580
Chapter 11
Synthesizer Section
Sweep Generator Circuit
Press
PRESET
and set the spectrum analyzer to the following
settings:
18.Using an oscilloscope, check that the sweep ramp at A14U320 pin 6
sweeps linearly from 0 to +10 Volts in 50 ms, then resets to 0 Volts.
19.Change the sweep time to 10 seconds and check that the sweep ramp
(U320 pin 6) sweeps linearly from 0 to +10 Volts in 10 seconds, then
resets to 0 Volts.
20.Change the spectrum analyzer settings as follows:
Span ................................................................................. 0 Hz
Sweep time ................................................................... 10 ms
21.Check that the ramp (U320 pin 6) sweeps linearly from 0 to
+10 Volts in 10 ms, then resets to 0 Volts.
22.If the any of the sweep times were not within specification or the
sweep ramp appeared to be non-linear in the preceding steps,
proceed with the following checks:
23.Connect the negative lead of a voltmeter to A14Q3 pin 8 and connect
the positive lead to A14U312 pin 1 to check the temperature sensor
(U312).
24.The voltage at pin 1 should be 10 mV/
°
C times the temperature of
the A14 frequency control assembly. (For example, if the ambient
temperature is approximately 20
°
C, and the A14 frequency control
assembly is 10
°
C warmer, the actual temperature of the A14
assembly is 30
°
C and U312 pin 1 should measure 300 mV.)
25.To check the temperature-dependent offset voltage generator,
connect the positive lead of the voltmeter A14Q3 pin 6. The
voltmeter should read
−
600 mV
±
150 mV.
26.To check the DAC buffer, A14U334A, connect the positive lead of the
voltmeter to A14U334 pin 2. The voltmeter should read the same
voltage measured at A14Q3 pin 6, within 2 mV. (The same voltage
should be present at U334 pin 3.)
27.To check the buffered DAC, press
PRESET
and set the spectrum
analyzer as follows:
Center frequency .................................................. 300 MHz
Span ...................................................................... 100 MHz
Sweep time ................................................................. 50 ms
28.Connect the positive lead of the voltmeter to A14U334 pin 1. The
voltmeter should read the same voltage measured at U334 pin 2,
within 2 mV.
29.Change the spectrum analyzer sweep time to 2000 seconds. The
voltage at A14U334 pin 1 should increase by 275 mV
±
20 mV
(compared to the voltage measured in step 12).
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 ...
Page 218: ......
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Page 223: ......
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 ...
Page 284: ......
Page 285: ......
Page 286: ......
Page 287: ...377 8 ADC Interface Section ...
Page 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
Page 321: ......
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 453: ......
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 ...
Page 504: ......
Page 505: ...671 14 Component Level Information Packets ...
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