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To: K4PI <>
From: Roger D Johnson <>
Date: Tue, 03 Jan 2006 12:10:20 -0500
List-post: <>
K4PI wrote:
> I need some opinions on a direction to go with an array I have built.  It is
> a 4 square for 160 M using 90  ft vertical T's with 45 ft top hats supported
> by a center 140 ft tower.  At present it is being fed by phasing lines
> through a borrowed Comtek box.  My original plan was to buy the DX
> Engineering phasing box once they get it to market but after studying the 5
> element array on page 13-31 of Low Band DXing, 4 the edition I am now
> questioning that decision.  K3LR is the one that used the array on 160
> whereby he feeds the center tower only and uses the other verticals as
> directors or reflectors plus an omni selection by floating all the elements.
> Each vertical is changed from reflector to director by means of a relay and
> a loading coil.  The big question is whether to proceed with the DX Eng
> driven system which give 8 directions plus omni or going with the parasitic?
> By the time it is all said and done probably price is not a factor as I have
> already laid the phasing lines out .  The price on the parasitic would be
> the cost of the relays, boxes, inductors, omega match caps for center tower
> and all the control line cable plus the time of tuning them.  The driven
> system would just be buying the phasing box and hooking it up as the
> vertical are all tuned.  Any comments?
> 73 Mike K4PI
> _______________________________________________
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One thing that doesn't seem to be considered when planning this type
of array is the ground loss resistance. This appears in series with
the element and may prevent enough current flow to enable the element
to act as a parasitic. In a driven array, with a properly designed
feed system, the elements are "forced" to carry the proper currents.
So, if you're planning a parasitic array, plan on installing a good
ground system also.

73, Roger

Remember the USS Liberty (AGTR-5)

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