The aim of this paper is to study the different parts of a wireless system in order to better understand the signal properties and what key factors changes the signal during its transmission. Two transmitters were created, an FM transmitter that transmits analog data and an Arudino board programed to convert data to bits before its transmission. The acquired signals were then compared to the original signal noting how differently the data had changed. To understand the antennas contribution to the system a simulation was done using High Frequency Structural Simulator. A description of the analysis on the different acquired signals was done to determine the best applications they might have.

FM transmitter APRS of telemetric data is device able to measure telemetric values from its ambient. It is able to send this data to user on earth by radio frequency channel. This device can create data frames, with proper formatting allowing sending data. It operates in 435 MHz band, uses FSK and AFSK modulation. This work describes basic information of used protocols, electronic connection of this transmitter and software equipment.