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[Antennaware] Phased Verticals

To: <antennaware@contesting.com>
Subject: [Antennaware] Phased Verticals
From: "Karin Johnson" <karinann@tampabay.rr.com>
Date: Tue, 1 Nov 2016 12:41:30 -0400
List-post: <antennaware@contesting.com">mailto:antennaware@contesting.com>
Well some progress has been made.  I've ordered Low Band DXing to obtain the


Complete software CD so I can be a bit more efficient in my modeling
efforts.

I did complete my own spreadsheet to compute the mutual and driving point 

Impedances for a two element setup.  I agrees with some of the ON4UN 

Spreadsheets that someone else has sent to me.  So in my own mind I am
getting

To feel comfortable with understanding some of the physics behind phased

Vertical systems.   I do have advanced degrees in Math and Engineering so 

I'm no novice to complex numbers and issues around designing matching
networks.

The esoteric things like inductive and capacitive voltage dividers used in
Phasor

Networks is starting to make some sense now.  

What sort of has me baffled a bit is that looking at what Array Solutions
has

Available for a triangle array Phasor, doesn't seem to take into account the

Large difference in driving point impedances when switching directions.  The


Array Solutions triangle box only works for 50 ohm loads at each port to
guarantee

the phases required at each antenna port.  In other words it only does the
phasor

portion of the antenna system, not the complex impedance matching required
at

each antenna.  The matching networks required at each antenna will
contribute

a phase shift of the driving current.

For example for a triangle array of three 40M verticals spaced 0.29
wavelengths,

The driving point impedance calculated for direction 1 is:

EL1 = 60.16 + 12.29

EL2 = 16.42 - 43.29

EL3 = 16.42 - 43.29

Elements 2 and 3 are driven with a current magnitude of 0.5 angle of +90,
Element

1 is driven with a current magnitude of 1 angle of 0.  The far field plot is
in the 

Direction (or off the end) of the Element 1 direction.  Elements 2 and 3 are
behind 

Element 1.

If one were to switch directions and there were matching networks at the
base of 

Each vertical the complete matching network would have to be changed.

I can't seem to get my head around a solution just yet.  More research on my
part

Is certainly required.  

This is a fun project for me so far.  

Eventually some time early next year I like to get started building this
array.

I know what most folks might say just put it up and have fun but I'm the
type

Of person to know the physics and math behind what works and what doesn't
work.

 

Regards,

 

Karin    K3UU

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