Technical data

Chapter 9 9-11
Accessories Troubleshooting
Test Set Troubleshooting
Measurement Control Signals
Voltage levels on the pins identified in Table 9-3 control measurement direction (forward or
reverse) and the doubler off function. Press and enter the
measurements listed below. After each entry, check the pins (see Figure 9-4) for the
indicated voltages.
• Proper Voltages: refer to the test set manual to continue troubleshooting. For 85047A
systems, first make sure that the appropriate test set has been “POKEd.”
• Wrong voltages: replace the A16 rear panel assembly of the analyzer.
Remote Trigger
Monitor pin 24 with an oscilloscope. Press : +5 should be present during preset.
After preset, a negative-going pulse to zero volts, about 200 nanoseconds long, should be
visible. The pulse should be present at the beginning of each sweep. To increase pulse
visibility, decrease the number of points to 3 and decrease the sweep time to
50 milliseconds on the analyzer.
• Proper pulse: refer to the test set manual to continue troubleshooting. For 85047A
systems, first make sure that the appropriate test set has been “POKEd.”
• Incorrect pulse: replace the analyzer A16 rear panel assembly.
Sweep Delay
This signal delays the start of the analyzer’s sweep to allow for test set switch settling
time. It also distinguishes, by encoding, the 85047A from the 85046A/B test sets. See the
test set manual for more detail. For 85047A systems, first make sure that the appropriate
test set has been “POKEd.”
Table 9-3 Measurement Voltage Matrix
HP/Agilent
85046A/B
HP/Agilent 85047A
Pin 8 Pin 8 Pin 22 Pin 23
Refl: FWD S11 (A/R)
+5 0 — +5
Trans: FWD S21 (B/R)
+5 0 — +5
Trans: REV S12 (B/R)
00—0
Refl: REV S22 (A/R)
00—0
Doubler OFF
—0+5—
Meas
S PARAMETERS
Preset