Tower and Carriage

You can click on photos to enlarge them.

The pullies of the sliding carriage:

6 pullies in a triangular shape mouted on a greased staintess steel axle.

2 meters high. It surrounds the tower.

The pullies have to be positioned and soldered perfectly to permit easy movement of the carriage on the tower without causing any mechancial resistance.

Testing the carriage:

Before everything is solderd, one has to be sure that the carriage rolls up and down through the whole length. After soldering also, some of the pieces may move a little(because of the expansion of the heat and the cold)

Mounting chassis rotor azimuth:

The azimuth motor will be mounted inside.

The carriage is fitted on the tower. The placing of the carriage is fairly easy because the tower is in the cranked down position. One can distinguish on top: the rotor cage with the plates where the pulley system will fastened.

Pullies:

The tower is in vertical position. The stainless steel cable is attached to the triple sheave block which is composed of three movable pullies on the carriage and three stationary pullies on the top of the tower.

Winch and motor:

A DC motor with a variable speed control drives the winch.

Two pulley ratios are installed.

Box with the speed electronic variator.

The first raising of the carriage:

Reduced motor speed is important. The carriage goes up with no problem.

The carriage at its highest postion:

For the first time, the carriage is on the top of the tower, 13 meters up.

Emotion follows and...satisfaction !! 

  Elevation and azimuth rotors

Elevation rotor: 

The full view of the assembly

The placement of the motor:

Placing the rotor on the horizontal beam.

After several tries, the rotor is able to swivel round the beam at 90°.

Azimuth rotor:

The full view of the assembly.

The azimuth remote control system:

The potentiometer (360°) is driven by 2 gables. (identical diameter) 
The gable on the axis is adjustable in rotation to facilitate regulating of the remote control 

The coupling:

The mechanical connection is made by a double chain, which allow for easy dismanteling.

  Antenna support

Mounting of the horizontal beam:

The horizontal beam is put on. At the end beam are 50mm aluminum bars.These bars will support the fiber glass element.

Reinforcement of the bars:

I reinforced the horizontal bars with other bars placed on the X support. During this phase of the construction, it was necessary to put on scaffolding and a tall ladder in order to work safely.

Fiber glass elements:

4 fiber glass elements are fastened on the ends of the horizontal bars.

A large Ladder:

I had to constuct this large ladder because the ends of the fiber glass elements are 7.5 meters above the ground.Furthemore, the antennas are 16 meters long at this same height. My ten year old daughter would like to climb the ladder: she does not suffer from vertigo!

   The construction and placement of the FLA25HV antenna

Drilling:

A drill is necessaire to drill the boom on a 90° angle.It is time consuming and it is better to make a gauge.(see below)

The gauge for drilling:

Solution: I made a gauge. It is a lot faster to drill the boom but you have to be careful with the 180 degrees angle when using the drill. Place the gauge on the mark and you are ready.

The 40mm boom:

The 16.50 meter boom is placed on the sawhorse and drilled. Now I start to put on the U brackets and the elements.

Placing the elements:

Placing the first elements. The perceding step using the drill is very important for good element alignment.

Placing the elements:

It is getting dark.

All the horizontal elements are in place.

Dipole:

The coaxial cable is welded directly on the 2 elements copper of the dipole.

Installation of the first antenna:

My son Nicolas gives me a serious helping hand to bring up this first antenna. There are only at present the horizontal elements

The rope assembly of the antenna: 

The horizontal assembly with rope in dacron (red and black).
The different tests in TX can begin. The results are good enough, but it remains me again to " to sharpen " the impedance, the SWR of the antenna while displacing the 1st director very easily.

 First antenna OK:

The antenna functions perfectly.

The temptation to take the microphone is great. QSO,s begin with very good reports

The horizontal antenna adjusted perfectly, I achieve the installation of the vertical elements. These elements are baffled of 1/4 wave at the rear of the boom for easier installation.

Vertical rigidity of the boom:

2 tubes in fiberglass are added on the upper part to permit the tension of the rope in dacron. 2 stretchers are placed to the center of the boom + 1 to the rear.

Arm of lifting:

Arm of lifting with pulley in tip to raise the antenna.

It is necessary to have 3 people at minimum to bring up the antenna. Some moments before the photo, my son was on the scaffolding, YL maintained the rope of the lifting arm and me I was on ladder. That day, it was necessary so possible, not wind!

Ouf...! the antenna is finally put up after some working hours.

Not easy !!

This is not the place to be a clown!

2 antennas: 

The experience of the first antenna, makes easier to put on the second one. That day, no problems with Murphy's law!

4 antennas:

A few days later, the 4 yagis are put on, and I try out the site motion for the first time.

Rear access: 

While moving the elevation of antennas and the height of the carriage, it is easy ta reach the important parts of antennas.

The polarisation coaxial switch relay:

The coax switch relay is fastened on the rear part of the boom. 

Antennas at the top !!!

Couplings are finished, everything runs well...! do the first mechanical tests with the antennas: maximum height of the carriage, site and azimuth rotations, all works well. 

A few stress! quickly a photo ! 

   Weather report...the first week

Murphy's law weather:

During the first week of November 2000, antennas hardly raised, we suffer two strong storms. First resistance tests to gusts of wind (100 km/h)... the antenna holds weel. Again a lot of stress! 

The rear of the aerial, high and low parts, are fastened to the ground, ditto for the two lower antennas (rear and front of the boom). For the highers, we will see ...

   Workroom

Tools:

For all machinings, pulleys, axes, diabolo, lifting arm, etc, I am using a metal wheel. It is fantastic, how it's possible to make  easily many parts with this  wonderfull tool.

 Another tool is required : weld equipement with a split power supply. It only weighs 3 kg and it is very light and easy when you have to solder from the top of the ladder. As for the rest, the classic tools are used: drill, file, sander ...

N.B:   If you have problems to make the mechenical pieces, contact me. We will surely find a solution.

Finished for the moment !