Wavetek 147 Specifikace stáhnout pdf (Strana 44)

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Description and Basic Operation: Basic Modes of Operation

service and in-channel. This allows you to measure the performance

customers really experience, all without any service interruption.

Carrier-to-noise is measured using an

advanced “quiet line” algorithm. The meter

searches for a line of video with no active

signal (this typically happens on one or more

lines during vertical sync of an analog video

channel). This allows the noise measurement

to be made in the middle of the channel rather

than in an unused side band, so the reading

reflects what the CATV subscriber actually

sees.

Hum is also measured in-service using

DSP algorithms. Pre-programmed filters

help isolate power supply problems to 1-

times power-frequency, 2-times power-

frequency, or all low frequency

components.

Depth of modulation can be measured in-

service. This display also allows the user to

listen to either AM or FM audio carriers to help

identify a signal or to troubleshoot some types

of problems. If a steady ingress source is

found, this feature can be used to help find out

what is leaking into the cable network.

The SDA-5000 also offers the capability to perform these proof-of-

performance tests on an automated basis. You can perform a complete

battery of tests for any or all channels in the channel plan. The meter can

perform these tests immediately, or it can perform a set of tests over any set

of intervals you desire. This is useful when you’re running the 24-hour tests

required by the FCC in the US, and by other international governing bodies.

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Wavetek 147 Specifikace Strana 44

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