"Buck" wrote in message
...
On Fri, 04 Mar 2005 05:41:29 GMT, "
wrote:

I have just come to realise that if one drew a polygon of element phases
in
a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the SAME
frequency!
Until now I was of the understanding that these two max figures could not
occur at
the same frequency. Is there anything written about this possibility?
Regards
Art



Art,

Your description is too vague for someone who doesn't have some form
of reference (maybe this is a continuation of a discussion from
elsewhere?) Anyway, since a polygon is any shape with more than two
sides in which all sides and angles are equal,


It does! then I have used the incorrect term.

In a yagi type diagram you can calculate the current and phase of each
elemrnt
but what one is interested in is the summation of the whole array and you
can do this
in the same way as you would do a vector diagram of forces.
With the yagi array you would first start with the reflector and draw to
scale a line
reflecting both phase angle and magnitude. You then add lines in cosecutive
order for all other elements in the array. The end of this 'toe to tail'
some what
erratic line will finish up some distance from the starting point,
but this distance, if drawn, represents the phase and magnitude
of the array as a whole. As a former mechanical engineer
but now nothing ,I was taught the term "polygon of forces" which is a
cumulative
vector array but the shape did not necessarily consist of "equal "sides as
you stated..
But then I am English born and it is known that Americans completely messed
up the Elizabethan era language which a true cockney still adheres to ,
where as
others in the same country have learned to talk in such a way it sounds as
if they
are trying to retain a marble in their mouth.without swallowing it.
Regards
Art


this leaves a rather
wide variety of shapes. Is this referencing vertical or horizontal
elements? With the 180 degree element comparisons, I assume you are
dealing with an equal number of sides on each polygon, or in case of
verticals, at least an equal number of elements..


Is there any more you can tell us?


--
73 for now
Buck
N4PGW