User`s manual

Table Of Contents
17 WOW AND FLUTTER
17.1 INTRODUCTION
Within this menu Wow & Flutter measurements are possible, meeting both IEC and
NAB standards. Basically, what is measured is the frequency modulation that
follows instantaneous speed variations due to mechanical imperfections in analog
recording or playback devices. Differently than in traditional Wow & Flutter
analyser the whole measuring process is taken digitally without relying on analog
FM discriminator, filter and detector with much higher accuracy, limited by the clock
quartz only. Furthermore, aside traditional number data, a time graph is presented
as well as a Frequency Domain Analysis of the demodulated signal. The latter
feature greatly simplify locating the cause of problems, once rotating speed and
mechanical circumference of eventually defective rotating parts are known. Carrier
frequency can range form 1500Hz to 6000Hz. This is important if you record
directly the test signal. Using existing test support, IEC specify a test frequency of
3150Hz, NAB of 3000Hz.
17.2 WOW & FLUTTER CONTROL PANEL
Figure 17.1
17.2.1 TOOLBAR BUTTON
Starts a Wow & Flutter analysis.
Enables weighting filter in the time domain windows. Frequency Domain remains
unaffected. Works both when the analysis is running or as a post process.
Switch to Time Domain.
Switch to Frequency Domain.
17.2.2 TOOLBAR DROP DOWN LIST
Input channel
Selects the input channel configuration
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