> A reversible array is far and away the best way to convince yourself > that you have a working receive antenna system. If you reverse it and > nothing ever changes, well, you're listening to some other antenna! > Some (e.g. YCCC array) are supposed to be far more sensitive to near-field
> metal objects than others (e.g. K9AY loop) but even then I'm sure you'll be > able to find a convincing F/B on known BCB stations once you have stuff working right. The YCCC array and other high-performance receiving arrays have much higher directivity, and correspondingly higher RDF's, than a K9AY loop. On 160m, the YCCC array has an RDF of 12.1 dB while the K9AY loop is 7.7 dB. This is not a criticism of the K9AY loop because it is a very simple yet effective solution for many people. However, it is a fact of life that achieving higher directivity in multi-element arrays necessarily means more careful control of the amplitudes and phases of multiple elements. A corollary of that is small perturbations introduced by external influences, like metal objects, can degrade directivity rather easily. There is no free lunch. 73, John W1FV _________________ Topband Reflector Archives - http://www.contesting.com/_topband
