FlightGear Forum
I've taken a liking to the 21 and would like to use it to run my navigation practice/lessons. Instead of the left-side MFD radar display, I've substituted a second HSI. I noted a second ADF[1] in the property tree and have also noted that the "indicated-bearing-deg" values for ADF[0] and ADF[1] are identical.
I cannot find which source file provides the calculation for these deflection values; even looked inside the generic aircraft, instruments, and nasal folders for the source. 
Does someone know where the source value calculations are made? Please point me in the right direction.Cheers.