not if both sectors use different frequencies… are you in SFH 1×1? Even though, the BCCH would not hopping, and i assume your sdcch timeslot is located on the first TRX, am i right?
0.4% call drops due to transmission is bad. can you split the DCR per TRX, rather than the average for the whole cell?
If yes, do you notice more transmission call drops on the TRX that carries the SDCCH?
Do you notice drops due to transmission on other sectors as well, in the same percentage?
Finally: how many calls per hour and how many sdcch requests per hour on the bad sector?