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W8JI map:
Each arrow indicates an antenna, with the arrow heads indicating
directions. When multiple arrows are parallel, the antenna is an array of all
antennas. For example, if you look southeast of the 8 circle vertical (160M),
you will see three arrows going NE and SW. This array is three 880-ft Beverages
about 330 feet apart, fed broadside with a 1:2:1 current ratio for minimal side
lobes. Also shown above are towers, with number designations for height except
160 TX, which is a ~200 foot vertical for omni and four wire elements to form an
eight direction 4 square antenna, and ROT which is the ~200ft rotating tower.
Small verticals, and a 4 square for 40 meters, are not marked.
Receiving Antenna Arrays
Conventional
Beverage’s ~580 feet
long. Currently only two left, reversible, far in the rear. They can be used for
higher bands, reference comparisons, or for spotting purposes. Maintenance
of the conventional antennas is somewhat erratic, since they are rarely used.
Specifications @
15 degree wave
angle:
N, S, E, or W patterns.
Directivity 7.29 dB, half-power
beamwidth ~78-degrees
Arrays of
Broadside Beverages
780-880 feet by 350 feet broadside spacing.
Currently two similar systems
spaced ~1000 feet
apart, with antennas
E, SE, S, SW, W,
and NW (28
individual Beverages
make up this
system).
Specifications @
15 degree wave
angle:
Directivity
factor 13.8 dB,
half-power beamwidth
42-degrees
For NE, a primary contest direction, the rear Beverage is three 880-foot
Beverages spaced 300-feet between antennas, combined in a 1:2:1 current
distribution. The front Beverage is two Beverages 880-feet long and 350 feet
broadside, combined. A secondary single Beverage 800-feet long is on Europe for
80 meters and higher. Distance from rear Beverage to front Beverage is somewhere
around 1/2 mile, allowing for spatial diversity in stereo.
Front Beverage pattern at 15 degrees:
Directivity 13.8 dB HPBW 43-degrees
Rear Beverage three-antenna pattern, shown at 15 degrees
arrival elevation angle:
Directivity 15 dB
Arrays of
small Verticals, 70 by 330
feet. One system:
Specifications @
15 degree wave
angle:
Reversible for ZL/South Pacific,
default on Europe.
Directivity
13 dB,
half-power beamwidth
47 degrees
350-foot
diameter circular
eight-element array.
One system:
This array covers
eight directions,
spaced every 45
degrees around the
compass. It has
22-foot tall top and
base loaded
elements. Over 1/4
mile of 75-ohm cable
is used in this
array (and 2500 feet
of cable to reach
the
house).
Each antenna
element is made from
1-1/2 inch chain
link fence top rail.
The fence rail
hinges on these
wooden posts with a
bolt through the
bottom of the
vertical rail. The
top of the wooden
post has a steel pin
that fits in a hole
in the metal
railing, and it is
lashed in place.
Specifications @
15 degree wave
angle:
All compass
directions.
Electrically
rotatable.
Directivity
factor 12.1 dB,
Half-power Beamwidth
53 degrees
Selection Matrix System and Amplifiers
I use one central entrance point, located in the house, for all receiving
cables. This is the single point where all equipment and cables inside the house
ground. Unless required for power or electrical safety, there are no grounds to
equipment on my desk.
This is my “wire hider” box. All amplification is in the house. Amplification
outside actually decreases dynamic range.
There are three permanent direction
antennas, all northeast for Europe, available at any time, regardless of any
other antenna being used.
Note that all antennas enter the matrix through connectors mounted on the
copper wall of the receiver switching system. This forms the common ground
point. Further, you will see the outside entrance common grounding point, just
on the outside of the wall behind my “wire hider” box.
Antenna Group and Audio Selection, House station
This is similar to my Contest Barn setups. The two right side switches select
the audio input and ear for headphones. Any ear can be placed on any receiver.
The balance control sums L and R audio to a mono speaker amplifier.
The two left-side rotary switches chose the array group desired, while the
silver box on the table picks direction of that group.
Outside Entrance
This house entrance is common grounded to the inside shack common ground
point. This is a double-barrier single-ground system.
This is also a test point, where terminations are applied to replace external
feed lines, for in-shack noise.
My equipment is dead quiet with terminations at this point.
Beverages
Contest Barn
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