2. GENERAL DESCRIPTION AND PRINCIPLE OF OPERATION
2.1. Introduction
This Operating Manual is intended for introducing the design, functions, and basic
instructions related to operation and servicing of the IT-081 TV Level Meter (Meter).
The IT-081 is designed for control and adjustment of television and broadcasting
distribution networks as well as of separate components of such networks, or other
electronic devices.
The Meter allows measurement of channel power and parameters of TV
signal.
The Meter can be used both in laboratory, powered by an external power source, and
in field, powered by batteries.
The Meter can also operate as a part of Return Path Test and
Measurement Set.
The reliability of the IT-081 is ensured by fulfillment of regular maintenance
procedures. These procedures and their intervals are described in Section 5.
In this manual the following abbreviations are used:
- PC - Personal Computer;
- CD - Compact Disk;
- LCD - Liquid Crystal Display;
- ADC - Analog-to-Digital Converter;
- IF - Intermediate Frequency.
2.2. Safety Precautions
Thoroughly inspect the product and carefully read the related documentation to get
acquainted with all the safety markings and instructions before you start to operate the
Meter.
WARNING
Only trained service personnel aware of the hazards involved should perform
repair on the Meter.
CAUTION
Tuning the Meter and replacement of the components that influence the
accuracy of measurements without service personnel is strictly prohibited, since the
components used in the Meter are purpose-made and their replacement will result in
inaccurate operation of the Meter. To exclude the possibility of mechanical damage to the
IT-081, the instructions regarding the storage and transportation (see Sections 7 and 8) of
the Meter must be observed.
2.3. Function
The IT-081 TV Level Meter belongs to the family of IT-08 measurement instruments
and is intended for measurement of the video carrier level of standard TV signal.
The Meter offers the following measurement modes for analog channels: video
carrier to audio carrier (V/A) ratio, and video carrier to noise (C/N) ratio. For digital
channels the measurement modes are the following: channel power and C/N ratio.
The IT-081 can be connected to a personal computer to access additional modes.
The IT-081 operates in spectrum analyzer mode displayed on the built-in LCD. The Meter
allows measuring direct and alternating voltage of the remote power supply of the TV and
broadcasting distribution networks.
The appearance of the Meter and its components are displayed in figures 2.1 and
2.2.
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