Agilent Technologies E4406A manual remains constant

Using System Features

Using System Configuration and Alignment Keys

Align Subsystem - Allows you to activate one or a group of the standard internal instrument alignments. Perform alignments on circuitry relating to the following internal alignments. Press the ESC key to cause any alignment to stop.

	Align RF - Activates an alignment on the RF circuitry.
	Align IF - Activates an alignment on the IF circuitry. The main
	gain of the Analog IF is used to compensate for prefilter BW gain
	variations so the gain of the entire IF path before the A/D
	remains constant.
	Align ADC - Activates an alignment on the ADC circuitry.
	Align 50 MHz Reference - Enables a service technician to
	adjust the amplitude of the internal 50 MHz reference signal for
	absolute amplitude accuracy. The test equipment and the
	adjustment procedure required are described in the E4406A
	service guide.
	The Align 50 MHz reference feature can only be activated if you have a
NOTE
	service password. The password is not available unless the user has
	purchased the service guide.
	Align Current IF Flatness - Activates an immediate
	measurement of the current IF flatness, for FFT spectral
	amplitude compensation. Normally this alignment occurs in the
	background when the instrument bandwidth is changed. Given
	the current BW and Gain DAC settings for a measurement,
	alignment is done using the comb calibration signal. The relative
	amplitude of combs within the BW are compared to expected
	amplitudes to generate the effective shape of the current IF path.
	If Time Corrections are active, this alignment generates complex
	IF responses (magnitude and phase) rather than just the original
	scalar (magnitude) response. The complex alignment requires
	reasonable delay estimation, and improved trigger compensation
	so the phase response of several averaged measurements can be
	unwrapped properly.
	Align Current SysGain - Activates a fine-tuning adjustment of
	the system gain. This is done by measuring the response of the
	current system state configuration to the 50 MHz amplitude
	reference signal. All subsequent measurements are then
	compensated appropriately for absolute amplitude accuracy.
	Normally this occurs in the background when the instrument
	bandwidth is changed.

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