Televes Serie H-30 - Manual (Page 15)

EN
15
5. Spectrum
Real-time processing speeds ensure capture of any
fast, intermittent plant impairments.
Due to the accuracy and level of detail provided
by this spectrum analyzer, the H30 is the ideal tool
for identifying and locating noise, interference,
ingress and other waveforms that may be affecting
cable services quality.
5.1. Main window
Below is a capture of a Spectrum window with a
brief explanation of its features:
Span
User can change it using
(+) or (-)
List of
measurements
with pass/fail
indicators
Reference level
(Auto)
Selected channel
Change using
5.2. Setup
Press to change Spectrum options.
- Span: 2.5MHz, 6.25MHz, 12.5MHz, 25MHz,
62.5MHz, 125MHz, 250MHz, 500MHz, Full.
Set the span of the spectrum. To easily change
the span, use the OK Button to decrease the
span and the Back Button to increase the span.
- dB/div: 5 dB/div, 10 dB/div
- Tuning: Channel, Frequency
- A/D: Auto, Analog, Digital.
- Save datalog: Saves the current scan
measurements. You can see the datalogs
using the remote control application.
6. Constellation
Digital video often does not show signal
impairment until it is too late due to the small
margin between acceptable quality and failure.
Constellation diagrams are an indispensable tool
to help detect the presence of noise, phase jitter,
interference, and gain compression, all of which
impact overall signal quality and thus reduce
Modulation Error Ratio (MER).
Ideally, each of the symbols in a constellation
diagram should display a clean dot indicating a
perfect QAM signal.
The H30’s real time constellation, allows the
installer to assess the size and shape of the build
up of dots indicative of problems which contribute
to bit errors leading to service disruption