HP 8901B Operation And Calibration Manual page 329

Model 8901B Operation
DETAILED DESCRIPTIONS OF ALL SPECIAL FUNCTIONS
1. RF Input Attenuation.
Use this special function
to
select
F W
input attenuation
to
eliminate input
overload or to improve measurement sensitivity. For more details about this function, refer to RF Input
Attenuation on page 3-231.
1.0 Automatic selection
1.1 Attenuation of 0
dB
1.2 Attenuation of 10
dB
1.3 Attenuation of 20
dB
1.4 Attenuation of 30
dB
1.5 Attenuation of
40
dB
1.6 Attenuation of 50
dB
2.
Audio Range Selection.
Use this special function to set the display resolution for modulation
measurements. The Modulation Analyzer's display resolution is dependent on the modulation being
measured and the detector being used. For example, in
FM
measurements, Special k c t i o n 2.4 can
only display 0.01 Hz resolution when the deviation being measured is less than 0.04 peak kHz and
when the RMS detector is selected. Because this special function is so complex, it is not described in
detail here. Refer to Audio Range on page 3-183, for detailed tables for this function.
3.
RF and IF Filters.
Use this special function to change the Modulation Analyzer's
RF
and IF
filters. (Refer
to
Filters, RF and IF on page 3-229 for information about the usefulness of changing
these filters.)
IN
2.5 MHz
Low- Pass
3.8 SPCL 3.8SP 455 kHz
5.
Audio Detector Response.
Use this special function to help stabilize measurements on unstable
or noisy signals when making modulation or
SINAD
measurements.'
5.0 Fast response time.
5.1 Slow response time.
The slow response time for SINAD is not available with firmware date codes
234.1985 and below. (To display the firmware
date code, select 42.0
SPCL.) To order a
ROM
set that contains this special function, contact the nearest HP sales office.
3-241