• Choose appropriate guywire
  • Calculate lengths
  • Think about it
  • Do it
  • Regularly check it

Choose appropriate guyrope

Big antennas and masts in permanent or temporary locations are part of the essential equipment for successful amateur radio stations. Their construction and installation needs a lot of time, effort and investment. Such installations are frequently exposed to many unfavourable conditions – static pressure and dynamic mechanical tensions, changes of temperature, humidity etc. These conditions, as well as the construction of the installation itself, can constitute a serious constructional problem in terms of working life, reliability, safety and avoidance of potential accidents.

A rigorous technical solution to all the design questions connected with the construction, securing & installation of such masts & antennas is complex. In order to calculate the answers, it is necessary to put material engineering, statics and dynamics of stressed constructions together. Radio amateurs frequently choose the most suitable solution according to their personal experience. Now in many cases, thanks to their common sense, all is well, but, nevertheless, they often start with incomplete knowledge of the parameters of materials and components being used which can lead to unnecessarily expensive “overengineered” designs, or even inadequate design.

The Mastrant calculators help answer these questions and remove much of the guesswork. No two mast/antenna installations are identical, and the Mastrant calculators can make specific calculations for your individual installation’s guying requirements. After you fill in all the essential parameters, the Mastrant calculator will calculate the important numbers and guide you to the best guying materials to choose so that the installed mast/antenna has guying which is both reliable and safe and is neither over nor under engineered.

Unfortunately, the calculators cannot provide you with answers to every possible combination of mast/antenna. However, they can be used as guidance for any normal situation. The calculators will provide you with accurate & reliable results, but please remember “garbage in = garbage out”, so we suggest you carefully double check all your inputs.

You can choose the requested calculation from the menu on the left.

(If you are not overly familiar with Newtons, please remember 1 decca Newton (1daN) is almost the same as 1Kg.)

To see more details, please visit section Calculations.

Calculate lengths

The calculator (section How-to, Calculations) will work out the lengths of guys necessary for guying your mast. It will calculate for guying in either three or four different directions and one to six levels of anchoring. It permits you to select the exact guy anchoring heights for your mast, and assumes that the ground is level.

Remember to include a surplus to cover any measuring inaccuracies and the thimble termination at either end. The calculator will show you the length of the guys needed for each level, and the total length required for the whole mast.

You can study the results and decide if you want every guy to be an unbroken length, or if you want to save money and have joints. Jointing shorter pieces obviously uses the odd lengths more economically, but please do not even think of tying a knot to make a joint, do it properly with the correct hardware, otherwise a large part of the guy strength will have been lost.

The calculator works out how many reels of guy you will need in total for whichever way you choose.

Use the “Forces in guywires” calculator to work out what strength guy you need, and then you are ready to order your new guys and accessories.

Think about it

Basic instructions

Do it

Recommended procedure

Regularly check it

After final tensioning of the guys in "idle" the rope will for some time continue "settling". Check the guys and, if necessary, tension them the next day after the installation and then about 3 times at intervals of about 1 week. Then, it is very useful to check the guys after every windstorm or every 6 months.