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[IRCA] Beverage - Wellbrook Array Comparisons
At 18:22 11/8/2009, Chuck Hutton wrote:
Nick Hall-Patch had his ALA-100 array at Grayland with myself and
Bruce Portzer Oct. 3 and 4. During that period, we compared it with a
1400' Beverage at 320 degrees that was terminated via 3 six foot
ground rods. A different antenna than a 600' Beverage, to be sure.
It was no contest at all according to Nick. The Beverage was in a
league by itself. Perhaps Nick can provide details if needed.
The Beverage provided Chinese adio on at least 111 channels, and
there are some recordings still in the can that I have not checked.
Chuck
At 6:22AM 11/9 Nick Hall Patch wrote:
I might want to temper what Chuck has said, seeing that I am "on the
record" now .
First, the Wellbrook array could hear some things better than the big
Beverage could. For example, no KFBK-1530 on the array at all except
in reverse position. 1530 was effectively an Asian channel on the
array, and I could hear Japanese trading places that were just
garbage fighting under what was left of KFBK on the Beverage. A
phased pair of Beverages would possibly (likely?) have levelled that
playing field.
If there was a distinct source of interference off the back end, the
Wellbrook could deliver a better signal to splatter ratio. This did
not always mean a better quality of DX however, because, sorry guys,
size matters, at least in the antenna world; I won't venture into
other worlds, but I'm sure the contents of your junk folder will tell
you all you need to know. I don't really know the technical reasons
for this, but it makes sense that a big antenna will deliver a more
robust signal than a smaller one will. In the demodulation process,
generally the more signal you have, especially in those AM sidebands,
the better the readability you will have, even if there is relatively
more interference as well (within limits). This is I believe the
source of the difference Chuck alludes to.
I've observed this locally, comparing a fine Flag antenna I have
versus a more haphazard corner fed loop which has about twice the
enclosed area. The Flag has observably better rejection off the back
end (thereby nulling all my domestic interference with varying
degrees of effectiveness), and is a quiet joy to listen with. But the
corner fed loop, relatively extra splatter and all, often delivers
more readable DX, as it is enclosing a larger portion of the incoming
wave fronts, and delivering more raw signal which is demodulated
better. It's crisper, less murky, i.e. more readable, and it looks
good on the S-meter too. (and yes, bulking up the Flag's signal with
a preamplifier to match the corner-fed's signal often doesn't seem to
be enough)
If it's a matter of real estate, the Wellbrook array wins every time
however. 50m worth of a straight line will get you a darned nice
antenna with, in this part of the world, rejection of pretty much all
of North America's signals, leaving you with a great starting place
to hear Asia and Oceania. 50m of wire will get you world class
splatter in the same location, no matter how well you match it to
your receiver. What is staggering about the Wellbrook array is that,
according to John Bryant, it is competitive with a 600m wire, which
is a Beverage antenna, at least above 1000kHz. With the price of
land, that's a serious advantage.
Having said all that, my feeling (and it is mostly a feeling) at this
point is that if you have the opportunity to use a man-sized Beverage
antenna, especially if you can enhance it with phasing as with Neil's
BOGs, then you will still likely hear better DX than with the smaller
and truly wonderful phased arrays. It's up to you to decide how many
more years you will wait until retirement in order to be able to
afford the land needed for a serious Beverage array at the seashore, hi.
best wishes,
Nick
John Bryant's response 9:00PM 11/9
There have been several good exchanges amongst several DXers relative
to antenna theory in general and comparing these two very different
antennas in particular which are not directly relevant to my own
remarks, so I have not reproduced them here.
As far as Chuck's allusions and Nick's clear report of the comparison
of his Wellbrook ALA-100 Array and Chuck's favorite 1400'
well-grounded Beverage, I think that subject is well covered, too.
What Chuck seems to ignore is that the Wellbrook family of Phased
Arrays has gone rather far beyond the unit that Nick A/Bed with
Chuck's Beverage: there are currently two new Arrays, both of which
have been A/Bed at Grayland and each of which represents a very
noticeable improvement over Nick's ALA-100 Array in the ability to
hear very weak DX signals from an ocean-side location. The results of
all of those A/B tests have been reported here; why does Chuck ignore them???
Over recent months, Wellbrook's family of non-resonant, large single
turn loops has expanded from one to three. These are my personal
observations of all three families:
ALA-100
This is the oldest of Wellbrook's large, single turn loops. It has
modest gain (about 10 dB) and is very forgiving as to size and
configuration. It is very quiet and exhibits a classic figure of
eight pattern. The ALA100 excellent and very popular antenna and its
operation is independent of grounding.
ALA-100 Phased Array
This is the original Wellbrook Phased Array and still offers a great
deal to many DXers. The basic phased array consists of two ALA-100
loops in 20 meter long Delta configurations(about 220 sq.ft. each)
separated by 40 meters. That basic ALA-100 Phased Array is
independent of ground, reversible at the throw of a switch, and quite
suitable for strong RF environments, due to its modest gain. Front to
back ratios of 30 dB are routine and 45 dB are achievable under ideal
circumstances. Due to the wide forward lobe, the two of these loops
in the basic array will cover the horizon in two unique RF views
(say, North and South). Four of these loops in two pairs would give
N, E, S, W views of the horizon, with all four loops sharing a single
array controller. However, the broad front lobe means that each view
is of 180 degrees of the horizon, though a different view for each of
the four selections. Strengths: four directions, switch selectable,
small foot print, no ground needed and works in strong RF
environments. Weaknesses: Forward lobe could be narrowed by 50%, gain
and F/B could be increased further.
