Chapter 10 - Upstream Generator
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10.2.2.2
Setting the number of upstreams
The amount of carrier can vary between one to eight. All not with an * marked carriers are active
and can be transmitted. With the F-Key
ACTIVATE
can the selected upstream activated or
disabled (with * marked) for the transmission.
10.2.2.3
Entering the frequency
After selecting the
FREQUENCY
menu item, use the numeric keypad or the arrow keys to set a
frequency between 5 MHz and 85 MHz or 204 MHz. The smallest frequency resolution is 0.1 MHz
(100 kHz).
The decimal place of the current cursor position can be changed from 0-9 by pressing the arrow
key
↑
/
↓
. The cursor can be moved to the left and right using the
←/→
keys. Use the
ENTER
key to
confirm the entry. If the value entered is beyond the valid range it is limited to the corresponding
minimum and/or maximum value.
10.2.2.4
Entering the transmission level
After selecting the
LEVEL
menu item, use the numeric keypad or the arrow keys to set a level
between 70 and 112 dBµV. The lowest level resolution is 1dB.
The decimal place of the current cursor position can be changed from 0-9 by pressing the arrow
key
↑
/
↓
. The cursor can be moved to the left and right using the
←/→
keys. Use the
ENTER
key
to confirm the entry. If the value entered is beyond the valid range it is limited to the corresponding
minimum and/or maximum value.
10.2.2.5
Common transmission level
The level difference between two carriers is limited to 16dB. To avoid to change each carrier
individual you can use the F-Key
ALL LEVELS
to manipulate all carriers at once. As soon as that
Key is active, you can enter a new value and after pressing
ENTER
the value will be used for all
carriers.
Figure 10-10 Upstream Generator change common transmission level
10.2.2.6
QAM-modulation order
At activated modulation (non CW mode) a PRBS sequence will be transmitted. You have the option
to change the order of the QAM modulation with the F-Key
MODULATION
. This is only for the first
eight carriers possible, the last one (number 9) is an OFDM carrier. You can choose between
QPSK
,
16QAM
,
64QAM
and
256QAM
.
