The data of tuner configuration are on the settings in file that is located in the folder etc/enigma2 and save it with some FTP tool type DCC or the TC on computer.
Now there are two options
1. When you install a new image just replace the existing one and go to menu - shutdown and do the hard reset or just power off the box (e2 restart does not help because the enigma enigma overwrite new file). After restrat box, you will have everything set. This option use in the same type of images (say, replacing an older BH with newer) - and if possible arrange all the same as the old (skin for example ....).
2.If the different types of image- now you can copy only part of the files that are related to the tuner. Open settings file and edit it with some type of unix compatible editor like Notepad2 . The segment associated with the tuner contains phrase Nims - means all lines are what this phrase copied from the old to the new "original " Settings file (after this hard reset).