CW-4142 QPSK DEMODULATOR
3.1 Using the push buttons
S
and
T
The requested parameter can be selected with the
S
and
T
buttons. With these buttons you cycle
through the available parameters (menu items).
W
and
X
, and
SHIFT
The value of the selected parameter can be
increased or decreased with the
W
and
X
buttons.
If the
SHIFT
button is pressed simultaneously, the
rate of the change is higher.
MENU
This button calls the
SELECT MENU
item, and its
second push changes between
Extended
and
Normal
menu.
STORE
The changes made to the operating parameters
can be stored with pushing this button. On pushing
the button, the demodulator writes all parameter
values into its non-volatile memory. Therefore the
STORE
button needs to be pushed once only, after
having set all parameters. The storing procedure
takes approximately 1 second. During this time the
display shows
SAVING...
.
RECALL
The data stored last can be recalled with the
RECALL
button. On pushing this button, all
parameters will be set back to their stored values.
The
←
and
→
characters appearing in the right
bottom corner of the display show whether the
actual parameter is adjustable and at the same
time they also indicate the relevant button for
change it. If none of the
←
and
→
characters
appears, the value of the selected parameter
cannot be changed.
3.2 Meaning of the front panel LEDs
DEMOD LOCKED
If this LED lights, the demodulator is receiving the
modulated QPSK carrier at proper level and it was
able to lock to the carrier. The demodulator can
only lock if the receiving frequency and the symbol
rate are set to the proper values.
LNB SHORT
This LED flashes if an error occurred in powering
the LNB. After the short circuit has been removed,
it goes out automatically.
SIGNAL LOW
This LED lights if there is no input signal or the
level of the input signal is not sufficient.
SYSTEM ERROR
This LED flashes if an error occurred in the internal
microprocessor control of the unit. After termination
of the error it goes out automatically.
4. Adjustable and query only
parameters in the normal menu
SELECT MENU
Normal
usual setting
Extended
the whole set of parameters
available
After pushing the
MENU
button, the
SELECT
MENU
item appears. On a further push the
Normal
menu will be changed to the
Extended
menu or reversed.
After switching on the demodulator, the log in is the
Normal
menu. Switching over to the other menu
can be made with the
W
or
X
button, too.
LNB LOCAL OSC.FREQ.
Available Lo values:
9.75 GHz
10.00 GHz
10.60 GHz
In this menu item the demodulator will be informed
about the local oscillator frequency (Lo) of the LNB
used with the demodulator. When using universal
LNB make sure that the transponder frequency is
within the receiving frequency range determined by
the setting of the LNB local oscillator frequency.
When setting 10.60 GHz, the demodulator
automatically outputs a 22 kHz switching signal to
switch over the oscillator in universal LNBs.
RECEIVING FREQUENCY
Receiving frequency ranges:
with Lo set to 9.75 GHz:
10700 ... 11900 MHz
with Lo set to 10.00 GHz:
10950 ... 12150 MHz
with Lo set to 10.60 GHz:
11550 ... 12750 MHz
("Lo" is the frequency of the LNB's local oscillator)
To receive a transponder, set the receiving frequency
to the transmitting frequency of the transponder.
Once the value for Lo has been set in the
LNB
LOCAL OSC.FREQ.
item, it determines the
receiving frequency range. (When attempting to set
the receiving frequency beyond the upper limit or
below the lower limit of the frequency range, the
change of the frequency will stop at the limit despite
of pushing the frequency increase or frequency
decrease button respectively.)
CARRIER FREQ. DEV.
This parameter gives the difference between the
actual and the nominal frequency of the LNB's local
oscillator. If the demodulator is locked (the
DEMOD
LOCKED
LED is lighting), this frequency difference
can be minimized by pushing the
W
or
X
button. On
this, the (nominal) frequency value set at the
RECEIVING FREQUENCY
menu item will be
corrected for optimal reception.
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