Viavi CX100 ComXpert Operation Manual page 129

Chapter 5 RF Instrument Function Descriptions
RF Test
5.2.7.4 Audio Measurements
Audio measurements are supported in Duplex Test and Rx Test modes of operation. The
CX100 contains the following Audio meters:
Audio Level Meter
The Audio Level meter indicates the signal voltage or power of the received
audio signal. The measurement is used to evaluate the power performance of the
transmit device.
(Audio) Distortion Meter
The Distortion meter is used to detect and isolate any frequencies that are
causing distortion on the incoming audio signal. The Distortion meter displays
the difference between the incoming audio signal in relation to the transmitted
signal. The differences detected are a result of extraneous signals present in the
audio signal (i.e., noise, external signals).
(Audio) SINAD Meter
SINAD measurements are typically used to determine receiver sensitivity, but they
can also be used to determine how a transmit signal is degraded by noise and
distortion. The SINAD Meter displays the ratio Signal + Noise + Distortion divided
by the sum of Noise + Distortion, the result of which is displayed in dB.
(Audio) SNR Meter
Signal to Noise (SNR) measurements compare the level of a desired signal to the
level of background noise. SNR is defined as the ratio of signal power to the noise
power.
AF Counter
The AF Counter measures the number of oscillations present in the received
audio signal. The AF Counter is used to perform tasks such as measuring the
frequency of a carrier signal or measuring the frequency accuracy of the incoming
signal.
Rev 002
5 - 20
Offset Applied Indicator
An offset indicator is displayed on the Audio Level meter measurement
meters when external attenuation is applied.
CX100 ComXpert Operation Manual 22144015
August 2023