Agilent N5161A/62A/81A/82A/83A MXG Signal Generators Service Guide
Troubleshooting
Checking ALC Operation < 3.2 GHz (N5183A)
1-48
6.
Using the spectrum analyzer, measure the lowest power level at the attenuator output.
•
If the lowest power level is less than the specified power shown in the maximum output power section of the
N5183A Data Sheet:
a.
Replace the A7 Micro Deck.
b.
Chapter 4, "Post-Repair Procedures and Performance Verification"
•
If the lowest power level is greater than the specified power level shown in the maximum output power section of the
N5183A Data
Sheet
:
a.
Reconnect the cable to the attenuator.
b.
Disconnect the cable from the RF output connector.
c.
Check the loss through the cable.
d.
If the cable loss is >1dB, replace the cable.
e.
If the cable is good, reconnect the cable to the RF output connector.
f.
Measure the loss through the RF output connector.
g.
If the RF connector loss is >2dB, replace the connector.
7.
If any of the parts are replaced, go to
Chapter 4, "Post-Repair Procedures and Performance Verification"
.
Checking ALC Operation < 3.2 GHz (N5183A)
In this procedure you are looking for a pattern in the voltage change when you change the amplitude. For each change in amplitude, you
should measure a change of approximately one volt, relative to the previous and subsequent voltage values. The Example Voltages column in
demonstrates this change while also showing that it is not always exactly one volt.
1.
Remove the external cover and the top inside cover. Refer to
Chapter 3, "Assembly Replacement"
for instructions on removing the
instrument covers.
2.
Set up the signal generator:
a.
Press
Preset
.
b.
Press
FREQ
>
2
>
GHz
.
c.
Press
RF On/Off
to On.
d.
Press
AMPTD
>
ALC Off On
to Off.
e.
Press
Atten/ALC Control > Atten Hold Off On
to On.
f.
Press
Set Atten
>
0
>
dB
.
g.
Press
AMPTD
>
10
>
dBm
.
3.
, remove the W14 modulator drive cable from ALC LOB MOD (J15).
4.
Measure the center pin voltage on the J15 connector using an oscilloscope.
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