Keysight N9038A, Руководство по обслуживанию

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296 Keysight N9038A MXE Service Guide
Front End Control
A15 Front End Control Assembly Troubleshooting
19. Measure the Bias voltage Test Points listed in Table 8-12 (Bias + and
Bias - values will only be correct when tuned above 13.6 GHz).
20. If any of the Bias voltages are incorrect the most likely cause of the
problem is the A15 Front End Control assembly.
21. If no trouble has been found with the A13 RF Front End assembly controls
coming from the A15 Front End Control assembly, yet there is still a
problem with the A13 RF Front End assembly, refer to Chapter 6, “RF
Downconverter Section.” for further troubleshooting information on the
A13 RF Front End assembly itself.
Table 8-12 A13 RF Front End Assembly Bias Voltages
Test Point Descriptions Voltage Tolerance
VCC1 LO Amp Bias +5.0V ± 0.5V
VCC2 LO Amp Bias +5.0V ± 0.5V
VCC3 Low Band Preamp Bias +8.0V ± 0.5V
VCC4 LO Amp Bias +5.0V ± 0.5V
VCC5 Output IF Amp Bias +5.0V ± 0.5V
VCC6 Aux LO Amp Bias + Future Use N/A
VEE6 Aux LO Amp Bias − Future Use N/A
VLO1 LO Power Level Control +3.0 to +5.0V ± 0.5V
VLO2 LO Power Level Control +3.0 to +5.0V ± 0.5V
TWAD1 LO Amp Bias +6.0V ± 0.5V
TWAD2 LO Amp Bias +6.0V ± 0.5V
TWAD3 High Band Input Amp Bias +6.0V ± 0.5V
TWAD4 LO Amp Bias +6.0V ± 0.5V
TWAD5 LO Amp Bias +6.0V ± 0.5V
IFAD1 Low Band IF Amp Bias +4.6V ± 0.5V
Bias + High Band Mixer Bias + (>13.6 GHz) Bias
+12.5V
a
± 1.5V
Bias − High Band Mixer Bias − (>13.6 GHz) Bias
−
12.5V
a ± 1.5V
a. Voltages will only be correct when the instrument is tuned above 13.6 GHz