Keysight U8903B, Service Manual

Page: 51 / 165

Performance Verification for Analog Analyzer 3
Keysight U8903B Service Guide 51
– Measurement function3: THD Ratio
– Measurement function4: AC Voltage
– Sample size: 131072
– High pass filter: 20 Hz
– Low pass filter: 20 kHz
4 Enable the U8903B analyzer input channels to be tested.
5 Record the THD+N ratio measurement on the audio analyzer for each tested channel in
the “
Test record for distortion verification ” on page 114 .
6 Compare the recorded THD+N ratio measurement value to the specification. If the test
fails, adjustment will need to be carried out accordingly.
SMTPE IMD verification
This test verifies the SMTPE IMD performance of the U8903B analyzer by using an internal
loopback connection to ensure that it is within the published specification.
1 Preset the U8903B audio analyzer. Configure the U8903B generator output channel 1
and 2 to connect to all of its own analyzer input channels (up to 8 channels
concurrently) through internal loopback.
2 Configure the U8903B generator output channels as follows:
– Connection type: Unbalanced
– Output impedance: 600
Ω
– Output grounding configuration: Floating ground
– Waveform: SMPTE 1 to 1
– Output state: ON
3 Configure the U8903B analyzer input channels to be tested as follows:
– Connection type: Loopback
Table 3-8 SMTPE IMD specification
SMTPE IMD specification (at 1 Vrms) Equipment used
≤− 95 dB U8903B (internal loopback)
NOTE
Power on the U8903B audio analyzer for at least 30 minutes before performing the
performance verification.