Adtec digital EN-91 / EN-91P (version 1.02.29) Manual - Manual (Page 17)

optimize protection.
Rolloff The Rolloff selection will determine the
shape of the output filter. The occupied
bandwidth of the modulated signal is the
symbol rate multiplied by (1+α) where
alpha (α) is the rolloff factor. By using a
lower alpha, carriers can be spaced closer
together on a given transponder or an
increased symbol rate can be realized for
a given bandwidth.
5 (requires feature key)
10 (requires feature key)
15 (requires feature key)
20
25
30
Pilot When operating in DVB-S2, the Pilot
options are either ON or OFF. When pilots
are enabled, the total data throughput is
reduced by approximately 3.0%.
On
Off
Rate
Priority
The Rate Priority control allows the
operator to designate which rate will be
kept constant. When the Symbol Rate is
entered and Rate Priority is Symbol, the
symbol rate is held constant and the
Interface rate is calculated. When the
Interface Rate is entered and Rate Priority
is Interface, the interface rate is held
constant and the symbol rate is
calculated.
Symbol
Interface
Symbol
Rate The number of symbols transmitted per
second. The amount of data per symbol is
dependant upon the modulation type, e.g.
QPSK, 8PSK, etc.
Range can be determined by
feature key.
Interface
Rate
The Interface Rate is the bit rate at the
baseband interface.
Range can be determined by
feature key.
Carrier
Mode The Carrier Mode control allows the
operator to select ON for normal
operations or select one of four
unmodulated carriers. The Pure Carrier
option will provide an un-modulated
output carrier at the desired frequency
and output power. Other Carrier Mode
options include Clock 4/8/16.
Pure Carrier
On
Clock/8
Clock/4
Clock/16
10Mhz
Clock
Allows operator to generate or pass a
10Mhz signal. The signal can be
generated internally or sourced externally.
OFF
ON
EXTERNAL