Propagation Predictions for April 2015
Monthly HF Propagation Predictions from Gwyn Williams, G4FKH.
Data download -
The figures represent approximate S-Points.
The colours represent expected circuit probability, i.e. Black = low to very low probability, Blue = good probability and Red = strong probability.
Further information on the data
This table has been compiled utilizing the ITURHFProp prediction program engine, this code has been developed from ITU-R P.533 and was coded by Christopher Behm, US Department of Commerce, Boulder, Colorado. The program wrapper used was adapted by Gwyn Williams, G4FKH from the old REC533 program by VE5ZX.
Clicking on a path name will produce a BMUF/OPMUF (Basic MUF/Operational MUF) graph, depicting the two best bands for the path.
The table represents median path predictions during quiet geomagnetic conditions and should be used with the following in mind. The monthly, cyclic and seasonal changes throughout any sunspot cycle are different because the sunspot and solar activity is either decreasing or increasing. Sunspot cycles are variable, some are very active whilst others are quiet and of course most are between these extremes.
To assist in the understanding of the table it is best to know where a specific station fits into the scheme of things.
These predictions were prepared for Mr Average Radio Amateur, using an average radio with a dipole type aerial, in a quiet urban environment. If a particular set-up is superior to this, it will be necessary to adjust up 2 or 3 s-points and conversely if the set-up is less well off, then drop down 2 or 3 s-points. The percentage probability remains roughly the same. However, it may be that some amateurs will never hear stations at the times when the numbers are in black.
As just mentioned the prediction engine ITURHFProp has been utilised for the above predictions and is freely available for personal use.
The ITURHFProp program as given is a command line program and is quite involved, only those with good PC and propagation knowledge should attempt to utilize it.
Please email your comments and suggestions to g4FKH@sky.com