HP 8560E Service Manual page 507

Synthesizer Section
Introduction
Introduction
The synthesizer section includes the A7 first LO distribution amplifier,
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.
Synthesizer Troubleshooting Section.................................
Test Setup Troubleshooting................................................
Troubleshooting Using the TAM ........................................
General PLL Troubleshooting ............................................
PLL Locked at Wrong Frequency.....................................
Unlocked PLL....................................................................
Unlocked Reference PLL (100 MHz VCXO) ......................
Operation (100 MHz VCXO).............................................
Troubleshooting (100 MHz VCXO)...................................
Third LO Driver Amplifier (100 MHz VCXO) .................
Unlocked Reference PLL (600 MHz SAWR) ......................
Operation (600 MHz SAWR).............................................
Troubleshooting (600 MHz SAWR) ..................................
Third LO Driver Amplifier (600 MHz SAWR) .................
Unlocked Offset Lock Loop (Sampling Oscillator) ............
Operation...........................................................................
Troubleshooting.................................................................
Unlocked YTO PLL .............................................................
Operation...........................................................................
Troubleshooting an Unlocked YTO PLL..........................
Unlocked Fractional N PLL................................................
Operation...........................................................................
Confirming an Unlocked Condition..................................
Fractional N PLL ..............................................................
Frequency Span Accuracy Problems ..................................
Determining the First LO Span .......................................
Confirming Span Problems...............................................
YTO Main Coil Span Problems (LO Spans >20 MHz) ......
YTO FM Coil Span Problems (LO Spans 2.01 MHz to 20 MHz)
Fractional N Span Problems (LO Spans ≤2 MHz) ..........
First LO Span Problems (All Spans)................................
Phase Noise Problems.........................................................
Phase Noise in Locked versus Lock-and-Roll Spans .......
Reference versus Reference PLL Phase Noise ................
Fractional N versus Offset PLL or YTO PLL Phase Noise
Fractional N PLL Phase Noise .........................................
Sampler and Sampler IF ....................................................
Sweep Generator Circuit ....................................................
A21 OCXO ...........................................................................
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Chapter 10