You may want to consider parasitic feed. That could simplify phasing a
bunch.
And you may find that vertical dipoles are quicker to deploy (depending on
the frequency)
de Paul, W8AEF
----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
To: "Dino Darling" <dino@k6rix.com>
Cc: <towertalk@contesting.com>
Sent: Tuesday, June 27, 2006 7:52 PM
Subject: Re: [TowerTalk] Portable Phased Arrays!
> At 07:08 PM 6/27/2006, Dino Darling wrote:
>>New thread; lets hear about the portable phased arrays Jim!
>
>
> Still in the tinkering stage.
>
> Design criteria:
> From wheels stop to fully deployed and on the air in <20 minutes. This is
> a pretty challenging constraint, in itself.. No fiddling with hose clamps,
> for instance. It gives you about 3-4 minutes to put up each element, and
> another 5 minutes to hook it up and run the calibration.
>
> Basic concept:
> Simple vertical antennas (trapped or not.. I'm still doing experiments on
> that, there's some interesting vertical angle tradeoffs between a trapped
> vertical and a plain non-resonant vertical with a suitable matching
> network), arranged in an arbitrary array.
> {you might be in a roadside parking lot.. you just have to take what you
> can get}
> Array calibration (determining mutual Zs and relative positions of
> elements) in-situ
> {relays to connect cal signals to each element in turn, listening on the
> other elements, etc.}
> Computer controlled phasing networks to do the phasing.
>
> Primarily the phasing approach is for transmit. On receive, I think you
> can do better with suitable E-field probes, separate receivers, and lots
> of
> DSP.
>
> It's not going to be a 4 element SteppIR at 100 ft, but it should be
> interesting. And, once it works for this, it's generically extendable to
> all sorts of other applications.
>
>
> Jim, W6RMK
>
>
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