Service manual

3-42 8510XF Network Analyzer Systems
Operation
IF Frequency
IF Frequency
The IF used by the network analyzer is nominally 20 MHz. However, it is
desirable to add a slight offset to that frequency; the offset provides
immunity against spurious 20 MHz signals, which can have a detectable
impact on measurement when averaging is used. In the 8510XF, the factory
preset default value of the IF is 20.000017 MHz (in other words, an offset of
17 Hz has been added).
The key sequence
[SYSTEM] {MORE} {IF FREQ}, followed by a frequency, can be
used to change the value of the IF frequency. The effective range of
modification is restricted by hardware performance characteristics (typically,
the IF range is 20 MHz
+10 kHz).
NOTE At measurement frequencies greater than 18 GHz, the actual IF may differ
slightly from the set value, owing to the frequency resolution of the RF and
LO sources.