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SDA-5500/SDA-5510 Sweep Configuration: Configuring Reverse Sweep

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sweeping in the forward direction will experience a slightly slower sweep

time.

Basic Reverse Sweep Procedure

Sweeping the reverse path is a little different from sweeping the forward

path. Because the system is designed with appropriate spacing for the

forward high frequency range, the reverse path may not require amplification

at each station. The lower frequencies aren’t attenuated in cable as much at

the higher frequencies. In sweeping the forward path the amplifier is aligned

such that its output is within certain limits (the amplifier compensates for the

cable behind it). However in sweeping the reverse path the amplifier 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 after 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.

Wiring Connections

Single Cable - Split Band Network

The SDA-5500 or SDA-5510 is connected in the headend as shown in

Figure 14-10. The output is connected to the combining network. At the

input, the system signals, along with the transmitted signals, are tapped off

and coupled together with the reverse signals using a splitter. This enables

the SDA-5500 to receive both forward and reverse telemetry and sweep

signals (the SDA-5510 can receive the reverse telemetry and sweep

signals).

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Wavetek 147 Specifiche Pagina 309

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