Yes IO540, with both pointers overlapping with one pointing ahead and one pointing behind you must be on the centrline between the beacons. If you drift right , both arrows point left (the way you need to go) If you drift left, they point right.
Makes it almost very easy to complete the approach. The problem is when in typical ADF fassion, one points left and the other right and then when you bank, you get dip added to the problem
Regards,
DFC