/Si g7C2
SerViCe- HUI
1110111111.111111MIIMtionleadommookup4
TRC-449
CB TRANSCEIVER
Catalog Number: 21-1562
CUSTOM MANUFACTURED FOR RADIO SHACK M A DIVISION OF TANDY CORPORATION
TABLE OF CONTENTS
1. SPECIFICATIONS |
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3 5 |
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2. |
DISASSEMBLY INSTRUCTIONS |
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6 |
3. |
BLOCK DIAGRAM |
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7 |
4. |
ALIGNMENT INSTRUCTIONS |
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8 16 |
5. |
TROUBLESHOOTING HINTS |
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17 - 18 |
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6. |
PLL CIRCUIT TROUBLESHOOTING HINTS |
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19 |
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7. |
IC. TRANSISTOR & DIODE LEAD IDENTIFICATIONS |
20 |
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8. |
IC & COMPOUND PARTS INTERNAL DIAGRAMS |
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21 |
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9. |
CHANNEL SWITCH P.C. BOARD (FLEXIBLE) |
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22 |
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10. |
NOISE BLANKER P.C. BOARD |
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22 |
11. |
SPEAKER JACK P.C. BOARD (TOP & BOTTOM) |
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22 |
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12. |
MAIN P.C. BOARD (TOP VIEW) |
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23 |
13. |
MAIN P.C. BOARD (BOTTOM VIEW) |
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24 |
14. |
ADDITIONAL PARTS ON THE BOTTOM |
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25 |
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15. |
WIRING DIAGRAM |
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26 |
16. |
WIRING DIAGRAM |
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27 |
17. |
WIRING DIAGRAM |
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28 |
18. |
ELECTRICAL PARTS LIST |
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29 - 42 |
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19. |
MECHANICAL PARTS LIST |
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43 45 |
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20. |
SCHEMATIC DIAGRAM |
(SEPARATE SHEET) |
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21. |
EXPLODED VIEW |
(SEPARATE SHEET) |
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1. SPECIFICATIONS
GENERAL:
Channels
Frequency Range
Frequency Control
Frequency Accuracy
Operating Temperature Range
Power Requirements
Antenna
Microphone
Speaker
Size
Weight
Accessories
:40 Channels for AM, Upper Side Band and Lower Side Band, utilizing Digital Circuitry
:26.965 MHz to 27.405 MHz
:Digital (Phase Lock Loop) Synthesizer
:±100 Hz
:-20°C to +50°C
:13.8V DC (12-16 volts DC, negative or positive ground)
:52 ohm (Coaxial connector)
:600 ohm Dynamic Type
:8 ohm, 3 Watt
:2-3/8" x 7-7/8" x 10-1/2" (HWD) (6 x 20 x 26.6 cm [HWD] )
:6 lbs. (approx.) (2.65 kg)
:DC Cord with in-line Fuse, Microphone and Microphone Hanger and Mounting Brackets
MEASUREMENT CONDITION
Power Source
Antenna Impedance
Test Temperature
AM Modulation Frequency
SSB Modulation Frequency, Transmit
Mean Signal Input Level
Reference Audio Output Power
Reference AM Modulation Percentage
Audio Frequency, SSB Receive
Audio Output Load
Measuring Channel
:13.8V DC
:50 ohm
:25° C
:1 kHz
Two tone: 500 Hz and 2400 Hz Single tone: 1 kHz
:1000 btV
:0.5 W
:1 kHz 30%
:1 kHz
:8 ohms resistive
•19
RECEIVER : (ANL fiti Noise Blanker Switch OFF) |
UNIT |
NOMINAL |
LIMIT |
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Max. Sensitivity |
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: AM |
µV |
0.5 |
1 |
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SSB |
,uV |
0.25 |
0.5 |
Sensitivity for 10 dB S/N |
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: AM |
µV |
0.5 |
1 |
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SSB |
pV |
0.25 |
0.5 |
AGC Figure of Merit 50 mV for |
:AM |
dB |
90 |
80 |
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10 dB Change in Audio Output |
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SSB |
dB |
90 |
80 |
Overload AGC Characteristics from |
: AM |
dB |
±3 |
±5 |
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10 mV to 100 mV |
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SSB |
dB |
±3 |
±5 |
Overall Audio Fidelity at 6 dB Down |
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Upper Frequency |
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: AM |
Hz |
2100 |
1750 — 2500 |
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SSB |
Hz |
3500 |
2500 — 5000 |
Lower Frequency |
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: AM |
Hz |
450 |
300 — 650 |
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SSB |
Hz |
450 |
300 — 650 |
Cross Modulation, RS Standard |
: AM |
dB |
60 |
50 |
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Adjacent Channel Selectivity (10 kHz) |
:AM |
dB |
65 |
54 |
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SSB |
dB |
65 |
54 |
Maximum Audio Output Power |
:AM |
W |
4 |
3 |
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SSB |
W |
4 |
3 |
Audio Output Power at 10% THD |
:AM |
W |
3 |
2.5 |
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SSB |
W |
3 |
2.5 |
THD at 500 mW Audio Output |
: AM |
% |
3 |
6 |
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AM: 1 mV Input, 30% modulation |
