RadCom online Propagation Prediction Tools

Every month RadCom magazine carries HF propagation predictions to more than 30 locations.

However, these can’t account for stations with high-gain antennas or for radio amateurs using more sensitive modes, such as FT8.

After much discussion it was decided that the only way to accommodate these was to develop an online tool that lets the user select different characteristics that suit their particular station.

There are now two tools available.

The first uses the VOACAP propagation prediction engine, which has been in use for many years. Developed by Jari OH6BG, it lets you specify your location, mode, power and antenna gain for each of the amateur bands.

It then produces coloured charts for each path showing the reliability of a contact on each band. Hovering over a square will give you more information.

You can find the tool at http://www.voacap.com/radcom/

New ITURHFPROP propagation prediction tool

The RSGB’s Propagation Studies Committee (PSC) has released a new propagation tool for amateurs, based on the ITU’s ITURHFPROP program.

The new tool gives you hour-by-hour monthly median propagation predictions from a location you specify to one of 28 locations around the world, in line with the printed RadCom predictions.

Predictions are performed between the user’s position, expressed as a Maidenhead Locator (or the default value of IO92 if not specified). In some cases, performance for both long and short paths is evaluated.

The results are presented in tables, with colours used to represent the Basic Circuit Reliability (BCR), and numeric values to indicate the predicted median receive power (expressed in S Levels). For clarity, power levels below -121dBm (S1) are not shown.

As well as specifying your mode (SSB, CW, FT8 and others), you can also choose from a wide range of antenna types at both ends of the path. A tool to select your noise level is also included.

The tool also loads the results two at a time so that you don’t get an awkward 20+ second delay while the computations are completed.

The details you input are cached, so that you should not need to change them the next time you use the program. You also have the ability to print out the month’s predictions as a PDF file.

The tool is the work of programmer and PSC member James Watson HZ1JW, whom we wish to thank.