Generator R&S
UP300/350
E-1147.2759.00
6-138
Operating Manual, 11/2007
6.2.2.2.5
MOD DIST (Two-Tone Signal in Accordance with IEC)
Description
In the MOD DIST menu, you can set the function parameters for the two-tone
signal. The two-tone signal is produced by superimposing 2 sinewave
signals: low-frequency interference signal and high-frequency useful signal.
The interference signal is 1 to 10 times larger than the useful signal.
The signal is used for intermodulation measurements as defined by SMPTE
(Society of Motion Picture and Television Engineers) and for modulation
factor analysis according to DIN IEC 268-3.
Recommendation of DIN IEC 268-3:
Interference signal f
1
is between 0.5 and 1.5 octaves above the lower limit
frequency f
u
of the DUT:
f
u
+ 0.5 octaves = f
1
= f
u
+ 1.5 octaves
Useful signal f
2
is between 0.5 and 1.5 octaves below the upper limit
frequency f
o
of the DUT:
f
o
- 1.5 octaves = f
2
= f
o
- 0.5 octaves
f
2
= 8 x f1
SMPTE standard:
Interference signal: f
1
= 60 Hz
Useful signal: f
2
= 7 kHz
Amplitude ratio of interference signal to useful signal:
4:1 (SMPTE standard); 10:1 also possible according to DIN
Summary of Contents for Smart Instruments UP300
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