Thursday, May 22, 2014

New version of PropPlanner software released for Windows and Intel Macs

In 2012, I opened a web-based service at - VOACAP Propagation Planner ( This service provides VOACAP HF propagation predictions as numeric data, instead of fancy graphics. The reason is that the numeric data when filtered and processed properly offer more accurate HF predictions. And for this purpose you will need some extra software to help you. This is where my PropPlanner software for Windows and Intel Macs comes in. I also offer an Excel template which gives you CQ zone-specific summaries and thus helps create your own contest or DX operation plan.

As you know, making predictions boils down to making optimum use of the openings — being in the right place at the right time. So, the better predictions you have, the better basis for operating planning.

Nevertheless, we must remember that predictions are just that — predictions, not exact science. And in particular, due to the nature of VOACAP, you must visualize low-band openings with the help of grayline map software such as DX Atlas by Alex VE3NEA or GeoClock by Joe Ahlgren. VOACAP predictions are of less help there.

The resources needed for successfully running VOACAP Propagation Planner are as follows:
  1. Web site ( that calculates VOACAP predictions and outputs the result as numeric data, and
  2. Windows or Mac software called PropPlanner (together with an Excel template) that helps you work on the VOACAP prediction data on your own computer and make it more understandable.
The VOACAP Propagation Planner manual is available in PDF format.
Give it a go, and let me know what you think.

Thursday, May 1, 2014

Comparing VOACAP predictions - or are we?

Today, I happened to read KY6R's blog entry about VOACAP HF predictions for a path from FT4TA (Tromelin) to his QTH. Rich was comparing VOACAP Online predictions to those of Stu K6TU. Here they are:

Tromelin prediction by Stu K6TU
Tromelin prediction by VOACAP Online

To be frank, I don't know what to say after reading Rich's piece. Predictions are just predictions but, nevertheless, I felt he seemed to be convinced that Stu's VOACAP prediction is much superior to what VOACAP Online is able to produce in general, but especially on the low bands. It's of course a known fact that VOACAP cannot predict low-band long-distance propagation accurately. There are many factors involved, specifically that VOACAP does not recognize grayline propagation which will play a major role in this particular case.

But what puzzles me is this: are we actually comparing apples to apples? I believe Stu's HF prediction is not at all a pure VOACAP-generated prediction on all bands. It seems to be a mixture of VOACAP-based predictions - and something else. And that "something else" is notably visible on the low bands. It would be enlightening to know where Stu's low-band openings with the predicted signal strengths are actually coming from. Is he using a tuned-up version of VOACAP?

Please note that Stu's prediction strangely ignores a potential opening on 30 meters at 14-17 UTC, or on 40 meters at 15 UTC for that matter, both predicted by the latest officially released VOACAP. This is the time for grayline propagation, too.

I ran a comparison prediction (the same path Rich used) with VOACAP on my PC, using extremely powerful 17-dBi isotropic antennas on both ends. This was to see whether the online version of VOACAP agrees with the PC version (yes, it does), and to see whether VOACAP can predict an opening on 80M if extremely powerful antennas are used. No, it cannot.

The PC version was the latest version of the publicly available VOACAP software package. The above is the result for November 2014, SSN 85.