110
Chapter 3
Manual Adjustment Procedures
1
. IF Bandpass Adjustment
1
. IF Bandpass Adjustment
Assembly Adjusted
A5 IF assembly
Related Performance Test
Resolution Bandwidth Accuracy and Selectivity
Description
The center frequency of each IF bandpass filter pole is adjusted by
DAC-controlled varactor diodes and an inductor (for the LC poles) or a
transformer (for the crystal poles). The inductors and transformers are
for coarse tuning and the varactors are for fine tuning by the
microprocessor. The inductors and transformers are adjusted such that
the varactor diodes are biased near the middle of their capacitance
range. The varactor diode bias is measured with the DVM.
NOTE
This procedure is not a routine adjustment. It should be performed only
if repairs to the A5 IF assembly are made. If the entire A5 IF assembly
is replaced, the assembly arrives pre-adjusted from the factory and
requires no further adjustment.
Figure 3-5
IF Bandpass Adjustment Setup
Summary of Contents for 8564EC
Page 17: ...25 1 General Information ...
Page 37: ...47 2 Adjustment Diagnostic Software ...
Page 77: ...89 3 Manual Adjustment Procedures ...
Page 129: ...161 3a Manual Adjustment Procedures 3335A Source not Available ...
Page 142: ...175 4 Assembly Replacement ...
Page 194: ...Chapter 4 257 Assembly Replacement Procedure 13 A21 OCXO Figure 4 34 A21 OCXO Mounting Screws ...
Page 196: ...259 5 Replaceable Parts ...
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Page 224: ...303 6 Major Assembly and Cable Locations ...
Page 234: ...315 7 General Troubleshooting ...
Page 238: ...Chapter 7 319 General Troubleshooting Introduction Figure 7 2 Ribbon Cable Connections 1 of 3 ...
Page 239: ...320 Chapter7 General Troubleshooting Introduction Figure 7 3 Ribbon Cable Connections 2 of 3 ...
Page 242: ...Chapter 7 323 General Troubleshooting Introduction Figure 7 5 Service Cal Data Menu ...
Page 271: ...352 Chapter7 General Troubleshooting Block Diagram Description Figure 7 6 Functional Sections ...
Page 283: ...364 Chapter7 General Troubleshooting Block Diagram Description ...
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Page 287: ...377 8 ADC Interface Section ...
Page 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
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Page 322: ...427 9 IF Section ...
Page 356: ...Chapter 9 461 IF Section A5 IF Assembly Figure 9 13 Detailed IF Adjust Signature 5 ...
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Page 379: ...487 10 Controller Section ...
Page 394: ...521 11 Synthesizer Section ...
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Page 454: ...593 12 RF Section ...
Page 489: ...628 Chapter12 RF Section A15 RF Assembly Figure 12 10 10 MHz TTL Reference at U304 Pin 13 ...
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Page 492: ...633 13 Display Power Supply Section ...
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Page 505: ...671 14 Component Level Information Packets ...
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