User manual

Appendix A: Specifications
A-46
AM700 Audio Measurement Set User Manual
Table A-22: FFT Analyzer (Cont.)
Capabilities Description
Multitone
Multitone Detection Each channel can be set to recognize one multi-
tone, which can either be the current tone in one
of the generator channels or a multitone de-
scribed in a file.
Files are provided in the AM700 file system that
contain multitone specifications for the Tektronix
ASG 100/140 audio generators.
Minimum Multitone Detection Level –60 dBu
The minimum detection level is for individual
tones that make up the multitone signal. The
generator amplitude readings are 0.707 x peak
voltage, which is RMS voltage for sine waves
only. The level of transmitted multitones depend
on the crest factor of the signal, which varies
each time the multitone signal is computed
(unless in file mode with absolute phases
provided).
In both file mode and list mode, the amplitude
parameters for individual tones are only used to
control the relative amplitude of the tone with
respect to the other tones.
The only way you can determine the received
level of each tone is to work backwards from the
peak level of the complex waveform, with knowl-
edge of the crest factor.