Chapter 5
Test and Measurement Functions
CX300 Meters
Rev. 001
CX300 ComXpert Operation Manual
22130634
5 - 34
February, 2022
Psophometric
Filter
Psophometric filters are typically used when measuring the
residual noise in audio equipment. The Psophometric filter is
included in the signal path to emphasize the audible parts of the
signal and attenuate signal components that contribute less to
perception of loudness.
CCITT and C-message (C-MSG) weighting filters are bandpass
filters used to measure audio-frequency noise on telephone
circuits.
None
No filter is included.
C-MSG Filter
The C-MSG is used for voice, audio, and telecommunication
applications in the U.S.
CCITT
The CCITT (ITU-T) filter is used for international telephone
circuits.
High Pass Filter
A high-pass filter (HPF) passes signals with a frequency higher
than a selected cutoff frequency.
Low Pass Filter
A low-pass filter (LPF) passes signals with a frequency lower
than a selected cutoff frequency.
De-Emphasis
Filter
This setting only applies to FM Demodulated Signals.
These processes of boosting high frequencies before
transmission, then reducing the frequencies at the receiver to
reduce noise on high frequencies, are known as pre-emphasis
and de-emphasis.
The De-Emphasis filter must match the pre-emphasis value
applied at the transmitter in order to obtain accurate
measurements.
Table 5-13 Analog Demodulation Controls and Settings (Continued)
Parameter
Description
