392
Chapter 8
ADC/Interface Section
A3 Assembly Video Circuits
13.Press
CAL
and
IF ADJ ON OFF
until OFF is underlined. Monitor
A3TP9 with an oscilloscope. If the voltage is not approximately
+1 Vdc, troubleshoot the Log Amplifier on A4. (Refer to the IF
troubleshooting procedure in
14.To confirm proper video input to the video circuit, set the spectrum
analyzer to Log 10 dB per division and change the reference level in
10 dB steps from
−
10 dBm to +30 dBm. At each 10 dB step, the input
voltage should change 100 mV. The input level should be +0.6 Vdc
for a +30 dBm reference level.
NOTE
The on-screen amplitude level will probably not change as expected,
since the video circuitry is assumed to be faulty.
15.Monitor A3TP14 while stepping the reference level from
−
10 dBm to
+30 dBm. If the voltage does not step approximately 100 mV per
10 dB step, refer to
16.If the Video MUX is working properly, monitor A3TP15 with the
oscilloscope and step the reference level from
−
10 dBm to +30 dBm.
If the voltage does not change 100 mV per 10 dB step, refer to
17.If the voltage at A3TP15 is correct, move the oscilloscope probe to
A3TP17 and step the reference level between
−
10 dBm and
+30 dBm. If the voltage does not change 100 mV per 10 dB step,
refer to
“Video Filter Buffer Amplifier” on page 396
18.If the voltage at A3TP17 is correct, move the oscilloscope probe to
A3TP6. Set the following controls to keep the ADC MUX set to the
MOD_VIDEO input during the sweep:
Sweep time .................................................................... 50 s
Detector mode .......................................................... Sample
19.Step the reference level from
−
10 dBm to +30 dBm while monitoring
the voltage change on the oscilloscope. If the voltage does not change
100 mV per 10 dB step, refer to
20.If the voltage at A3TP6 is correct, move the oscilloscope probe to
A3TP8 and step the reference level between
−
10 dBm and +30 dBm.
If the voltage at A3TP8 is not the same as that at A3TP6, replace
A3U110.
21.If the voltage at A3TP8 and A3TP6 are equal, move the oscilloscope
probe to A3TP7.
22.Change the reference level from
−
10 dBm to 0 dBm. The voltage
change on A3TP7 should be between 630 mV and 770 mV. If the
voltage change is outside of these limits, refer to
7
±
10%.
Содержание 8564EC
Страница 17: ...25 1 General Information ...
Страница 37: ...47 2 Adjustment Diagnostic Software ...
Страница 55: ...Chapter 2 65 Adjustment Diagnostic Software 2 LO Frequency Figure 2 2 LO Frequency Adjustment Locations ...
Страница 57: ...Chapter 2 67 Adjustment Diagnostic Software 3 YTO FM Coil Figure 2 3 YTO FM Coil Adjustment Locations ...
Страница 77: ...89 3 Manual Adjustment Procedures ...
Страница 129: ...161 3a Manual Adjustment Procedures 3335A Source not Available ...
Страница 142: ...175 4 Assembly Replacement ...
Страница 151: ...184 Chapter4 Assembly Replacement Procedure 2 A1 Front Frame A18 LCD Figure 4 2 LCD Assembly Exploded View ...
Страница 163: ...Chapter 4 205 Assembly Replacement Procedure 5 A2 A3 A4 and A5 Assemblies Figure 4 10 Assembly Cables 2 of 3 ...
Страница 166: ...208 Chapter4 Assembly Replacement Procedure 5 A2 A3 A4 and A5 Assemblies Figure 4 14 GPIB and A1A1 W1 Cable Placement ...
Страница 168: ...210 Chapter4 Assembly Replacement Procedure 6 A6 Power Supply Assembly Figure 4 15 Power Supply Cover ...
Страница 176: ...226 Chapter4 Assembly Replacement A9 Input Attenuator Figure 4 22 A9 and A10 A12 Mounting Screws ...
Страница 179: ...Chapter 4 229 Assembly Replacement A11 YTO Figure 4 23 A11 Mounting Screws at Right Side Frame ...
Страница 183: ...Chapter 4 233 Assembly Replacement Procedure 8 A14 and A15 Assemblies Figure 4 25 A14 and A15 Assembly Cables ...
