Imperfections in the theoretical NSA model can adversely or favorably affect a site validation measurement and a proposal for correction factors for broadband biconical antennas

It has been shown that the normalized site attenuation (NSA) test as described in ANSI C63.4 has up to 2.5 dB of error in the model when biconical antennas are used from 30 to 200 MHz. These error values have been predicted through numerical modeling techniques. The numerical model was empirically validated for biconical antennas using both 200:50 ohm balun transformers and 50:50 ohm balun transformers. The empirical validation testing was conducted on seven antenna pairs of biconical antennas of different makes and models. Based on this work, the American National Standards (ANS) Committee C63 is reviewing proposed changes to the ANSI standards to improve the current NSA model.