Total posts : 45366
The gentleman I referred to in my last post relented, and agreed to test the apparent reciprocity failure which is the subject of most of this thread. At first, he did not think that the subject merited any discussion at all, because, as anybody who knows anything about antennas knows, any antenna has the same gain receiving as transmitting. During his four decades as the head of an antenna laboratory, he has tested numerous full-sized antennas, and also many microwave models of larger antennas, and he had never encountered an antenna where this rule did not apply. What caused him to agree to look into my claims is that I attributed my statements to the great Kenneth A. Norton, and he was curious to know what Norton was talking about. This gentleman knew Norton (who, he told me, is only recently deceased) personally, and he respected Norton’s work.
I asked this gentleman to do an NEC simulation of the kind that I did (and described in this thread) to prove the theory. He told me that he does not use NEC because he considers it to be inaccurate, so he did the simulation using wipl-d instead. Here are the results of the wipl-d simulation:
For two quarter-wave monopoles operating at 1 MHz at a separation of 10000 meters (the monopole lengths set to give a real input impedance [i.e. only resistance, and no reactance]), the transmitting monopole was found to have a gain of 3.27, or 5.15 dBi, and the receiving monopole gain was found to be 0.82, or – 0.85 dBi. The receiving monopole gain was not the same as the transmitting monopole gain, and so the postulated reciprocity failure was confirmed.
Anybody wishing to get the paper by Norton that I mentioned in this thread may be able to get it free-of-charge from their local public library through what is called “interlibrary loan.” If your local library does not have this paper, they may be able to get it for you from another library. One relatively small library I know of that has this paper on file is Broward County Main Library, Ft. Lauderdale, FL. The Newark, N.J. Public Library, which is also small (and underfunded), also has an excellent reference department. Of course, the enormous N.Y.C. Public Library must be magnificent. The libraries in even moderately-sized cities have many scientific journals in their reference departments. It takes about 2-3 weeks to get a paper through interlibrary loan