Страница 190: ...Chapter 4 243 Assembly Replacement Procedure 11 Rear Frame Rear Dress Panel Figure 4 29 A6 Power Supply Cover ...
Страница 194: ...Chapter 4 257 Assembly Replacement Procedure 13 A21 OCXO Figure 4 34 A21 OCXO Mounting Screws ...
Страница 196: ...259 5 Replaceable Parts ...
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Страница 224: ...303 6 Major Assembly and Cable Locations ...
Страница 228: ...Chapter 6 307 Major Assembly and Cable Locations Introduction Figure 6 2 Top View A2 and A3 Unfolded ...
Страница 229: ...308 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 3 Top View A2 A3 A4 and A5 Unfolded ...
Страница 230: ...310 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 5 Bottom View A15 Unfolded ...
Страница 231: ...Chapter 6 311 Major Assembly and Cable Locations Introduction Figure 6 6 Bottom View A15 and A14 Unfolded ...
Страница 233: ...314 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 9 Rear View FL4 B1 BT1 A20 VGA Connector ...
Страница 234: ...315 7 General Troubleshooting ...
Страница 238: ...Chapter 7 319 General Troubleshooting Introduction Figure 7 2 Ribbon Cable Connections 1 of 3 ...
Страница 239: ...320 Chapter7 General Troubleshooting Introduction Figure 7 3 Ribbon Cable Connections 2 of 3 ...
Страница 242: ...Chapter 7 323 General Troubleshooting Introduction Figure 7 5 Service Cal Data Menu ...
Страница 271: ...352 Chapter7 General Troubleshooting Block Diagram Description Figure 7 6 Functional Sections ...
Страница 283: ...364 Chapter7 General Troubleshooting Block Diagram Description ...
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Страница 287: ...377 8 ADC Interface Section ...
Страница 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
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Страница 322: ...427 9 IF Section ...
Страница 356: ...Chapter 9 461 IF Section A5 IF Assembly Figure 9 13 Detailed IF Adjust Signature 5 ...
Страница 358: ...Chapter 9 463 IF Section A5 IF Assembly Figure 9 14 Noisy Signature Figure 9 15 Noise with Correct Shape ...
Страница 359: ...464 Chapter9 IF Section A5 IF Assembly Figure 9 16 Region B Amplitude Variation Figure 9 17 Region B Amplitude Offset ...
Страница 369: ...474 Chapter9 IF Section Cal Oscillator P O A4 Assembly Figure 9 21 Output Waveform 10 kHz Resolution Bandwidth ...
Страница 370: ...Chapter 9 475 IF Section Cal Oscillator P O A4 Assembly Figure 9 22 Output Waveform 3 kHz Resolution Bandwidth ...
Страница 371: ...476 Chapter9 IF Section Cal Oscillator P O A4 Assembly Figure 9 23 Output Waveform 1 kHz Resolution Bandwidth ...
Страница 372: ...Chapter 9 477 IF Section Cal Oscillator P O A4 Assembly Figure 9 24 Output Waveform 300 Hz Resolution Bandwidth ...
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Страница 379: ...487 10 Controller Section ...
Страница 394: ...521 11 Synthesizer Section ...
Страница 431: ...564 Chapter11 Synthesizer Section Unlocked Fractional N PLL Figure 11 8 VCO Bias Voltages for A14 Assemblies ...
Страница 447: ...Chapter 11 581 Synthesizer Section Sweep Generator Circuit Figure 11 11 Simplified Synthesizer Section ...
Страница 448: ...582 Chapter11 Synthesizer Section Sweep Generator Circuit Figure 11 12 Simplified A14 Assembly Block Diagram ...
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Страница 454: ...593 12 RF Section ...
Страница 475: ...614 Chapter12 RF Section A14 Frequency Control Assembly Figure 12 4 A7 LO Multiplier Amplifier Drive ...
Страница 489: ...628 Chapter12 RF Section A15 RF Assembly Figure 12 10 10 MHz TTL Reference at U304 Pin 13 ...
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Страница 492: ...633 13 Display Power Supply Section ...
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Страница 505: ...671 14 Component Level Information Packets ...
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