VOA Prop
Many thanks to SWLing Post contributor, Paul Evans, who notes:
Users of these two propagation prediction programs will find that they don’t work beyond Dec 2019 because the SSN look-up files didn’t go any further.
I noticed this 2-3 years ago and added to the end of the files required. I entered guesses for solar activity values, but with auto mode turned on they will fetch current values. At least this will get you started again. Or my guesses might be right!! 🙂
For Ham CAP use: http://w4.vp9kf.com/SSN.dat
For VOAProp use: http://w4.vp9kf.com/ssndata.txt
Download them and swap them into the directory where the application is located.
Thanks or the help, Paul!
NEW FORMAT of SSN file
You can replace actual file (ssndata.txt) in your VOAProp folder (January 2026)
Line in ssndata.txt file marked as 2025 contain SSN data for current year 2026. This is solution of VOAProp program limit for maximum usable year 2025 because of no exist program source code.
VOAProp will indicate year 2025 perhaps for ever, but all other data (Month, Time, SSN, SF, A and K) will be up to date.
https://www.ok1dub.cz/wwv/