Analog Audio Troubleshooting

Analog Audio Troubleshooting

Last updated: December 3, 2008

Possible Setup Issues

During remote operation of the analog audio measurements, you should always set the Trigger Arm to Single. The length of time required to return a measurement over GPIB using continuous triggering varies, but is always longer than when using single triggering. Continuous triggering can also cause problems when the INITiate:DONE? is used.

If any other measurements are active, turn them off or set their trigger source to Immediate.

The Detector Type selected (Peak or RMS) also sets how analog audio level measurements are displayed; as a peak value or an rms value. When comparing returned values over GPIB to your specifications, be sure to take into account the type of detector being used.

The Expected Peak Voltage is always set in V peak , regardless of the Detector Type selected, and cannot exceed 20 V peak (14.1 V rms ).

For accurate measurements, always set all the analog audio measurement setup parameters to their proper settings for the measurement being made. The SINAD and Distortion measurements typically use different settings than the analog audio level measurement. See Analog Audio Measurement Description and Analog Audio Measurement Block Diagram .

For very low level audio signals, use the 100 Hz BW BPF filter to reduce the effects of noise (see Audio Level Measurement Description ).

For accurate analog audio frequency measurements where more than one signal may be present, use the 100 Hz BW BPF filter to isolate the desired signal (see Audio Level Measurement Description ).

Interpreting Integrity Indicator Values

See Integrity Indicator .

If over range (5) is returned, the input level is greater than 4.9 dB above the Expected Peak Amplitude value or the maximum input level of 20 volts peak.

If under range (6) is returned, the input level is lower than 8 dB below the Expected Peak Amplitude value.

If the signal has both over range and under range conditions, only the over range condition (5) is indicated.