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CW-4142 QPSK DEMODULATOR
3.1 Using the push buttons
The requested parameter can be selected with the
and
buttons. With these buttons you cycle
through the available parameters (menu items).
and
The value of the selected parameter can be
increased or decreased with the
If the SHIFT button is pressed simultaneously, the
rate of the change is higher.
This button calls the SELECT MENU item, and its
second push changes between Extended and
Normal menu.
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....
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
and
, and SHIFT
and
MENU
STORE
RECALL
goes
out
automatically.
4. Adjustable and query only
parameters in the normal menu
Normal
Extended
available
After pushing the MENU button, the SELECT
buttons.
MENU item appears. On a further push the
Normal
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
Available Lo values:
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
automatically outputs a 22 kHz switching signal to
switch over the oscillator in universal LNBs.
Receiving frequency ranges:
with Lo set to 9.75 GHz:
with Lo set to 10.00 GHz:
with Lo set to 10.60 GHz:
("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
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.)
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
this, the (nominal) frequency value set at the
RECEIVING FREQUENCY menu item will be
corrected for optimal reception.
3
SELECT MENU
usual setting
the
whole
menu
will
be
or
button, too.
LNB LOCAL OSC.FREQ.
9.75 GHz
10.00 GHz
10.60 GHz
setting
10.60
GHz,
RECEIVING FREQUENCY
10700 ... 11900 MHz
10950 ... 12150 MHz
11550 ... 12750 MHz
OSC.FREQ. item, it determines the
CARRIER FREQ. DEV.
set
of
parameters
changed
to
the
the
demodulator
or
button. On
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