Rohn 65G Project
new 45G tower page
Rotating Tower page
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