Quote para 2, both points: Reciprocity still applies with respect to gain and off axis effects. If the receive antenna is down by 3dB, it will be down by 3dB EIRP when transmitting; if down by 10dB, the EIRP will be down 10dB.
Quote para 3: Local noise does make a real difference and will compromise reciprocity. Top quoted only by list policy. Kok Chen wrote: > Although Reciprocity Theory states that if both of you use the same > power, the received power at the two antenna terminals will be the same > independent of what antennas are at each end, other things determine if > he can copy you better than you can copy him. > However, another factor, arguably more important, is the antennas' > directivity and where the directivity are aimed at. If his antenna is > more directive than yours by 3 dB, all else being equal, he has a 3 dB > of SNR advantage. If the arrival angle of his signal at your antenna is > 10 dB below where your antenna actually peaks, while your signal arrives > at his antenna where the response of his antenna peaks, you have yet > another 10 dB disadvantage, etc. > The same SNR argument applies to how noisy his local RF environment is > compared to your environment. -- David Woolley "we do not overly restrict the subject matter on the list, and we encourage postings on a wide range of amateur radio related topics" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
