Agilent Technologies 8753ES Option 011 Service Manual page 240

Source Troubleshooting
Phase Lock Error
A4 Sampler/Mixer Check
The A4, A5, and A6 (R, A and B) sampler/mixers are similar in operation. Any sampler can
be used to phase lock the source. To eliminate the possibility of a faulty R sampler, follow
this procedure.
1. Connect the power splitter, RF cable and attenuator to inputs A (or B) and R as shown
in Figure 7-1.
2. Remove the W8 cable (A11J1 to A4) from the R-channel sampler (A4) and connect it to
either the A-channel sampler (A5) or the B-channel sampler (A6), depending on which
one you selected in step 1. Refer to
Figure 7-3 Sampler/Mixer to Phase Lock Cable Connection Diagram
3. Remove the W8 cable (A11J1 to A4) from the R-channel sampler (A4) and connect it to
either the A-channel sampler (A5) or the B-channel sampler (A6). Refer to
4. If you connected W8 to:
• A5, press
Meas
• A6, press
Meas
5. Ignore the displayed trace, but check for phase lock error messages. If the phase lock
problem persists, the R-channel sampler is not the problem.
A3 Source and A11 Phase Lock Check
This procedure checks the source and part of the phase lock assembly. It opens the
phase-locked loop and exercises the source by varying the source output frequency with the
A11 pretune DAC.
7-8
Figure
A/R
B/R
7-3.
Figure 7-3.
Chapter 7