R.V.R. Electronica PTX1000DDS, Руководство пользователя

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/ 54 User Manual Rev. 1.0 - 29/11/16
ELETTRONICA
PTX1000DDS
7.4 Power amplifier
The final power stage is enclosed in a fully shielded metal container fixed to the
central part of the device.
The RF signal coming from the main board reached the pilot, is amplified and then
sent to the final stage which takes care of final amplification up to 1000W.
Amplification occurs in two stages, the first done with the BLF244, and the second
with a BLF147.
Besides actual RF amplification, this circuit performs other functions:
• Checks output power level depending on the setting
• Reduces delivered power in presence of high-level reflected power
• Measures direct and reflected power by means of directional couplers
• Measures the current absorbed by the power amplifier
• Measures temperature
• Filters the pass low of the output RF signal
This board also features an RF sampling of approximately -13dBm RF with respect
to the output, which is available on a BNC connector below the transmitter output
connector. Sampling is useful for verifying the characteristics of the carrier, but
not for checking those of the upper harmonics.
7.5 Panel Card
This card is located in the front end of the device and provides an interface between
the CPU card and the remaining PTX1000DDS cards.
This card handles all signals from/to LCD, Encoder, LED Indicators, Power Supply
Card, Audio Mainboard and external telemetry card, in other words, all input/output
signals of the CPU card.
The software denotes jumper positions.
7.6 Scheda CPU 16-bit
The CPU card is located at the front end of the device and is secured to the panel
card.
This card is the heart of the transmitter as it handles and processes all information
provided by the other cards and by other devices connected through the serial
interface or the telemetry card.
The 1Mb Flash Memory enables firmware update through direct connection of
PTX1000DDS RS232 output to the serial port of a PC.