Cisco Systems UBR7225VXR specifications OL-17309-02

Chapter 4 Connecting the Cisco uBR7225VXR Router to the Cable Headend

Measuring the Upstream RF Signal

Figure 4-38 Vector Signal Analyzer Plot of Upstream Data Burst (Preamble Only)—Digital Demodulation Mode

Note Before moving on to Step 3, be sure to hook your spectrum analyzer back up to the upstream signal source.

Step 3 On your spectrum analyzer, narrow both the resolution and video bandwidth to 1 MHz. You will notice that the preamble of the signal has dropped in amplitude, yielding a spectrum analyzer display similar to the one in Figure 4-39.

	Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
OL-17309-02		4-33