Theory Of Operation - Keysight 85024A User's And Service Manual

7 Service

Theory of Operation

The probe uses a Gallium Arsenide FET integrated circuit amplifier which provides
unity gain. This amplifier microcircuit requires +6 V and –4 Vdc to operate. These
voltages are provided by the regulator assembly.
The regulator assembly converts the +15 volt and –12.6 volt supplies from the
host instrument with two voltage regulators. The regulator supplies the +6 and –4
voltages to the amplifier microcircuit.
The most common failures in the probe will all result in loss of signal through the
probe, and will show up if the operator's check is performed. The most common
failures are expected to be:
1 Destruction of the amplifier microcircuit due to static electricity (proper
2 Probe power tip damage (caused by the operator dropping the probe with the
3 Possible regulator failure.
58
anti-static precautions not taken).
sleeve retracted).
Keysight 85024A User's and Service Guide