The sample caclulations seen here are for the SETI League Hydrogen Line Feedhorn, as discussed in this article . 13 Dec 1997 parabola.xls Calculates the electrical performance of a parabolic reflector antenna from specified physical dimensions. This spreadsheet, contributed by Edward R. Cole, estimates the gain of a parabolic antenna, taking into account aperture blockage by the feedhorn and its support arms. Assumes simple shadowing, and doesn't take into consideration diffraction effects. It assumes a circular feed structure and straight support arms from the edge of the dish.
Short helices make attractive dish feeds, and long helices are good high-gain antennas.
An elegant tool for quantifying our ignorance, the Drake Equation was developed by SETI pioneer Dr. Frank D. Drake as the agenda for the first modern SETI meeting in 1961. Its factors encompass cosmology, planetology, biology, anthropology, sociology, technology and psychology. It also estimates the average distance between communicative civilizations in the Milky Way galaxy. Converts between voltage gain, power gain, and dB. Assumes matched impedances. All submitted material will be considered entered into the public domain.