ADF Dip
In some ADF installations the ADF needle 'dips' towards the low wing in turns. This effect is most noticeable when flying directly to or from a beacon (both head and tail dip in the same manner, depending whether you're tracking to or from) and is zero when the statrion is on the beam. Dip is typically a maximum of around 10°. Whether you get dip or not depends on the antenna; old fashioned 'towel-rail' antennas are dip free but the small Bendix King antennas using the 'Bellini-Tossi' system that you'll find on most spam-cans suffer from dip. It's just one more thing to cope with on the IRT!