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PAMS 4000
o
utPut
symbol
r ate
, s
PeCtr al
Position
,
Code
r ate
(feC)
In this menu you can set the symbol rate, the Spectral position and the code
rate of the output signal.
—> Modulation schemes such as QPSK transmit multiple bits simultane-
ously. These are referred to as symbols. In addition to the user data
flow which transmits video and audio information, error correction
bits are transferred. The FEC number states the ratio of user bits to
the complete transmitted bits.
SYMBOL
POS 3/4
DVB-S
27500
Symbol rate:
• Use the
buttons to position the cursor under the digit of the displayed
symbol rate (5000…45000 kSymb/s).
• Press
to set the respective digit of the symbol rate.
• Repeat the procedure by the quantity of the digits to be set.
Spectral position – inverting the user signal
For exceptional cases and "older" digital receivers, the spectral position of the
user signal can be inverted "
NEG
". The default setting is "
POS
".
• Use
to place the cursor under "
POS
".
• Use
to set the spectral position to "
NEG
".
Code rate (FEC):
—> During a transmission data can be lost or changed. To recover this
data redundancy is added to the signal to be transmitted (forward
error correction – FEC). The factor of the quantity of redundancy
contained in the bits transmitted is called code rate.
Using the setting "
7/8
" you can get the highest output data rate at
lowest error correction.
• Use
to place the cursor under "
3/4
".
• Use
to set the required code rate ("1/2", "2/3", "3/4", "5/6", "7/8").
• Press the
button.
—> Return to the "output parameter" main menu – "
OUTPUT
".
Содержание PAMS 4000
Страница 1: ...Assembly Instruction PAMS 4000 ...
