User's Manual

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User Manual
Rev. 2.3 - 26/06/19
PTRL-LCD & RXRL-LCD
ELETTRONICA
7.3 Reducing card
The reducing card transforms the voltage, coming from the switching power supply,
from 24V to 12 V which is the necessary voltage for the supply of the RF power
stage of the unit.
7.4 Panel card
The pannel card contains the microprocessor (PIC16F877Q) which implements
the monitoring software of the unit, the display and the other elements which are
necessary for the interface with the user.
This card is the interface with the other modules of the unit, both for the distribution
of the supply units and monitoring and for the measurements.
7.5 Monitoring card
The monitoring card provides for the management of the readings and the regulation
of the parameters referring to the direct and forward power, monitors the gain and
the “FOLDBACK” input and it surveys the internal temperature of the unit.
The card works as an interface between the panel card and the final stage for the
power regulation, the protection, the readings and the remote monitorings.
7.6 Main card
The main card has the following functions:
• Processing of the audio and SCA inputs
• Generation of the carrier
• Modulation
• R.F. Amplifier (Driver)
The difference between the Mono and Stereo versions of this card is the audio
stage, since the stereo version contains a stereophonic coder.
7.6.1 Audio input stage (mono version)
The audio input stage contains the circuits which realize the following functions::
• Selection of the input impedance
• 15 kHz filtering of the mono channel
• Preenfasis of the mono channel