In this article. the frequency-modulated signals have been analyzed in the spectrum. with the aim of reviewing the performance of these systems to guarantee the quality of the service in the Radiocuba company. The NooElec NESDR Nano 2-Tiny Black RTL-SDR USB Set device (RTL2832U + R820T2) has been used to analyze the levels of field strength. https://foldlyers.shop/product-category/light-meters/