This is the Wellbrook Phased array that I've used both for TP DXing
and domestic DXing for two years and I've loved it. It is also the
Array that Nick used in his fall 2009 A/B test with Chuck.
The New K9AY (Summer 2009)
This is a new "loop head" unit from Wellbrook in summer 2009. It runs
a Delta Loop of about 250 sqft. It is a higher gain antenna....
something like 18 dB and is (switch-selectable) bi-directional with
around 15 or 20 dB of F/B and a considerably narrower front lobe than
the ALA-100. Stand alone, it is a very interesting antenna,
especially the switch-selectable directional change. Its weakness in
some environments (like the seashore) is that it requires a good
electrical ground at the base of the antenna. In places like
Oklahoma, where grounding is not a problem, this may be an excellent
DX antenna. Due to the somewhat narrowed front lobe, stations to the
direct sides of the antenna may be attenuated.
The new K9AY Phased Array (Summer 2009)
It was simply a matter of time, I guess, until Andy Ikin of Wellbrook
began to phase two loops together that were already, themselves,
quite directional, thus double-dipping for truly FINE F/B
ratios. The K9AY Array was the first of these that I was able to try
out. Unfortunately, I was unable to provide adequate grounding either
at my home on Orcas Island (where it also overloaded badly) or at
Grayland. Andy designed a ground radial system for me that did
achieve at least 30 dB of F/B, still far short of the full F/B ratio
(and the signal to noise ratio) that this antenna can achieve. At
Grayland there was no sign of signal overload with this antenna. Even
operating at half-or-so efficiency, this antenna was a significant
improvement in S/N as well as raw forward gain to the ALA-100 Array
in multiple A/B tests over two DXpeditions in late September and in
mid-October. I really look forward to using this antenna in Oklahoma
next month, both DXing Mexicans and in just general domestic DXing.
With its very excellent gain, huge F/B ratios and relatively narrow
aperture, this ought to be an ideal domestic DXing antenna,
especially if using the full two-pair phased array.... as long as
decent grounding is achievable.
This is the antenna, in a two-loop configuration, that A/B tested as
being substantially an equal to the prototype of Dallas Lankford's
4-loop diamond array as built and run by Guy Atkins at the nearby
Grayland Beach State Park (mid-October DXpedition.)
The New FLG-100 (Summer 2009)
This is a new loop head and power supply that is configured to
support a multitude of single turn loop designs in the Flag, Pennant,
EWE and Super Loop family. Each of those designs expects about 900
(or in Wellbrook's case, a 1000 ohm termination, on the far end of
the loop.) For all DXers whose interests in DX lay in a single span
of directions.... at least in a given DXing session... this may well
be the antenna for you! Good forward gain, relatively narrow aperture
and not dependent on being grounded... The same loop head that runs a
well-grounded EWE at home could be taken to the beach and run a Super
Loop or a Pennant. The weakness of this highly directional antenna is
that the direction is not switch-selectable from the operator's position.
The New FLG-100 Phased Array (Summer 2009)
I actually set this up as a Wellbrook "Super Array" using two Conti
"Super Loops" as elements in the array. These were originally 17'x60'
Super Loop elements, spaced at 40 meters apart. That is over 2000
sq.ft. of phased loop in the air. I A/Bed it directly against the
then champion, the K9AY phased array. The Super Array was
significantly superior to the K9AY array when looking in this single
direction, but the gain and enclosed area were so large that my
rather hefty Winradio G313e was actually overloading on the stronger
Japanese stations. So, before the final night of the early November
DXpedition, I shortened the two phased Super Loops to half their
previous length: 17'x30' spaced at 45 meters. This antenna operated
VERY well and was still noticeably superior to the poorly grounded
K9AY Phased Array. Without question, this is the antenna that I will
use (most likely in its "Super Array" configuration) at sites like
Grayland, for the foreseeable future.
I really hope that Wellbrook foresees enough business to keep all
three loop heads and antennas in the line-up. Each has its place and
role, as an individual antenna as well as an element in a unique
Phased Array. For myself, I'd like to use the ALA-100 Array on Orcas
Island (modest gain, no ground, switchable); I'll use a Super Array
at Grayland (single direction, maximum F/B, S/N, no ground) and I'll
likely be using the K9AY 4-loop array in Oklahoma (great gain, great
F/B, S/N and switchable in four directions.)
So, what is the best antenna for seaside locations? If you can solve
the liability and ownership problems that abound along most coasts, a
well-grounded 1400 or 1500 foot long Beverage is likely the antenna
of choice. If your antenna possibilities are any less than that, at
all, then the less than 200' long Wellbrook Super Array is likely
VERY close to that long Beverage and clearly a major improvement over
the ALA-100 Array.
John Bryant
Orcas Island, WA, USA
Winradio G313e and various Ultralights
Wellbrook Phased Array + Superloops
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