This study led to the formulation of two hypotheses: (a) the non-intentional emission generated by particular devices may depend on the condition of the supply voltage; and (b) non-intentional emission generated by particular devices may depend on the impedances of the supplying circuits in the point of the connection. This paper is focused on the first hypothesis related to voltage supply waveform distortion. Designated research directions can be initially confirmed by the results of similar investigations related to harmonic current emissions (0-2 kHz) under the flat-top supply waveform distortion [27], or detected differences in the performance between compact fluorescent lamps (CFLs) and light emitting diode (LED) light sources under different voltage distortions [17], as well as the effect of supply voltage harmonics on the input current of a single-phase diode bridge rectifier load [28]. However, although the above-mentioned works highlight the issue of harmonic current emissions, they do not provide information about emissions in the range of higher frequencies up to 150 kHz, nor do they express the influence of the supply voltage distortion on main signalling (usually expressed in dB\({}_{\text{H}}\)V). The unit decibel microvolt (dB\({}_{\text{H}}\)V) is directly associated with volt (V) as twenty decimal logarithms of volt divided by one microvolt. Since the subject of the research is the phenomenon of primary emission, the observation results can be expressed in volts or dB\({}_{\text{H}}\)V. It might be interpreted as a coupling coefficient in the point of the connection as a result of current emission flowing by the network impedances. Technical measures to improve transmission--that are more software-based than hardware-based--should also be considered. It is worth paying attention to the context of using machine learning techniques to solve data transmission problems. For example, in [29], the authors designed the mechanism based on the matching rule, and further traffic collision avoidance, channel occupancy, power consumption, and delay in wireless networks. This paper aims to extend the current state-of-the-art by investigating experimental cases of the influence of supply voltage waveform distortion on non-intentional emission in the range 2-150 kHz and the efficiency of selected power line communication systems. In order to achieve the proposed aim, in Section 2, the gap in the current studies related to the influence of the supply voltage distortion on supraharmonics emission and efficiency of power line communications is identified. Furthermore, in order to characterize the background of the investigation, a critical review of the emission limits, compatibility levels, and immunity tests for conducted disturbances and mains signalling in the frequency range 2-150 kHz was performed. Section 3 describes in detail the laboratory setup implemented for the experimental studies including electrical connections, the performance of programmable alternating current (AC) supply, selected devices, applied power-line communication technology as well as measurement setup for supraharmonics. Additionally, the software for frequency spectrum analysis is described in relation to current testing and measurement techniques. Section 4 presents a collection of the experimental results. First, the methodology of the investigation is presented and then the set of results of non-intentional emission for a different range of supply waveform distortion and different end-user equipment in the presence of selected power-line communications is analysed. The results describe the spectra of intentional and non-intentional emissions and the evaluation of the quality of operation of the PRIME PLC system. Distorted supply voltage conditions consist of different scenarios of the admissible harmonics contribution, in the range 0-2 kHz, including limits defined in standards EN 50160:2010 [3] and IEC 61000-4-13 [30]. Section 5 highlights crucial results and constitutes elements of the discussion.