It is not the same for everyone
and remenber the simbol -
Sent from my HTC Desire S using xda premium
I can confirm it kinda works - obviously showing the minimum amount of signal bars cos i havent changed the framework (dont need to to be honest).
Looks like -20 is the figure used in the flashable zip here, so i'm using that and seems to be fine.
Also can confirm that you can ONLY change the calibration file with Root Explorer when mounting as R/W, no other file manager that ive used works (even with root access and r/w system etc etc).
Thanks for the help