SARK 's biggest project ever

Here we will present the work of putting up our 4 x 2M8WLHD from M2 . These antennas are the best you can find right now. They chose to put up four antennas instead of 8 as we had been forced to take in order not to change us down from the previous antenna set of 4 x 17.


The antennas we are setting up is 4x 2M8WLHD which is 16.5 m with a stacking distance of 6m and this means that we took the opportunity to upgrade the current rotor at a PST71 Prosistel with associated Control Box D. We were greatly surprised when we got the rotor and full of expectation would test drive ramp at start & stop . This important function is the more important for large antenna arrays !

Prosistel can not build motor controls !

Per 6the , Bengt Section leader 6TOB and Jan 6GOR was equally surprised by how rotor ramp was up / down speed. The way Prosistel have resolved the matter on we would not consider to be that soft start a motor . Soft start was that through about 5 different voltage increases to increase the output voltage of about 12V - 24V .

Next 'wrong' is that the designer is the worst kind of tricksters . Obsolete technology and complete ignorance of the programming and operation of the microcontroller . The motor control system comprises two relays and a possible FET for controlling the motor . In my and everyone else's other world amvänds an H-Bridge and PWM function in the controller. PIC circuit in the box is a PIC18F458 and it has a built-in PWM function that I believe used . It can be easily generated voltages from 0V - 30V in steps of about 0.25 V. Next was to start / stop not working when the rotor was run manually or if the rotor emergency stop was with the buttons. Prosistels solution to stop was to cross rivet engine!

Here we present the solution to the problem.


A failure to we have not mentioned is that the color of the rotor flaking very very easy. Painting is a must!

More than we have a problem with the rotor. One tip we have is to replace the 10 -turn pot in the rotor of a 3 -way . We will make the change as soon as the weather allows.


- 13/3-10 top section into place

- 21/3-10 rotor assembled and tested

- 27 & 28/3-10 Assembly of antennas begins

- 4/4-10 The last element is locked . Assembly of elevation begin and HF mast inspected

- 10/4-11 Pupils No fitted to the mast

- 16/4-11 Div. purchase before the work day is done . Drainage of trusses and the assembly of the truss to the mast .

- 20/4-11 Coax hijacked and contacted with the utmost care. Mounting of the first antennas commences. Guy lines are cut .

- 21/4-11 Continued installation of antennas and guy lines . Trimming the antenna proves hard and help boost ' over there ' begins.

- 22/4-11 project biggest slip hitherto been detected ! Remedy start immediately ! Antenna 1 is mounted in H: et .

- 24/4-11 project is progressing with new ideas and antenna 2 is mounted in H ' !


-28/8-12 Interesting discussion on Prosistelrotorn Starter IW4BLG Pigi on an Italian forum ( Google Translated) . Another question that can be asked is how many days a year ;-)

For techies are PST -61 exploded .


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