Chapter 11
553
Synthesizer Section
Unlocked YTO PLL
Troubleshooting an Unlocked YTO PLL
1. If the YTO PLL is unlocked, error code 301 should be displayed.
Place the spectrum analyzer in ZERO SPAN.
illustrates the simplified YTO PLL.
2. Move the jumper on A14J23 to connect pins 2 and 3 (TEST position).
Refer to
for the location of A14J23. Error
code 301 should no longer be displayed. (The YTO PLL feedback
path is now open and the YTO error voltage is forced to zero.)
3. On the spectrum analyzer, press
CAL
,
MORE 1 OF 2
,
FREQ DIAGNOSE
,
and
LO FREQ
. The displayed LO FREQ is the desired YTO frequency
calculated. Record the calculated YTO frequency below:
4. Measure the YTO frequency at the front-panel 1ST LO OUTPUT
jack and record below:
Table 11-5
Amplifier Polarities
YTO Error Sign
Amplifier
ERRSGN
(A14U313 pin 19)
Fractional N
Positive
Positive
TTL High
Oscillator
Swept
Sampler IF
Negative
Negative
TTL Low
Sampler IF
FM/Main
YTO
Positive
Positive
TTL High
Coils Swept
Sampler IF
Negative
Negative
TTL Low
Sampler IF
YTO frequency (calculated) =__________________ MHz
YTO frequency (measured) = ___________________MHz
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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