In article <[email protected]>, George Stults <[email protected]> writes > I have an equation for the attenuation of a radiated signal as a > function of (distance, frequency, and environment.) > > > > ATTN = 37 + 20 Log (Freq) + 20 Log (Dist), Freq is in MHz, > Distance in Miles, Environment is free-space/line-of-sight (N=2). > > > > My information is that this equation works well for 2.4GHz > frequency range. > > > > Could anyone tell me whether this equation would still make valid > predictions for attenuation in the AM band. (535 ? 1650)Khz, and > lower? > The simple answer is no. In principle, it works best at distances long compared with the wavelength. It would work at those frequencies on a flat 'planet' with no ionosphere. > > > Or could anyone suggest an equation that would predict path loss as > a function of distance, frequency, and environment for lower > frequencies? > There are some ITU-R papers on the subject, but I don't have any up-to- date references. Try: http://www.itu.int/publications/bookshop/index.html -- Regards, John Woodgate, OOO - Own Opinions Only. The good news is that nothing is compulsory. The bad news is that everything is prohibited. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
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