Service Manual
TRC9A/1 1
3-CHANNEL /6-CHANNEL C.B.
MOBILE TRANSCEIVER
Catalog Number: 21 - 139/141
CUSTOM MANUFACTURED FOR RADIO SHACK A TANDY CORPORATION COMPANY
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CONTENTS |
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Page |
1. |
SPECIFICATIONS |
1 |
2. |
CRYSTAL LOCATIONS |
1 |
3. |
CHASSIS DISASSEMBLY |
2 |
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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 |
SPECIFICATIONS
Description |
Nominal spec. |
Limit spec. |
Frequency range |
26.965-27.255 MHz |
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Channels |
3 channels TRC-9A (21-139) |
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6 channels TRC-11 (21-141) |
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Frequency tolerance |
Less than ±0.005% |
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Operating voltage |
13.8VDC ±10%- |
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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 |
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Signal to noise ratio |
More than 40 dB at 1mV input |
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Squelch sensitivity |
Threshold less than 1AV |
Tight 50AV-3mV |
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Tight 5000 |
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Audio output |
1.2 watts, |
More than 0.8 watt |
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Max. power 10% distortion |
More than 0.65 watt |
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1 watt |
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RF output |
3 watts |
2.5 watts |
Power input |
5 watts max. |
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Modulation |
Below 100% |
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Antenna impedance |
50 ohms (unbalanced) |
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Speaker impedance |
8 ohms, 2-1/4" Dynamic type |
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Dimensions |
4-1/4"(W) x 6-1/2" (D) x 1-3/4" (H) |
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CRYSTAL LOCATIONS
TRC-9A |
TRC-11 |
—1—
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.
GENERAL ALIGNMENT INSTRUCTIONS
Test equipment required
1 RF standard signal generator (S.S.G.)
2 AF signal generator
3V.T.V.M.
4RF power meter
5Oscilloscope
6Monitor receiver
7Frequency counter
81A DC ammeter
98 ohm dummy load
Note: Keep the input signal from S.S.G. as low as possible during all alignment.
RECEIVING SECTION ALIGNMENT CHART
CONTROL
STEP
SETTING
Volume control:
Fully clockwise
SQ control:
Max. counter-
1 clockwise CH: A position
27.065 MHz
(TRC-9A)
27.085 MHz (TRC-11)
fl
2
Volume control:
Adjust for desired
3 audio level SQ. Control:
Fully clockwise
TEST
EQUIPMENT
CONNECTION
V.T.V.M.:
Parallel with 8 ohm dummy load connected to J2
Signal generator: through 100 pF to the base of Q2 2SC371
V.T.V.M.:
Parallel with 8 ohm dummy load connected to J2
Signal generator: to J1
V.T.V.M.:
Parallel with 8 ohm dummy load or across
speaker to J2
Signal generator to J1
SIGNAL |
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GENERATOR |
ADJUST |
REMARKS |
SETTING |
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Freq: 455 kHz |
T3 (YEL) |
Max. output on |
Mod.: 1 kHz 30% |
T4 (WHT) |
voltmeter |
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T5 (B LK) |
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Freq.: 27.065MHz |
T1, 2 |
Max. output on |
(TRC-9A) |
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voltmeter |
27.085MHz |
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(TRC-11) |
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Mod.: 1 kHz |
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Freq.: 27.065MHz |
R34 |
Adjust so squelch |
' (TRC-9A) |
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just opens |
27.085MHz |
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(TRC-11) Mod.: 1kHz 30% Output: 500µV
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