Dynamic Attenuation Control - Anritsu spectrum master ms2711d User Manual

Chapter 5 Field Measurements

Dynamic Attenuation Control

The dynamic attenuation control feature tracks the peak input signal level and automatically
adjusts the attenuator to protect the MS2711D in situations of high RF signal levels. This
feature also enhances the instrument sensitivity in situations of low-level RF signals by de-
activating and activating the internal preamplifier resulting in improved measurement accu-
racy.
When dynamic attenuation is on, the MS2711D is in control of the attenuation and preamp.
Manual settings will be overwritten based on the input signal. To manually control these
parameters, set the attenuation to Manual.
The following is an example identifying interference in a PCS 900 MHz band with the aid
of the preamplifier and dynamic attenuation control.
Required Equipment
MS2711D Handheld Spectrum Master
l
A PCS band Pass Filter, such as K & L Electronics 5DR30-921 or equivalent
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A PCS band antenna
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Procedure
Step 1. If necessary, press the MODE key and use the Up/Down arrow key to select the
Spectrum Analyzer mode. Press the ENTER key to select.
Step 2. Reset the MS2711D to the factory default settings for the current mode by press-
ing the RECALL SETUP key on the data keypad. When the key is pressed, a
Recall Setup selection box appears on the display. Select setup location 0 <De-
fault> to recall the factory preset state for the currently selected mode.
Step 3. Connect the PCS antenna to the input of the band pass filter, and the output of
the band pass filter to the RF In connector of the MS2711D.
Step 4. Press the FREQ/SPAN key.
Step 5. Press the Start soft key and enter 1.93 MHz.
Step 6. Press the Stop soft key and enter 1.935 MHz.
Step 7. Press the AMPLITUDE key and select the Scale key. Set the scale to 10 dB/di-
vision.
Step 8. Press the Atten/Preamp soft key and set the attenuation to Dynamic.
As the MS2711D sweeps, it continually monitors the overall input signal level and, as re-
quired, adjusts the input attenuation value and the preamplifier on/off state to achieve the
best possible sensitivity.
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