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80% modulation |
: AM |
% |
5 |
12 |
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SSB: 1 mV Input 1 kHz Single tone |
: SSB |
% |
3 |
6 |
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RF Gain Control Range at Max. |
: AM |
dB |
40 |
30 — 50 |
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Sensitivity Level |
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SSB |
dB |
40 |
30 — 50 |
S/N Ratio at Input 1 mV |
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: AM |
dB |
50 |
40 |
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SSB |
dB |
50 |
40 |
Squelch Sensitivity at Threshold |
: AM |
µV |
0.5 |
1 |
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SSB |
/IV |
0.25 |
0.5 |
S Meter Sensitivity at "S-9" (No Modulation AM) : AM |
AV |
100 |
25 — 400 |
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SSB |
pV |
100 |
25 — 400 |
Image Rejection Ratio. fo+(2x7.8 MHz) |
: AM |
dB |
80 |
70 |
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SSB |
dB |
80 |
70 |
1/2 IF Rejection Ratio. fo+7.8 MHz/2 |
: AM |
dB |
90 |
80 |
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SSB |
dB |
90 |
80 |
IF Rejection Ratio. 7.8 MHz |
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: AM |
dB |
85 |
75 |
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SSB |
dB |
85 |
75 |
Oscillator Dropout Voltage |
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: AM |
V |
9 |
11 |
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SSB |
V |
9 |
11 |
Clarifier Range |
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: AM |
kHz |
±1.25 |
±0.6 — ±2.5 |
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SSB |
kHz |
±1.25 |
±0.6 — ±2.5 |
Spurious Rejection Ratio |
In band |
: AM |
dB |
65 |
56 |
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SSB |
dB |
65 |
56 |
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Out of Band |
: AM |
dB |
60 |
50 |
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SSB |
dB |
60 |
50 |
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UNITS |
NOMINAL |
LIMIT |
Battery Drain at No Signal |
: AM |
mA |
550 |
1000 |
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SSB |
mA |
550 |
1000 |
Battery Drain at Maximum Output Power |
: AM |
mA |
1500 |
2000 |
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SSB |
mA |
1500 |
2000 |
PUBLIC ADDRESS:
Microphone Sensitivity for |
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3W Output Power at 1 kHz |
mV |
1 |
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Maximum Output Power |
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4 |
3 |
TRANSMITTER:
Frequency Tolerance at 25°C (5 Minutes |
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after switch on) |
: AM |
% |
±0.0005 |
±0.003 |
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SSB |
% |
±0.0005 |
±0.003 |
Carrier Power at No Modulation |
: AM |
W |
3.8 |
4.0 |
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PEP Power, Two Tone |
: SSB |
W PEP |
12 |
12.0 |
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Modulation Distortion at 1 kHz, 80% Modulation : AM |
% |
3 |
10 |
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Spurious Harmonic Emission |
: AM |
dB |
-65 |
-60 |
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SSB |
dB |
-65 |
-60 |
Carrier Suppression |
: SSB |
dB |
-55 |
-40 |
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Unwanted Sideband Suppression at 25 kHz |
: SSB |
dB |
-55 |
-40 |
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Modulation Frequency Response |
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(1 kHz, 0 dB reference) |
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Lower at 450 Hz, EIA |
: AM |
dB |
-6 |
-10 |
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SSB |
dB |
-6 |
-14 |
Upper at 2.5 kHz, EIA |
: AM |
dB |
-6 |
-10 |
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SSB |
dB |
-6 |
-10 |
Carrier Power Uniformity, |
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Ch to Ch at No Modulation |
: AM |
W |
0.3 |
0.4 |
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Mic Input Level Uniformity, Ch to Ch for 4 watts |
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Output .25 kHz Single tone - SSB |
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dB |
2 |
3 |
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Mic Input Level Uniformity, LSB to USB for |
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4 watts Output, 1.5 kHz Single Tone |
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dB |
1 |
3 |
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Microphone Sensitivity |
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AM: |
For 50% Modulation |
: AM |
mV |
1.0 |
2.0 |
SSB: For 4 watts PEP |
: SSB |
mV |
1.0 |
2.0 |
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AMC Range |
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AM: |
50 — 100% Modulation |
: AM |
dB |
46 |
40 |
SSB: 10 — 13.2 watts PEP |
SSB |
dB |
46 |
40 |
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Battery Drain at No Modulation |
: AM |
mA |
2200 |
2600 |
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SSB |
mA |
1000 |
1500 |
Battery Drain |
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AM: |
80% Modulation |
: AM |
mA |
2600 |
3000 |
SSB: 10 watts PEP, Two tone |
SSB |
mA |
2000 |
2700 |
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Note; |
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Nominal Specs represent the design specs; all units should be able to approximate these, some will exceed and some may drop slightly below these specs.
