The right height of radiolink antenna masts in telecommunication are connected with concept of so called Fresnel Zones.  Energy sent between radiolink antennas forms shape of a spindle (cigar like) with the biggest thickness in the midpoint between them. Points for antennas installation shall be found in the way that no obstacle gets into the Fresnel zone, otherwise the gain will be compromised (tree tops, houses, hill tops, or simply ground surface).

There are numerous online applets that let us calculate Fresnel zone thickness in given place between antennas. Having this information, plus maps and real terrain measurements let us find minimal mast/tower height that lets transmit all the energy between radiolink antennas.

Well in most cases stiff mast is a good mast, this is one of quality factors. Cheaply built masts are rarely stiff. Stiffness is mostly important for radiolink communication and satellite dishes (form of radiolink in fact) – where power beam is narrow and focused. Imagine a laser pointer that is aimed at a tower clock from outskirts of your city. Not easy to keep it steady pointed directly on the clock face… but fix it to the building and the beam will be glued to the point miles away.

In most countries masts are created to allow max deviation of 1:100 of its height. For 30 meters mast it is max 30 cm at the top! I would not call it a little, that’s couple hundred meters over 10 km. One of the cheapest ways to improve this is to top the mast with separation crown with additional set of guy wires.

Stiff masts are also nicer to service (you simply feel safer on one)

Welding quality is a key to safe product in mast business – and we are serious about this. In Altruss we do weld only in TIG process and with best possible equipment by Fronius and Kemppi. On top of this we use certified rods by ESAB to all sensitive works and AirLiquide argon gas in 5th grade of purity. All welders are well trained, and their job is randomly checked, plus samples are destroyed to see if the weld had right amount of penetration.

Alternative to the TIG process is MIG – which is quicker, needs less qualifications, easier to master – but controll over weld penetration is inferior. In Altruss we use MIG process only for steel where above problems do not occur.

The main reason to use separation crown is to separate antennas from each other accordingly to producer specifications. Antennas have backward radiation that may lead to interference and high noise bed. Because electromagnetic radiation force decreases with the square of the distance, even small separation is sufficient to improve the situation.

Second task of a separation crown is increasing the mast torsional stiffness (with additional set of guy wires). Truss masts are quite robust for vertical forces (inherit feature of a truss), average for horizontal forces (thanks to guy wires), and relatively non resistant for torsional forces (hence idea to help here). Twisting is most problematic during high winds and service jobs. This is especially problematic for radiolink, because it may interfere with or even break connection.

Telecommunication mast, as each truss construction has nodes or joints, that are the most robust places in the whole structure.  Every force we use on the mast shall concentrate around these nodes, no matter if during building or choosing a place for guy wire mounting points or finally when mounting antennas. The node is a place where cross members meet on the corner pipe.


Masts and towers, both aluminum and steel are constuctions of high risk. Damage may cost loss in property or even life, so it is good to service your mast before it breaks.

Aluminum masts are resistant to corrosion, but not so much to frost cracking. Once each year, in spring preferably, qualified personel should chceck for any signs of frost damage. Any cracks found shall be welded, some poles echanged for new, and drainage patented. Altruss masts are well prepared to handle unwanted water, so less prone to frost cracking.

Second issue –  guy wires. In older installations it was usual to use 3 mm wires. Most of them were zinc-plated years ago and now are very fragile because of corrosion. We recommend usage of good quality guy-wires 1×19 type, minumum 4 mm made in Europe  – even for smallest masts.

Third thing is guy wire tension – this has to be corrected due to natural wire wear that results in wire lenght increase. Always chceck with mast producer what amount of tension shall be used. If possible measure it (some tensors have a gauge for this).

Aluminum towers are much more robust and require less work. All that has to be checked is: signs of frost cracking and corrosion to the bolts. Once in 5-10 years a verticality check is suggested (done by land surveyor). As gound under the towers settles unevenly the whole tower may change its centre of gravity. This can be changed with correction rings.

In case of steel constructions a anti-corrosion checek must be conducted, and any stained spots must be repaired. During u-bolts change (and other metal on metal components as well) we shall take under consideration electrochemical potential of used materials. High difference here may lead to amazingly quick corrosion that may be dangerous for the structure rigidity.

Yea, our static engineer can prepare projects and calculations both in German and/or English plus we can comply with all European so called „National Annexes”. We do posses most of the country specific norms, but if we do not, and you do – we will work on your set of documents (verify copyright before sharing).

If you are not familiar with Eurocode idea  – we can work with your design/engineering office, or legal office that handles the paperwor for you. Here are some basic facts about Eurocode