I run master work sheet, with the different records for msg, position and AC, gained from different times of the day and days, put together then an average obtained of all entries, which may/hopefully cover that change of data per trf load, weather etc, in our message, position and AC data fields. Trick is to grab data from different times of the day etc and generally a certain gain setting will tend to be obvious, within a couple up or down, which might indicate a good average overall. The general trend that the message and position fields are pretty similar gain setting but the AC seems always to need a higher gain, but the figure that stands out from message and position, is pretty close to the AC figure, may be 2 or 3 aircraft lower. But then again, just to make it a bit harder, the AC gain settings might have say 6 db settings that all will give say 30 AC but the db figure will be a little different each one, not close together I.E. 22.9 28.1 17.2 etc
