11
936.2332
/E
/0905
/1
1.1
6
e
Display if the output symbol rate is too low
Display if the output symbol rate is correct
Since the output symbol rate is linked to the input data rate, the setting will be controlled as to plausibility after the input
section has engaged (recognisable through the display of the code rate, e.g. 3/4). Any faulty entry will be displayed.
E.g .:
If the determined minimum value (dependent on the input signal) is not reached while setting the output symbol rate, this
will be displayed with of a flashing question mark (
?
).
If desired or possible, the symbol rate must be increased or a higher QAM stage should be selected.
White the question mark flashes, the asterisk also remains activated since no output signal is generated
(see selection of QAM stages).
If “Stuffing” is switched on, a submenu will appear on the parameter “Output symbol rate” after pressing the submenu
key . Exit from the submenu is possible by pressing the key again.
Note :
The set value of the output symbol rate is used for “PRBS” and for “Stuffing”.
The setting in one operation mode directly affects the other.
Input
1568
MHz
*
S
P
27,500
MS/s
3/4
TP
Output
S21
306,00 MHz
6,111
MS/s
!
64
QAM
Input
1568
MHz
S
P
27,500
MS/s
3/4
TP
Output
S21
306,00 MHz
6,900
MS/s
64
QAM
Main menu
Submenu for output symbol rate
The bandwidth of the output signal is particularly important for active programme filters, since several narrow signals
can be arranged within one channel of a pre-selected grid. The allocation is also possible without consideration of the grid.
The indication of the bandwidth allows for the ascertaining of the spacing of the output mid-frequency of QAM signals.
In conformity with the data rate of the suppressed programmes (programme filter), it is possible to set a bandwidth in line
with the reduced output data rate.
It can be set in 0.5 MHz steps ranging between 2.0 and 8.0 MHz with the (
+
) and (
–
) keys.
This value is converted into a symbol rate on return to the main menu.
Input
1568 MHz
*
S P
27,500
MS/s
3/4
TP
Output
S21
306,00 MHz
6,900
MS/s
64
QAM
Attention :
If the symbol rate in the main menu is not to be changed, do not set a bandwidth in the sub-
menu, otherwise the symbol rate will be adapted to the newly set bandwidth on return to the
main menu (automatic adaptation).
Note :
Some programme providers make use of the possibility of adapting the data rates of a
transponder according to the requirements, changing the baud rate of individual programmes
during transmission. The change is again compensated within the whole transponder.
If some programmes are suppressed (programme filter) and the output rate (bandwidth) has
been diminished too much, data rate peaks may produce short outages.
***
UFO 386/TP
***
Bandwidth
6.0
MHz
Suggestion
5.0
MHz
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