From karinann at tampabay.rr.com Tue Nov 1 12:41:30 2016
From: karinann at tampabay.rr.com (Karin Johnson)
Date: Tue, 1 Nov 2016 12:41:30 -0400
Subject: [Antennaware] Phased Verticals
Message-ID: <799BE845465544A88360F80E57870EEE@karinspc>
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
From karinann at tampabay.rr.com Tue Nov 1 14:56:29 2016
From: karinann at tampabay.rr.com (Karin Johnson)
Date: Tue, 1 Nov 2016 14:56:29 -0400
Subject: [Antennaware] Phased Verticals
In-Reply-To: <20161101133452.Horde.XxwSaDRpuJWpWiG0pGJpvtb@webmail.hiwaay.net>
References: <799BE845465544A88360F80E57870EEE@karinspc>
<20161101133452.Horde.XxwSaDRpuJWpWiG0pGJpvtb@webmail.hiwaay.net>
Message-ID:
Hi Don:
At this point I am not trying to equate simulation with real world
performance. Since I am not in the actual building phase just yet, the
Only thing I am trying to accomplish is to understand some of the tradeoffs
In the design of the phasors and matching network. Especially being able
To switch directions without a totally complicated set of matching networks.
The complex math and physics I can handle. It is the actual implementation
in a simulated world
For now that I am trying to address. I know that there will be a lot of
variables when I get to the actual site build. Luckily, or not, I do have
The required test equipment and patients to accomplish the required
engineering to get the array working.
Karin K3UU
-----Original Message-----
From: donroden at hiwaay.net [mailto:donroden at hiwaay.net]
Sent: Tuesday, November 01, 2016 2:35 PM
To: Karin Johnson
Subject: Re: [Antennaware] Phased Verticals
Welcome to the world of "Antenna Snake-Oil".
I have been in AM Broadcast radio for 40 years, and I was always
fortunate to have had a large budget for installing 120 full length
radials and 120 half-sized radials and usually in great soil
conductivity like swamps and wet bogs.
Even then, the formulas only came " close ".
So, without a flat piece of copper out to several wavelengths, real
world values will float around as the seasons change
Don W4DNR
Quoting Karin Johnson :
> 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
>
> _______________________________________________
> Antennaware mailing list
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