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new
45G tower page
Rotating Tower
page
Lightning
Station Grounds and
grounding
Contesting and
Boatanchor Room
Antenna System and
my house station
This
page will show the
progress of the new
Rohn 65G tower. It
is now fully erected
right next to an
existing
lighter-duty tower,
and nearly all
antennas have been
transferred to the
new tower.
We
mounted the
erecting fixture
show below at the
top of the existing
tower so we did not
need to move the
pole up as we built
the tower. Now that the
new tower is built
we are
removing the old
tower. The old
tower’s guy lines
will be used on a
new Rohn 55G
320-foot tall tower.
Two
curtain antennas,
one for 80 and 40
and the other for
twenty through ten
meters will be
installed. I’m
reasonably sure we
have the highest
gain antennas on
Europe of anyone in
the USA. The 80/40
meter array will be
9 half-waves in
phase on 80 and 18
half-waves in phase
on 40 with a screen
reflector. The upper
elements will be at
300 feet.
This
is a very high gain
antenna. With 1500
watts applied,
effective radiated
power towards Europe
will be over 35
kilowatts to a
dipole at 150-feet
on 40 meters. We
anticipate having
the antenna
installed by fall of
2009. See how it
compares to a
Rhombic at this link.
Homebrew
Gin Pole Erection
Fixture for Rohn 65G
Pole
is 3 inch OD 6061-T6
with 1/4 inch thick
wall.
Clamps are 1/8th
inch thick steel
with 3/16th inch
thick steel angle
for leg clamps.
“T”
bolts allow quick
disconnect for
moving the pole.
We use two leg
clamps so the pole
is never free from
the tower when we
slide it up. Any one
clamp can easily
hold the pole.
The
clamp grabs the pole
with a compression
sleeve that is
knurled inside for
extra friction.
The
rooster head swivels
so we can lift the
tower away from the
face and then swing
it in to mate to the
tower.
Rohn 65G Tower Guy
Anchors and Base
The guy anchors are
heavy back-to-back
1/4 inch thick 4
inch steel channel.
The plate is 5/8th
inch thick steel.
The anchors are
eight feet long.
They end 5 feet
under ground
into a buried
concrete dead man
anchor with thick
rebar. The concrete
is three feet high
and feet wide for
surface area that
pulls against the
soil. The Akita mix
dog is named
Hershey. He only
weighs 100
pounds…and he
hasn’t bitten anyone
yet today.
This is the base
pier. The pad is 6-inch thick high
strength concrete
with fiberglass
filler. There is a
rebar grid embedded
in the pad with
vertical rebar down
into the center
hole. The ground
system ties to the
number six wire
surrounding the
base. Radials come
off the buss wire.
They are silver
soldered to the buss
wire. Four 3 inch
wide flashings will
connect the number
six wire to the new
tower base. There is
a wire grid under
the stones to
prevent voltage
gradient in the soil
under the repeater
shed.
This 7/8th inch
hardened steel pier
pin is all that keeps
the base from
kicking out. The
flat tower base just sits directly on the
pier.
This is the base
section. It is 10
feet tall, unlike
the other 20 foot
sections. Tall
towers are designed
this way so all the
weight is always
evenly distributed
on every leg, and so
the base can turn or
rock if twisting or
rocking stresses
ever get high. This
tower will hold an
80-40 meter
Distributed Feed
Curtain Array
aimed at Europe,
a 20-10 meter
Curtain for Europe,
as well as multiple
stacked Yagis for 40
through 10 meters
that are pointed
towards Asia and two
dipoles for 160
meters at 300 feet.
This is the bottom
section of the 65G
in place. It just
sits on the pad with
a pin sticking up
through a hole.
Bottom of tower.
Note the old phasing
box just above the
hut for phasing two
160 meter inverted
vee dipoles at 300
feet!
Tower going up. Now
at 60 feet.
200-foot 160-meter
and Europe 20-10
meter stacks tower
in background.
No antennas up yet
in this photo.
Going up. When the
new 65G is up, it
will be used to hold
the pulleys for
lowering the
existing tower.
Lifting a 300 pound
20 foot long
section. Now at 60
feet just passing
first guyline. Note
how tag line is
installed. This is
so we can maneuver
the tower and
control the tilt as
it is being raised.
Bolts are in the bag
clipped to the leg.
Passing the 80 meter
antennas at 150
feet.
Rohn 65G at 280
feet.
Below, looking
approximately 400
feet towards the
completed Rohn 65G
tower
with six point
guying at the top.
In the foreground is
a new Rohn 55G
tower.
This
320-foot Rohn 55G
tower will hold
the SE end of the
curtain array. In
the distance is the
315-foot tall 65G
that will support the NW
end of the curtain array.
as of page start on
April 20, 2008
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