Abstract
In this paper, the capacitance, attenuation and power ratings of some Hitachi HF cables commonly used in RF communications were computed and compared with the manufacturer’s data. Results obtained were compared with the values presented by the manufacturers as obtained from published literature using Spearman’s correlation. The computed Spearman’s correlation coefficients ranged between 0 and 0.999 which is in line with the theory that there is a strong positive correlation between the computed and manufacturer’s values. The graphs of power rating against frequency and attenuation against frequency of the 50Ω and 75Ω cables were plotted. The slight differences in the computed and manufacturer’s values when compared are insignificant in practical coaxial line transmission as they amount to negligible losses only. In line with theory, the computed values show that attenuation with increase in frequency. Coaxial cables with larger diameters offer lesser attenuation for high frequency signals. Power rating decreases with increasing frequency. The computed values of the 75Ω coaxial cables upholds the manufacturers assertion that they have lesser attenuation compared with the 50Ω coaxial cables which is why they are preferred in HF, VHF and UHF communications although 50Ω cables have higher power rating and are more useful in AM transmission.
Keywords: Characterization, comparative Study, coaxial cables, spearman’s correlation