Viavi CT-4 Getting Started Manual

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CT-4 and CT-X Quick Verify

Determine Estimated CT-4 and CT-X Levels

This procedure is not to be used to set or adjust the CT-4/CT-X levels but to verify if the

measured level is within the appropriate limits and determine the CT-4/CT-X needs to be

adjusted.

Note: We will only look at the two typical frequencies in this document.

Prerequisite

Please Review CT-4 Getting Started Guide

Please Review CT-X Getting Started Guide

System Requirements

ONX 620 or ONX630

Any forward test points

Quick Review

CT-4 has a fixed injection of 138 MHz and 612 MHz See Figure 1

Figure 1: Typical injection Frequencies

Procedure

Measure adjacent QAM Channels to 612 MHz and 138 MHz

•Ch. 88 or 89, and 16 or 17 respectively

•Log channel power levels for each

•Measure the peak value of the dual CW's combined (Not in Low-Res mode)

•612 MHz and 138 MHz

•Log peak value of both frequencies

Page 1 CT-4 and CT-X Quick Verify Determine Estimated CT-4 and CT-X Levels This procedure is not to be used to set or adjust the CT-4/CT-X levels but to verify if the measured level is within the appropriate limits and determine the CT-4/CT-X needs to be adjusted.
Page 2 Proper Levels, no action required •Ch 88 or 89 power level -24 dBc to -25 dBc = acceptable level •Ch 16 or 17 power level -24 dBc to -25 dBc = acceptable level If any of the above is not true, schedule headend visit Connect signal to port 1 of the ONX CATV Home Screen select...
Page 3 ONX builds channel plan and provides measurement for all channels in the plan Figure 2: Channel Check Start Note the Power Level of the selected Channels...
Page 4 Downstream Spectrum Setup (612 MHz) Downstream Spectrum Setup (612 MHz) Continued...
Page 5 Downstream Spectrum Setup (138 MHz) Downstream Spectrum Setup (138 MHz) Continued...
Page 6: Measured Results
Measured Results (612 MHz) (138Mhz) Note: These are approximate levels to verify leakage levels are within the expected limits. If levels are off by 3 dB too low, then leakage readings will be cut by ½. Example: A 20 microvolt leak would by only 10 microvolts.

Ct-x