[BC] Ground system

[Cowboy]

On Sunday 12 February 2012 03:15:30 pm Phil Alexander wrote:
> He
> told me that 9 deg. was a first experimental approximation that 
> worked so well he felt there was no point in trying other heights.

 That's unfortunate.
 It means that we have no empirical evidence that any other
 height would be better, or worse, or what the compensating
 factors might be.

 It leaves unanswered, if 120 reaches some 9? % of ideal when
 laid on the ground, how many would be equivalent at, say, 3 feet
 above ground, or 6 feet, or 10 feet, and is the portion of
 a wavelength important ?

 In essence, all he really provided was a proof of concept, which
 was already provided by the ground plane designs for VHF that
 predate the experiment.

 What's unfortunate, is that a proof of concept is accepted as
 a standard, such as the 120 radial standard, when it may be
 that small changes make a larger than anticipated difference,
 or that a large change makes a smaller than anticipated difference.
 Say, 60 radials instead of 120.

 Perhaps, if the elevated feed and elevated radials were taken to
 say, 25 or 30 degrees, that the traditional droopy drawers
 three radial arrangement would turn out to be optimum ?

 We know from VHF three radial droopy drawers that at or above
 7 wavelengths above ground, ground reflections become
 negligible, but do we really know much, if any, more ?

 Unfortunately, we know how to make it work the way it's always
 been done, merely because that's the way it's always been done.

 I would argue we have insufficient data. 
 Maybe it's just me ?


-- 
Cowboy