The only software we know of, that could convert or at least work with both .sm3 and .sm2 files, would be XPMPro spectrum analyzer. Probably used or attempted to resave version 3 to version 2 of the same format.
Convert RHK Technology proprietary file format to RHK Technology proprietary file format.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert sm3 to sm2 on Windows
XPMPro is spectrum analyzer for Microsoft Windows. XPMPro offers feature-filled analysis and processing techniques that will powerfully illustrate every hidden and novel feature awaiting discovery in your data.
Convert from sm3 file
to sm2 file
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.