOTING
Symptom
Possible cause
1) Pilot lamp and channel indicator (TRC-11 only)
lamps do not light and set does not operate when
power is on.
A)
Faulty power cord.
B)
Defective power switch SW2.
C)
2A fuse blown.
2) Fuse blows when power switch is on.
A)
Defective Electrolytic capacitor.
B)
Defective audio power
amplifier transistor
Q10
or
Q11.
C)
Defective TX final Transistor Q14 or Q13.
D)
Defective zener diode D7.
3) Pilot lamp or channel indicator lamp (TRC-11
only) does not light.
A)
Defective pilot lamp or resistor R63.
B)
(TRC-11 only) Defective channel indicator lamp or
resistor R64.
C)
Short circuit in the B+ Circuit.
4) Pilot lamp comes on but no sound on any channel.
A)
Faulty EXT. Speaker jack J2.
B)
Poor crystal socket contact or crystal loose in socket.
C)
Defective zener diode D5.
D)
Weak crystal.
5) Transmitter does not operate or no modulation.
A)
Faulty P.T.T. switch.
B)
Defective microphone cartridge.
C)
Faulty transistor Q12, 13, or Q14.
D)
Faulty microphone cord.
E)
Defective T8 Transformer modulation winding.
F)
Defective resistor R57 or R59.
G)
Faulty transistor Q6 or Q7,
6) Squelch control does not operate.
A)
Defective transistor Q7.
B)
Faulty VR2 or R34.
Page 10
SUB P.C. BOARD WIRING DIAGRAM
(TOP VIEW)
(BOTTOM VIEW)
FOR CANADIAN/D.O.C. MODELS ONLY
SUB P.C. BOARD
NOTE: Modulation limiting stage for Canadian model TRC-9A and TRC-11
Yellow
Black
Ref. No.
Description
RS Parts Number
MFR's Parts Number
Channel switch Knob (TRC-11 only)
K-1074
GE-18D-4433
Lamp 1
Pilot Lamp 7V 50mA L=190mm
L-0263
Lamp 2
Channel indicator lamp (TRC-11 only)
L-0263
7V 50mA L=190mm
Lamp Jewel
HB-0706
GE-17D-3438
Lamp Holder (TRC-11 only)
LH-141
Fuse 2A
P.C. Board
X-4269
GE-18C-4305
J1
Antenna jack connector
J-6244
SO-239 273
J2
Speaker Jack
J-0592
JA-C-011
SPK
Speaker
S-4335
P0642AA
Line cord strain relief
HB-0705
SR-3P-4
Rubber bushing
GE-15D-2699
Rubber bushing (New type)
GE-19D-4607
Page 11
SUB P.C. BOARD PARTS LIST
(Modulation limiting stage for Canadian model TRC-9A and TRC-11)
Ref. No.
Description
RS Parts Number
MFR's Parts Number
CAPACITORS
C62
C63
C64
Electrolytic
4.7 AF/16WV
Ceramic
0.001µF
Ceramic
0.04µF
CE04W IC470B
MC-60
MC-100
RESISTORS
R66,
69
R67
R68
Carbon film
10KS2
1/4W
± 5%
Carbon film
47K2
1/4W
± 5%
Carbon film
1K2
1/4W
± 5%
ELR 1/4 103J
ELR 1/4 473J
ELR 1/4 102J
SEMICONDUCTORS
Q15
D10
Transistor. Silicon, Toshiba
Diode,
Silicon
2SC373
1N60
MISCELLANEOUS
P.C. Board
GE-19D-4788
Page 12
1.
SW1a-b:
CHANNEL SW.
2.
SW2:
POWER SW W/VR1
3.
RESISTANCE VALUES IN OHMS.
K=1000
4.
CAPACITANCE VALUES IN MF.
P=MMF
5.
VOLTAGES ARE MEASURED WITH V.T.V.M.
UNDER FOLLOWING CONDITIONS:
VOLUME MINIMUM
SQUELCH MAXCLOCKWISE.
TRC-9A
CAT.No. 21-139
Page 13
NOTE:
1.
SW1a-b:
CHANNEL SW.
2.
SW2:
POWER SW W/VR1 VOL. CONT.
3.
RESISTANCE VALUES IN OHMS
unless otherwise
indicated
(K=1000).
4.
CAPACITANCE VALUES IN MF
unless otherwise
indicated (P=MMF).
5.
VOLTAGES ARE MEASURED WITH
V.T.V.M. UNDER FOLLOWING CONDITIONS:
VOLUME MINIMUM
SQUELCH MAX. CLOCKWISE.
TRC-11
CAT.No. 24-141
Page 14
RADIO SHACK Q A TANDY CORPORATION COMPANY
U.S.A.: FORT WORTH, TEXAS 76107
CANADA: BARRIE, ONTARIO, CANADA L4M 4W5
TANDY CORPORATION
AUSTRALIA
BELGIUM
280-316 VICTORIA ROAD
PARC INDUSTRIEL DE NANINNE
BILSTON ROAD
RYDALMERE, N.S.W. 2116
5140 NANINNE
WEONESBURY, STAFFS WF10 7JN
6A4-4000
Printed in Japan
U. K.
Loading...