----- Original Message -----
From: "Paul Kelley N1BUG" <paul.kelley.n1bug@gmail.com>
>. However, the lower gain in the reverse
> direction is not a serious problem as long as the pattern remains
> acceptable.
>
> Front-to-back ratio has a tendency to be very good in the "reverse"
> direction but not as good in the forward direction. A poor ground at
> the far (non-feed) end seems to make this worse but even with good
> to excellent grounds I still notice some difference in F/B between
> the two directions. This may be unique to my particular
> installation. ....
> may result in a different pattern for the two directions. Other
> theories include imbalance in the reflection transformers or the
> Beverage itself. I am very interested in the experience of others
> with regard to F/B of WD-1A reversible Beverages.
>
There have been some discouraging reports about signal attenuation of a
WD-1A two wire Beverage used in the reverse mode. Prior to these reports
surfacing, I had ordered a mile of WD1-A and a few weeks ago ordered the
KD9SV transformers for this wire. Even expecting the worse I decided to try
anyway to see for myself if the reverse mode attenuation reports are as bad
as claimed. (Reverse mode reception of NW and NE is my only good option
since the open field lays to the south of my QTH with the ocean or a large
salt pond on the far side of this field.
Setup: I have now two 2-wire 600 foot Beverages running (toward) SW and
about 65 feet apart. Both run in an essentially unobstructed former hay
field now covered with brush and small trees
Beverage #1 uses 450 ohm #16 solid conductor ladderline and is
fed with RG-6
and terminated with DX-Engineering's RBS-1 two coax feed unit and
reflection transformer.
The antenna is 4 to 5 feet average ABG. The reverse direction is
NE toward Europe
Beverage #2 uses WD-1A narrow spaced military field phone wire
fed with dual
RG-6 cables and uses the KD9SV transformer boxes designed for
this wire. Both
boxes have two ground rods and (3) 30 foot spiders.The reverse
direction is NE.
Test Procedure:
During the CQ WW Contest this past weekend I was able to do A/B
switching on over a
100 European stations concentrating mostly on Eastern Europe
stations and beyond in
Asiatic Russian and the Eastern Mediterranean areas. The
switching was with a
Waters"Protax" coax switch.
Test Results:
Never was Beverage #2 inferior to Beverage #1...not once! Both
were equal and even the
weakest signal on either Beverage was equal to the other. Since
the forward direction
(SW) is limited to a few stations in VK and ZL I was only able
to check the forward
direction with 2 stations ZL3IX (morning before the contest) and
VK3ZL the morning
after. (I sure wanted them during the contest but neither was
heard) VK/ZL is the
forward direction and again their was no discernable difference
in performance of either
antenna at this location.
Summary: DX-Engineering makes superb antenna accessories but the KD9SV and
WD-1A field phone wire combo are adequate and less costly to construct.
Other issues include the longevity of the wire itself of which only time
will tell. The WD-1A wire wins in the aesthetics department as the
ladderline is very visible. The WD-1A does not allow internal single coax
switching like the DXE unit. Both manufacturers stress the unused port must
be terminated in 75 ohms. I have tried to test this requirement but so far
have not found that on the shack end makes any difference, i.e. open,
ground, or terminated in 75 ohms.
I know this is not a very scientific test but it is what I have observed in
testing this two fine units over the last week. Next goal will be to try
and phase them with my MFJ-1026 to see if there is any pattern or null
shifting possible. In theory two parallel 600 foot Beverages even 65 feet
apart should allow some additional enhancement if fed properly.
Let me know what you think
73
Herb, KV4FZ
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|