Agilent Technologies 8564EC Service Manual page 395

Synthesizer Section
Introduction
Introduction
The synthesizer section includes the A7 LOMA (LO multiplier/
amplifier), the A11 YTO, and parts of the A14 frequency control and
A15 RF assemblies. Simplified and detailed block diagrams for each
assembly are located at the end of this chapter.
Test Connector Locations..............................................
Troubleshooting Test
Confirming a Faulty Synthesizer Section
General PLL Troubleshooting
PLL Locked at Wrong Frequency
Unlocked PLL .............................................................page 535
Unlocked Reference PLL (100 MHz VCXO)
Operation (100 MHz VCXO)
Troubleshooting (100 MHz VCXO)
Third LO Driver Amplifier (100 MHz VCXO)
Unlocked Offset Lock Loop (Sampling Oscillator)
Operation ....................................................................page 547
Troubleshooting
Unlocked YTO PLL
Operation ....................................................................page 551
Troubleshooting an Unlocked YTO PLL
Unlocked Fractional N PLL
Operation ....................................................................page 560
Confirming an Unlocked Condition
Fractional N PLL
Frequency Span Accuracy Problems
Determining the 1st LO Span
Confirming Span Problems .......................................
YTO Main Coil Span Problems (LO Spans >20 MHz)
YTO FM Coil Span Problems (LO Spans 2.01to 20 MHz) .
Fractional N Span Problems (LO Spans ≤2 MHz)
1st LO Span Problems (All Spans)
1st LO Span Problems (Multiband Sweeps)
Phase Noise Problems
Phase Noise in Locked versus Unlocked Spans
Reference versus Reference PLL Phase Noise
Fractional N versus Offset PLL or YTO PLL Phase Noise
Sampler and Sampler IF
Sweep Generator Circuit
A21 OCXO .....................................................................page 585
522
Setup...........................................page 527
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Chapter 11