Setting the Range Control

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 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. You should leave the range control in autorange for general use to ensure the accuracy of the measurement results.

If you prefer to use a fixed noise floor, you can disable autoranging in two ways using the [Setup], [Range Ctrl] function within Spectrum Analyzer:

On [Range Ctrl] select Hold to fix the front-end amplifier gain at the current level. You may use [Range Up] or [Range Down] to change the noise floor. A word of caution: when you use the Hold setting, a subsequent strong signal-even outside the measurement range-may cause an inaccurate reading due to overloading the front-end of the test set. While in Hold, you can adjust the gain of the front-end amplifier with the Range Up and Range Down menu keys. The Hold setting cannot be saved. Leaving the measurement or going into the sleep mode will reset the Range Ctrl to Auto.
On [Range Ctrl] select Max to fix the front-end amplifier gain at the current level until a strong signal comes in. When a strong signal is received, the front-end amplifier gain will be reduced to maintain accuracy, but it will not return to its lower level after the strong signal stops.

If the noise floor is too high to measure the signal of interest, reducing the resolution bandwidth will reduce the noise floor, at the expense of the measurement update rate.
Using the Range Control Function:

Step
Notes

1
Set the Range Ctrl to Hold.

[Setup]
[Range Ctrl]
On [Range Ctrl] select [Hold]
Select [Range Up] or [Range Down]

Each time you press this softkey, the selected option changes.
Use the Range Up or Range Down menu keys to adjust the gain to ensure the accuracy of the measurement results.

2
Set the Range Ctrl to Max.

[Setup]
[Range Ctrl]
On [Range Ctrl] select [Max]
For more information on the autoranging feature, refer to the note above.


	Step	Notes
1	Set the Range Ctrl to Hold. [Setup] [Range Ctrl] On [Range Ctrl] select [Hold] Select [Range Up] or [Range Down]	Each time you press this softkey, the selected option changes. Use the Range Up or Range Down menu keys to adjust the gain to ensure the accuracy of the measurement results.
2	Set the Range Ctrl to Max. [Setup] [Range Ctrl] On [Range Ctrl] select [Max]	For more information on the autoranging feature, refer to the note above.