Limit Specs represent the absolute worst condition which still might be considered acceptable, in no case should a unit perform to less than within any Limit Spec.
2.DISASSEMBLY INSTRUCTIONS
1.To remove Top & Bottom Cover: (Figure 1)
Remove 4 screws from each side and a screw from top. Slide the top toward the rear of the chassis and remove.
2.To remove Front Panel: (Figure 2)
Remove 2 screws from each side.
Figure 1 |
Figure 2 |
Figure 3 |
Figure 4 |
3. BLOCK DIAGRAM
4. ALIGNMENT INSTRUCTIONS
CHASSIS LAYOUT-ALIGNMENT POINTS
VRI5 |
VRI6 |
/ VR12
Of.=>
VRI
VR3 VR2
L37
L8
CT I
0
VR5
L39 L7
L24
LI7
O
L16
T 4
TP2 I
CT7 |
VR8L 3 |
L I |
O
L4
L2
L5
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TP7 I |
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TP6 |
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VR 9 |
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CT6 |
0- |
TP91 |
0 |
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VR6 |
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CT5 |
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CD |
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VR7 |
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CT4 |
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0 |
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TP8 |
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CT2 |
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00 |
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CT3 |
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ALIGNMENT OF PLL AND CARRIER OSCILLATOR
1.Test equipment required:
a.Oscilloscope (DC — 50 MHz)
b.Frequency counter (0 — 30 MHz)
c.DC Power Supply (13.8V 100 mA)
d.DC Voltmeter (10V Maximum 100Kohm/V)
e.50 ohm Load
2.Alignment procedure: (See page 8) Connect Test Equipment as shown below.
STEP |
PRESET TO |
CONNECTIONS |
ADJUSTMENT |
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1 |
RX, AM, CH19 |
TP6 |
L24 |
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Clarifier: in center position |
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2 |
RX, AM, CH 1 |
TP7 |
L17 |
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Clarifier: in center position |
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3 |
Same as Step 1 |
TP8 |
L16 |
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4 |
Same as Step 1 |
TP8 |
CT6 |
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5 |
RX, USB, CH19 |
TP8 |
C1-4 |
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Clarifier, in center position |
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6 |
RX, LSB, CH19 |
TP8 |
CT5 |
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Clarifier: in center position |
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7 |
TX, LSB, CH19 |
TP8 |
VR9 |
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8 |
Same as Step 7 |
TP9 |
CT3 |
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9 |
TX, USB, CH19 |
TP9 |
CT2 |
REMARKS
Adjust for max. output.
Adjust for 2 V reading on Voltmeter.
Adjust for max. output.
Adjust to obtain 34.985 MHz ±20 Hz on frequency Counter.
Adjust to obtain 34.9875 MHz ±20 Hz on frequency Counter.
Adjust to obtain 34.9825 MHz ±20 Hz on frequency Counter.
Adjust to obtain 34.9825 MHz ±20 Hz on frequency Counter.
Adjust to obtain 7.7975 MHz ±5 Hz on frequency Counter.
Adjust to obtain 7.8025 MHz ±5 Hz on frequency Counter.
PLL AND CARRIER OSCILLATOR TEST EQUIPMENT SETUP
P.T.T.
TRC-449 Transceiver 5O5 Load
Mic. |
Ant. |
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0 Jack |
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:s Cse,
_Km/. _1
Probe
Frequency Counter
-41
0 Oscilloscope
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