The Dr Feickert Alignment Protractor NG (Next Generation) is a precision device that enables you to adjust cartridges and tonearms with an effective length from 8.6 up to 17.7 inches for correct overhang and offset.
The calculation of parameters are carefully carried out according Lofgren, Baerwald and Stevenson equations aiming at reduction of the overall RMS distortion level caused by deviations from the perfect linear tracking position of your cartridge.
The general geometrical correlation of a tracking device based on a fixed pivot point are well known since the fundamental publications of Baerwald and Lofgren back in the first half of the 20th century. The conclusion of both papers was that such a tracking device must have an angular offset with a defined overhang. The offset and the overhang vary with the effective length of the tonearm itself.
While tracking the record the stylus matches tangential position in the groove at two points - the inner and outer Null points (linear tracking position).
Once you have adjusted overhang and offset using this protractor we recommend that for perfect azimuth calibration you use the innovative software ADJUST+ (www.adjust-plus.com).
