Planar IT-088, Руководство по эксплуатации

Страница: 11 / 82

11
Peak Detector (PD) allows measuring the video carrier level by means of Analogue-to-
Digital Converter (ADC). The digital code of the input signal peak level logarithm is defined
as real value and is corrected in accordance with the calibration matrix of the Control Unit
(CU) microcontroller.
In digital signal demodulation mode the signal with the second IF, after Bandpass Filter
(BPF2) filtering comes to DVB-T/H Demodulator (DD), which performs demodulation and
signal parameters measurement. The measured results are processed by the Control Unit.
The Control Unit receives the commands from the user entered via Keypad, processes
the data, displays them on the LCD, and also controls the operation with external PC.
The nonvolatile memory (NVRAM) stores the calibration coefficients set by the
manufacturer, Data Logger records, and firmware utilities.
The Power Supply (PS) forms the required voltages either from batteries or from an
external power source.
In the sound check unit the signal limited by FM is transmitted from the LGAL output to
Frequency Decoder (FD). Then the low frequency signal from the FD output is amplified in
the Low Frequency Amplifier (LFA) and goes to the built-in speaker.
2.6.3. Component Arrangement
The IT-088 is made up of two components. Both modules are contained within
plastic shockproof sectional housings that also include printed and three-dimensional
wiring. MB-08 Base Unit dimensions are 200x90x55 mm. MC-088 Removable Module with
70x57x26 mm dimensions is plugged in the Base Unit and connected to it via specific
connector.
The front panel of the Base Unit contains a keypad and a graphical display. The
right panel has a serial port connector, external power source connector and an on-off
switch. The Removable Module connector is located on the back panel. The Removable
Module has a 75-Ohm input “F” connector and the connector for connection to the Base
Unit.
3. PREPARATION FOR OPERATION
Perform external examination to make sure your IT-088 is free from any visible
mechanical damage.
Upon receipt of the package, check the availability of the items contained in it against
the list provided (see section 2.5).
If the IT-088 has been kept in the environment other than the rated operating
conditions, leave your Analyzer in facilities with normal operating conditions at least for 2
hours prior to operation.
4. OPERATION PROCEDURE
4.1. Controls and Indicators
The location of controls, indicators and connectors is shown in figures 2.1 and 2.2.
These elements have the following functions:
а ) «F1», «F2», «F3», «F4» functional keys are intended for enabling the commands
corresponding to the icons shown on the screen of the IT-088;
b) «STD BY» key activates a single sweep in spectrum analyzer or bar-graph modes.
Lighting of the key indicates the power supply from an external power source;
c) « » double key controls the backlight of the screen;
d) «MENU/ENTER» key selects the current command or returns to the previous menu
level;
e) « », « », « ◄ », and « ► » arrows allow editing the current operation mode;