In the first part of my essay I will demonstrate the Tetra radio system. I will describe the role of the TETRA system in Budapest Metro Line 4 subway automatic management. I will mention the underground radio coverage problems caused by the leaky feeder. Then I will describe the chips and patents used for the system development for radio frequency coverage meters. Accompany an engineering job from design to implementation. I will touch upon circuit plans and realizations. I will also demonstrate the manufacture and design of the microcontroller program. I have designed the database for the instrument calibration and I will show the results of these tests. For calibration and instrument testing I used the generator found in lab#504 of the V1-Building.
Development of these tools can make it possible to detect any problems in the Metro tunnel. Another practical use of this calibration database would be in the instrument software and antenna planning, in addition to testing compact designs in real life situations.