HP 8560E Service Manual page 508

All of the assemblies are extremely sensitive to electrostatic discharge
CAUTION
(ESD). For further information regarding electrostatic cautions, refer to
"Electrostatic Discharge Information" in Chapter 1.
Using an active probe, such as an HP 85024A, with a spectrum
CAUTION
analyzer is recommended for troubleshooting the RF circuitry. If an HP
1120A active probe is being used with a spectrum analyzer, such as the
HP 8566A/B, or HP 8569A/B having dc coupled inputs, either set the
active probe for an ac coupled output or use a dc blocking capacitor (HP
11240B) between the active probe and the spectrum-analyzer input.
Some spectrum analyzers can be set to ac coupled. Failure to do this can
result in damage to the spectrum analyzer or the probe.
Chapter 10
Synthesizer Section
Introduction
507