Chapter 11
Measure Mode – Sweep Tab
Reverse Sweep
280
DSAM Help User Guide
Rev. 001
The Reverse Sweep plan, like the forward sweep plan, is configured
in the SDA headend/hub units and communicated to the DSAM field
unit over forward telemetry.
Sweeping the reverse path is a little different from sweeping the
forward path. The lower reverse frequencies are not attenuated in
cable as much as the higher forward frequencies. In sweeping the
forward path, the amplifier is aligned so the amplifier compensates for
the cable before it, i.e. the cable segment between test point (the
output of the amp) and the next amp down the network. Sweeping the
reverse path, the amplifier is aligned so the response at the headend
is within certain limits set by engineering. The amplifier is aligned to
compensate for loss characteristics in the cable between the test point
(input to amp) and the next amp closest to the headend.
Running a
Reverse Sweep
To run a Reverse Sweep
1
Press
Measure
.
2
Press the
Sweep
softkey.
NOTE
There are two sweep configuration possibilities to consider:
Bi-directional
– If Reverse Sweep is configured to use one port, be
sure to connect the cable to Port 1.
Reverse Port
– If Reverse Sweep is configured to use both ports,
be sure to connect both cables to the test points.
See
for more information.
Figure 251
Measure Mode – Sweep Tab
21128026 R001 DSAM Help User Guide.book Page 280 Thursday, February 5, 2009 2:02 PM
