FM Signal Coverage Mapping and Path Loss Model Comparison: A Case Study of Search FM (92.3 MHz) Minna, Niger State

Abstract

Electric field strength of radio signals decreases with increase in distance from the transmitting antenna. The Electric field strength of Search FM (92.3 MHz) radio signals was measured along four radial routes from the transmitting antenna, using a Digital Signal Level Meter, GE-5499, covering the signal range of 25 – 107dBµV. Geographical coordinates and distance from the transmitting antenna were obtained at every location corresponding to each measured Electric field strength using a Global Positioning System (GPS), GPS-72. The study revealed that Search FM (92.3 MHz), the campus community radio of the Federal University of Technology, Minna, provides targeted coverage primarily within its host institution and surrounding areas. While its broadcast does not extend optimally across Niger State, the station achieves effective service delivery to its intended audience in compliance with National Broadcasting Commission (NBC) regulations. Field measurements revealed that the strongest signal quality, Grade A (signal level ≥ 60 dBμV), is confined to Gidan Kwanu, with Grade B (signal level > 30 dBμV and < 60 dBμV) coverage across most parts of Minna, and Grade C (signal level > 0 dBμV and ≤ 30 dBμV) reception in towns such as Paiko, Gawu, Kacha, Maikunkele, Kuta, and Pawa. Other regions of Niger State fall outside the coverage area. Path loss modelling was conducted to evaluate predictive accuracy of selected established models.