Checking Alc Operation < 3.2 Ghz (N5173B/83B) - Keysight N5171B EXG Service Manual

Troubleshooting
Checking ALC Operation < 3.2 GHz (N5173B/83B)
Checking ALC Operation < 3.2 GHz (N5173B/83B)
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
2. Set up the signal generator:
3. Using
4. Measure the center pin voltage on the J18 connector using an
Figure 1-20 ALC LOB MOD Connector and Cable
96
"Assembly Replacement."
covers.
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 > 0 > dBm.
Figure 1-20, remove the W23 modulator drive cable from ALC LOB
MOD (J18).
oscilloscope.
Table 10 on page 97
for instructions on removing the instrument
Keysight X-Series Signal Generators Service Guide
Chapter 3,