Tuesday, August 30, 2016

Terrain analysis

If you're studying the performance of your antennas over real ground including the surrounding area you need to have terrain analysis software like HFTA or Radio Mobile. HFTA can be found on the CD included with the ARRL antennabook, I haven't got it unfortunately. Radio mobile can be downloaded or you can use the online version. I chose the online version. It has no guidance, so you have to find out for yourself. But so far, there seems not to be too many options as the program is under development. However you can get the idea and it could be really useful. Of course radio mobile is all about mobile coverage but since this is calculated with surrounding terrain in mind it could be interesting for a base station as well. My omni directional copper tape vertical isn't something really shocking and that count as well for the heigth of 9m above ground level. The biggest surprise is that my coverage seems to be better to the south (land inward) and not to the north (the sea). I made several coverages from 80 - 10m and the outcome is all the same. It seems that the Island of Borkum near the coast here is blocking my signal as well. You can see the same with other islands. Playing with the software and several antenna models can get you interesting surprises. Radioamateurs which are living in the mountains or near the sea or a lake can have most advantage from it. But remember, Radio Mobile doesn't give you any idea about the DX performance as it is actually a mobile station coverage analysis program.

Radio Mobile Online

HFTA (HF terrain analysis) will show you more info about take off angles in several directions which are much more important for DX. I would like a copy but need to buy the ARRL antennabook for that I guess. It is so unfortunate we can't download the software somewhere on the internet? It has probabely a copyright by the ARRL. I think I have to look out for the book which we cannot buy here in the Netherlands as far as I know (sold out at the VERON).


  1. Hallo Bas, een leuk artikel over Radio Mobile en HFTA.
    Het RM programma ken ik QRL-matig al jaren en wij maakten dankbaar gebruik voor het opstellen van basisposten e.d. Zeker de klant was zeer gevleid met mooie prints hoe de afstraling zou zijn en het dekkingsgebied. Zeker in onbekende gebieden was dit een uitkomst en het klopte vrij aardig.
    73 Hans, PE1BVQ

    1. Ja het is een mooi programma. Meer geschikt voor VHF/UHF maar goed. Je krijgt een beetje een idee. 73, Bas


Thanks for your comment. Bedankt voor je reactie. 73, Bas