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November 24, 2003
HKLN4216A
5-16
VHF Troubleshooting Tables:
Troubleshooting Table for Board and IC Signals
Notes:
U480
Dual Opamp
1
Unit 1 output
2.48
2
Unit 1 (-) input
2.48
3
Unit 1 (+) input
2.46
4
Ground
GND
5
Unit 2 (+) input
0.28
6
Unit 2 (-) input
0.29
7
Unit 2 output
0
8
Vcc
4.96
U490
Audio Power Amp
1
Enable/shutdown
0.12
(Unsquelched)
2
Bias reference
3.26
(Unsquelched)
3
(+) input
3.26
(Unsquelched)
4
(-) input
3.27
(Unsquelched)
5
(-) output
3.25
(Unsquelched)
6
Vcc
7.48
(Unsquelched)
7
Ground
GND
8
(+) output
3.29
(Unsquelched)
U510
Dual Opamp
1
Unit 1 output
1.75
2
Unit 1 (-) input
1.56
3
Unit 1 (+) input
1.55
4
Ground
GND
5
Unit 2 (+) input
1.55
6
Unit 2 (-) input
1.56
7
Unit 2 output
1.38
8
Vcc
4.96
1. All voltages are measured with a high-impedance digital voltmeter and expressed in volts DC relative to ground (0 V).
2. Voltages are measured with a DC input voltage of 7.50 + .02 volts DC applied to the battery connector (J301).
3. All voltages are measured in the squelched receive mode, unless otherwise indicated.
4. Voltages are identical for VHF and UHF models unless otherwise indicated.
Table 5-4. Troubleshooting Table for Board and IC Signals (Continued)
IC Designator
Pin
Pin Function
DC Voltage
Comments (Condition)
Содержание EP450
Страница 31: ...November 24 2003 HKLN4216A 4 8 VHF Theory Of Operation Keypad Notes ...
Страница 77: ...November 24 2003 HKLN4216A Notes 7 8 403 440 MHz UHF Theory Of Operation Keypad ...
Страница 85: ...November 24 2003 HKLN4216A Notes 8 8 438 470 MHz UHF Theory Of Operation Keypad ...
Страница 93: ...November 24 2003 HKLN4216A Notes 9 8 465 495 MHz UHF Theory Of Operation Keypad ...
Страница 109: ...November 24 2003 HKLN4216A Notes 10 16 UHF Troubleshooting Tables Troubleshooting Table for Board and IC Signals ...
Страница 113: ...November 24 2003 HKLN4216A Notes 11 4 UHF Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic ...