Path loss measurement and modeling are necessary for selecting or developing suitable propagation models for specific radio environments. In this work, the signal power of six ultra-high frequency (UHF) digital broadcast transmitters was measured and variation of signal power was modeled. Measurements were obtained using a low-cost testbed made up of a global positioning system module and a Realtek software-defined radio (RTL-SDR) configured as a spectrum analyzer. The study was carried out in Nigeria's Adamawa and Bauchi States along twelve distinct routes. The path loss exponent, path loss intercept (determined by the mean free space attenuation), and log-normal shadowing variable for each route were determined. The average path loss exponents for the three transmitters in Adamawa, operating at 470, 522, and 538 MHz, are 1.71, 1.84, and 1.81, respectively. In contrast, for the transmitter in Bauchi operating at 634, 642, and 650 MHz, their respective average exponent values are 1.19, 1.18, and 1.21. A log-normal path loss model was developed and compared with the measured data and established empirical path loss models. In comparison to the empirical path loss models, the log-normal model offers a better root-mean-squared error performance. Additionally, a graphical comparison demonstrates that the Okumura-Hata model tends to overestimate the data whereas the log-normal model offers the best fit for the data. In contrast to the Okumura-Hata model, the Egli propagation model tends to underestimate the measured data.