For Sale: Rohde & Schwarz UPD Audio Analyzer

Rohde & Schwarz UPD Audio Analyzer, 2 Hz - 300 kHz

The R&S UPD Audio Analyzer performs practically all types of audio measurement, from frequency response measurements through to externally controlled sweeps with reference traces, determination of 3rd-order difference frequency distortion, spectral display of demodulated wow and flutter signals, etc. In contrast to many other audio analyzers, the R&S UPD is capable of performing real dual-channel measurements in the audio-frequency range, ie there is no need for switchover between two inputs and this type of measurement is not limited to a few special cases.

The generator is every bit as versatile: it supplies any conceivable signal from sinewave and noise signals through to multi-sinewave signals comprising up to 7400 frequencies.

In addition to all this, the UPD Audio Analyzer features excellent technical data: analog sinewave generation with harmonics of typ. -120 dB, spectrum displays with a noise floor below -140 dB for analog and -160 dB for digital interfaces, FFT with a maximum frequency resolution of 0.02 Hz, etc.

The R&S UPD provides signal monitoring via loudspeaker, jitter measurements on digital audio signals, resynchronization of jittered digital audio signals by means of a jitter-free clock signal, and many more features.

The Rohde & Schwarz UPD Audio Analyzer performs all measurements using digital signal processing. Analog signals to be tested undergo elaborate preprocessing before they are digitized and measured by means of digital routines. For example, in THD measurements, the fundamental is attenuated by means of a notch filter and the residual signal amplified by 30 dB before it is digitized. In this way, the dynamic range can be extended beyond that offered by the internal converter. This provides sufficient margin for measuring converters of the future, which will be technically more advanced than those of present-day technology (see graph on the right). This concept guarantees performance and flexibility by far superior to instruments providing purely analog or digital measurements.

Features of the R&S UPD Audio Analyzer include:

• The test routines for analog and digital interfaces are identical. This allows, for instance, the direct comparison of IMD measurements made ahead of and after a converter
• All test functions are available both on the analog and the digital interfaces. This makes it possible to measure at any point of a common analog and digital transmission path. Only this ensures efficient and complete testing
• The filters, too, are implemented digitally, resulting in an infinite number of filters as it were, and this also for measurements on analog interfaces. Simply choose the type of filter (eg highpass), cutoff frequency and attenuation: that’s all you have to do to loop a new filter into the test path
• In intermodulation measurements, spurious components are measured selectively for all frequencies in accordance with the mathematical formula of the relevant test standards. This procedure avoids the measurement of adjacent components along with the spuria, which is usually inevitable with analog test methods
• Measurement speed is as a rule higher than with analog techniques since digital test routines can adapt their speed to the input frequency.
• Operation is the same for the analog and the digital interfaces. A feature that should not be underestimated