Setup Manual

Device View Description
R&S
®
Tx9
161Operating Manual 2109.9110.02 ─ 07
Sound phase shifter
Only available for analog TV standards
The sound phase shifter modifies the phase of the sound subcarrier as a function of
the low-frequency modulation of the picture signal.
When the sound phase shifter is switched on, its characteristic is determined using two
onset points.
The reference for setting the position is initially a value of 37.5 % for the back porch.
Smaller values are in the range of the sync pulse, whereby a value of 15 % corre-
sponds to a sync‑pulse amplitude of 300 mV. Larger values are in the picture range,
whereby a value of 90 % corresponds to a picture amplitude of 700 mV.
An additional condition is that the setting for onset point 1 must always be greater than
that of onset point 2. The sharpness of the two onset points is determined by the slope
of the characteristic at these points. The magnitude of the setting determines the mag-
nitude of the phase shift, whereby a setting of 50 % specifies the maximum value. The
sign of the setting value determines whether the phase is shifted in the positive or neg-
ative direction.
When the characteristic is calculated, it is divided into three linear areas by the two
onset points.
No phase shift takes place for modulation of the picture signal in the area between the
two onset points, i.e. a correction phase of 0° is set.
A correction phase unequal to 0° is set in the case of picture signal modulation which is
greater than the position of onset point 1. The characteristic in this area begins with a
correction phase of 0°, with modulation corresponding to the position of onset point 1,
and increases linearly up to the maximum phase set with slope 1, with 100 % modula-
tion of the picture signal.
Similarly, a correction phase unequal to 0° is also set in the case of picture signal mod-
ulation which is smaller than the position of onset point 2. The characteristic in this
area begins with a correction phase of 0°, with modulation corresponding to the posi-
tion of onset point 2, and increases linearly up to the maximum phase set with slope 2,
with 0 % modulation of the picture signal.
"Non Linear" parameters
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Exciter ATSC