Realistic RadioShack TRC-9A Service Manual

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

SPECIFICATIONS

1.
CRYSTAL LOCATIONS

2.
CHASSIS DISASSEMBLY

3.
GENERAL ALIGNMENT INSTRUCTIONS

4.

5.

ALIGNMENT POSITION

6.

BLOCK DIAGRAM

7.

WIRING DIAGRAM

8.

P.C. BOARD (TOP VIEW)

9.

P.C. BOARD (BOTTOM VIEW)

10.

TROUBLE SHOOTING

11.

PARTS LIST

12.

SUB P.C. BOARD

13.

SUB P.C. BOARD PARTS LIST

14.

SEMICONDUCTOR LEAD IDENTIFICATION

SCHEMATIC DIAGRAM FOR SUB P.C.BOARD

15.

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3,4

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8-12

12

13
13

1
1
2

4

5
5
6
6
7

13

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SCHEMATIC DIAGRAM (TRC-9A)

16.
SCHEMATIC DIAGRAM (TRC-11)

17.





14
15

SPECIFICATIONS

Description

Frequency range
Channels

Frequency tolerance
Operating voltage
Sensitivity
Selectivity

Intermediate frequency
Signal to noise ratio
Squelch sensitivity

Audio output

RF output

Power input

Modulation

Antenna impedance

Speaker impedance

Dimensions

Nominal spec.

26.965-27.255 MHz
3 channels TRC-9A (21-139)

6 channels TRC-11 (21-141)
Less than ±0.005%

-

13.8VDC

0.70/ at 10 dB
—33 dB at ±10 kHz
455 kHz with ceramic filter
More than 40 dB at 1mV input
Threshold less than 1AV

Tight 5000

1.2 watts,

Max. power 10% distortion

1 watt
3 watts

5 watts max.
Below 100%
50 ohms (unbalanced)

8 ohms, 2-1/4" Dynamic type
4-1/4"(W) x 6-1/2" (D) x 1-3/4" (H)

±10%

Limit spec.

1.50 at 10 dB
—30 dB at 10 KHz

Tight 50AV-3mV

More than 0.8 watt
More than 0.65 watt

2.5 watts

CRYSTAL LOCATIONS

TRC-9A

TRC-11

—1—

CHASSIS DISASSEMBLY

Removal of the cavinet:
Step 1:

Step 2:
Step 3: Pull

Remove 2 mounting braCket screws(A) as shown
and remove the mounting bracket.
Remove 2 screws(B) as shown from the rear.

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

1

2

3

CONTROL

SETTING

Volume control:

Fully clockwise

SQ control:

Max. counter­clockwise

CH: A position

27.065 MHz
(TRC-9A)

27.085 MHz

(TRC-11)

fl

Volume control:

Adjust for desired

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

speaker to

Signal generator to J1

load or across

J2

SIGNAL

GENERATOR

SETTING

Freq: 455 kHz
Mod.: 1 kHz 30%

Freq.: 27.065MHz

(TRC-9A)

27.085MHz
(TRC-11)

Mod.: 1 kHz

Freq.: 27.065MHz

' (TRC-9A)

27.085MHz

(TRC-11)
Mod.: 1kHz 30%
Output: 500µV

ADJUST

T3 (YEL)
T4 (WHT)
T5 (B LK)

T1, 2

R34

REMARKS

Max. output on
voltmeter

Max. output on
voltmeter

Adjust so squelch

just opens