Agilent Technologies 8753ES Option 011 Service Manual page 316

Service Key Menus and Error Messages
Service Key Menus
Node 4 Det (detects RF OUT power level)
Perform step A3, described previously, to set up a power sweep on the analog bus. Then
press
ANALOG IN
Meas
Node 4 detects power that is coupled and detected from the RF OUT arm to the ALC loop.
Note that the voltage exponentially follows the power level inversely. Flat segments
indicate ALC saturation and should not occur between −85 dBm and +10 dBm.
Figure 10-6 Analog Bus Node 4
Node 5 Temp (temperature sensor)
This node registers the temperature of the cavity oscillator which must be known for
effective spur avoidance. The sensitivity is 10 mV/°C. The oscillator changes frequency
slightly as its temperature changes. This sensor indicates the temperature so that the
frequency can be predicted.
10-26
4 x1 Scale Ref
.
AUTO SCALE
Chapter 10