Keysight N9038A MXE Service Guide 287
Front End Control
A15 Front End Control Assembly Troubleshooting
10.Verify that the voltage levels of test points In1A, In1B, In2A, and In2B
match what is outlined in Table 8-7 for a Frequency of 1 GHz (±0.5V).
If the test point voltages are correct proceed to the next step. If not, there
is most likely a problem with the A15 Front End Control assembly.
11.Tune the instrument to a frequency of 4 GHz by pressing FREQ, 4 GHz.
12.Verify that the voltage levels of test points In1A, In1B, In2A, and In2B
match what is outlined in Table 8-7 for a Frequency of 4 GHz (±0.5V).
If the test point voltages are correct proceed to the next step. If not, there
is most likely a problem with the A15 Front End Control assembly.
13.Turn off the RF Preselector by pressing Input/Output, RF Input, RF
Preselector, Off.
14.Turn the High Band Preamp on by pressing AMPTD, More, Internal
Preamp, Full Range.
15.Verify that the voltage levels of test points In1A, In1B, In2A, and In2B
match what is outlined in Table 8-7 for a Frequency of 4 GHz w/ Preamp
(±0.5V).
If the test point voltages are correct proceed to the next step. If not, there
is most likely a problem with the A15 Front End Control assembly.
16.If no trouble has been found with the control logic coming from the A15
Front End Control assembly, yet there is still a problem with the A11 RF
Switch / High Band Preamp assembly, refer to Chapter 6, “RF
Downconverter Section.” for further troubleshooting information on the
A11 RF Switch / High Band Preamp assembly itself.
Table 8-7 A11 RF Switch / High Band Preamp Control Voltage
Frequency In1A In2A In1B In2B
1 GHz −10V −10V +10V +10V
4 GHz +10V −10V −10V +10V
4 GHz w/ Preamp +10V +10V −10V −10V
To Next Page
Loading...
