There is a third figure of merit name for small receiving arrays that came out of Syracuse University Research Corporation in 1967. It was called SNIF for Signal to Noise Improvement Factor. A term apparently coined by the author, Dr Martin Fournier. His report uses this term to describe the SNIF based on directivity of electrically small multi-element systems. Personally I kind of favor this term as it self describes the improvement. However it is still subject to the downfalls of being based on noise from all directions. Lee K7TJR OR
>That's very true. Consider the K9AY. The RDF is about 7.7. Compare that to a 1 wavelength Beverage which is about 7.9 dB. The K9AY has a deep null in the 180 degree direction at the right elevation angle, but 45 degrees off that rear direction the signal is down only 10 dB. The RDF number is a W8JI creation and serves its purpose, while the DMF is an ON4UN creation and also has merit, but neither of these completely encompasses all the things you may need to know about a receiving antenna for your location. You have to use some common sense in >junction with these numbers. Jerry, K4SAV _______________________________________________ Topband reflector - topband@contesting.com