Sunrise Telecom, Hukk Division
Page 45
DIGITAL
The DIGITAL main level button sets the CR1200R in digital
mode for testing 64 or 256 QAM digital signals. The CR1200R
not only measures ITU-T J.83 Annex B digital signals, but will
measures levels of other digital signals such as QPR and QPSK as
well. Depressing the DIGITAL key on the front panel will bring
up the screen shown in Figure 3-32. However, if the Channel Plan
shows the selected channel to be other than a digital channel, the
screen shown in figure 3-33 will appear. This screen indicates that
the channel is not properly set up as a QAM channel. The unit will
not lock to a 64QAM signal if the channel table is set for
256QAM and vise versa. The channel tables must be properly pro-
grammed.
F
IGURE
3-32
F
ORCE
QAM M
ODULATION
If the CR1200R is tuned to a digital signal not programmed in the
current channel plan the CR1200R opens up the force modulation
screen as shown in Figure 3-29. This allows the operator to
quickly force the CR1200R to 64 QAM or 256 QAM signals.
Pushing the FORCE 64-QAM (F1) function key forces the
CR1200R to demodulate the signal as a 64 QAM signal. The
FORCE 256 QAM (F2) function key forces the CR1200R to de-
modulate the signal as a 256 QAM signal.
It is highly recommended that you take the time to set up a current
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