
8. 21.4 MHz Bandwidth Filter Adjustments
8. 21.4 MHz
Bandwidth Filter
Adjustments
Reference
Related Performance
Tests
Description
IF-Display Section
Bandwidth Filter
Attenuator-Bandwidth Filter
IF Gain Uncertainty Test
Resolution Bandwidth Switching Uncertainty test
Resolution Bandwidth Selectivity Test
First the LC Filters (100
to 3 MHz bandwidths) on the
Bandwidth Filter are adjusted. The crystal filter poles (3
to 30
bandwidths) are then adjusted for center and symmetry by
bypassing all but one pole at a time and adjusting the active pole.
Next, the LC filters and the crystal filter poles on the
Attenuator-Bandwidth Filter are adjusted in the same manner as on
the
Bandwidth Filter.
Last, the 10
and 20
attenuators on the
Bandwidth Filter are adjusted for the proper amount of attenuation.
This is done by connecting the CAL OUTPUT signal to the RF INPUT
through two step attenuators, keying in the necessary reference level
to activate the 10
and the 20
control lines, adjusting the step
attenuators to compensate for the attenuation, and adjusting the
attenuators for the proper amount of attenuation.
SPECTRUM ANALYZER
I
DIGITAL VOLTMETER
STEP
STEP
ATTENUATOR
ATTENUATOR
Figure 3-40. 21.4 MHz Bandwidth Filter Adjustments Setup
Adjustments 3-77
Summary of Contents for 8568B
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