Setting the Range Control

---

The autoranging feature, which is built into the test set, helps ensure accurate measurements by changing front-end amplifier gain as needed, for example, when a strong signal threatens to overload the test set. When this occurs, the noise floor rises (as gain is decreased), then falls again when the strong signal stops. To select this feature:

• On [Range Ctrl] select Auto to enable the E7495A/B to continuously adjust the noise floor to the optimum setting.

If you prefer a fixed noise floor, you can disable autoranging in two ways using the Setup function within Spectrum Analyzer:

• On [Range Ctrl] select Hold to fix the noise floor at the current level. A subsequent strong signal-even outside the measurement range-may cause an inaccurate reading due to overloading the front-end of the test set.
• On [Range Ctrl] select Max to fix the noise floor at the current level until a strong signal comes in. In that case, the floor will rise to maintain accuracy, but will not return to its lower level after the strong signal stops.

  	Step	Notes
  1.	[Setup]
  2.	[Range Ctrl]
  3.	[Auto] [Hold] or [Max]