5-3
fier is aligned such that the response at the headend is within certain
limits
from this amplifier alignment point
. So, in the reverse path the
amplifier compensates for loss characteristics in the cable in front of
it.
This is why it is best to transmit the sweep from the amplifier test
point and measure it in the headend. This ensures that the system is
properly aligned to carry signals in the reverse path.
5.1.3 Interfacing With Different Network Architectures
Single Cable - Split Band Network
The Model 3ST Sweep Transmitter or Model 3HRV Headend
Reverse Sweep Receiver is connected in the headend as shown in
figure 1. The connections are similar to those made for forward
sweep, with the transmitter output connected to the combining
network. The difference is on the input to the 3ST/3HRV. The
system signals along with the transmitted signals are tapped off and
coupled together with the reverse signals using a splitter. This
enables the 3ST/3HRV to receive both forward and reverse telemetry
and sweep (3ST) signals.
Figure 1. Single Cable — Split Band Network Reverse Sweep
Configuration With Bi-Directional Test Points.
Summary of Contents for 3SR
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