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
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
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—
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
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
Loading...