Topband: 8 circle: DXE vs Hi-Z

[Greg Zenger]

This thread comes at a good time for me, as I am planning an 8 circle array
as we speak.

My installation will be an 84' diameter circle as I intend to us it on both
160 and 80m.  My installation will be in the woods on a rocky hill (New
England glacial moraine). I have found a plateau near the top of the hill
where I can install the elements with all feed points at the same height.
There is no area where I could put a larger spaced array at this location,
and I am willing to trade-off some performance on 160 for coverage of 80m
as well.

I plan to go with the DXE kit, as i have been impressed with DXE products
in the past.

While reviewing the manual for the active receive antennas, I found that
DXE recommends four to twelve radials at least 15 feet long, but no longer
than 20 ft.  I plan to deploy radials around each element due to the rocky
area this array will be installed over, so I know radials will be required.

My question is why the cutoff at 20'?

Another question is would I benefit from a taller vertical element than the
 8.5' whip included with the kit?


73 Greg N2GZ



On Tue, Dec 16, 2014 at 9:35 AM, Joel Harrison <w5zn at w5zn.org> wrote:
>
> Greetings Bob & Reflector folks,
>
> Please allow me to provide a bit of my experience since I run both a broad
> side/end fire passive 8 vertical array (350 ft diameter) with a DXE
> controller AND a HiZ 8 vertical array spaced for 160 meters (220 ft
> diameter).
>
> To your specific question about controllers both will perform very well
> but there are differences in the arrays that need to be considered, so
> please allow me a bit of bandwidth here to explain.
>
> I installed my BSEF array about five years ago when there was practically
> no avalable information about the array and no commercially available
> controllers. I built the array and a controller and published my work in a
> paper on my website that later was published in QEX.
>
> Since that time, I have gained a great deal of experience with the array
> both mechanically and eletrically and as a result of my published work
> others have built arrays (w3LPL for one) had have shared their valuable
> experience publically as well. As a result, I rebuilt my BSEF 8 vertical
> array this  year with a different mounting scheme like W3LPL uses and also
> moved to a better controller that Mike, W9RE first made boards available
> for and now that DX Engineering sells, which I now use for control of the
> BSEF array.
>
> Over this time Lee's HiZ arrays have become quite popular and are
> excellent performers. What I have noticed is there is considerable
> confusion among the masses about the differences in these arrays and to be
> quite blunt many folks equate living in an excellent geographical location
> for 160 meters propagation to amazing performance of a specific RX array
> which is an error. I am obsessed with 160 meter RX antennas and achieving
> peak performance from my rural location in central Arkansas, an area that
> is not enhanced by coastal propagation, etc. So I set out last year with a
> personal mission to evaluate both 8 vertical array systems, the passive
> BSEF array an the HiZ. I am not in the amateur radio business, I'm just a
> ham with a desire to have the best 160 meter RX system possible for my
> geographical area.
>
> So, both systems are operational here. There is significant sepeation
> between the two arrays (>800 ft) and both are a significant distance from
> the transmit antenna. Both have their own level of complexity with
> installation and from personal experience I can tell you they each take
> about the same amount of time to construct and install.
>
> I have already recorded several real on the air comparisons of patterns,
> noise floors (taking in to account one is active and one is passive)and
> several signal comparisons of DX stations (actual signal level about noise
> floor, not S meter readings). I plan to publish these results in early
> spring at the end of the 160 meter DX season for north america.
>
> I would be more than pleased to discuss any specific questions you may
> have about these arrays off line a bit more in detail if you would like
> but again the short answer to your question is both will be excellent
> arrays.
>
> 73 Joel W5ZN
>
> > I'm new to 160 and am planning to add an 8-circle. I would like to buy
> > commercial preamps and the controller. I would greatly appreciate any
> > advice on the choice of preamp/controller vendor.
> >
> > I live in a rural area and have a 4-direction 3-ele vertical array for
> > 160 with a 20+ dB f/b. So I'm looking for a beamwidth improvement on
> > receive.  Here are a couple questions:
> >
> > - Are the functions of the control network the same or similar between
> > DXE and Hi-Z? (so I could use either one?)
> >
> > - DXE wants a 320' diameter and Hi-Z wants 200' for optimum performance.
> > It's hard to tell what DXE performance is because it does not disclose
> > RDF, beam width or F/B. And neither vendor supplies EZNEC files so I can
> > see the effect of varying the layout. So I'm not sure how to decide what
> > array size is best for me. It would be wonderful if someone has a model
> > for these two systems.
> >
> > - If I use DXE, is it a no-brainer to use 24' verticals instead of the
> > shorter supplied whips?
> >
> > - are there any best practices for weatherproofing the Hi-Z components?
> >
> > - are there any build-quality differences between the two that I should
> > consider? I live in MT, so it is a harsh environment.
> >
> > Thanks!
> >
> > Bob, N7IP
> > _________________
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> >
>
>
> www.w5zn.org
>
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