Topband: 160M EWE Problems

[John Kaufmann]

> 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