Quantum Data 802BT User Manual page 678

P1
Description
668 Appendix B Image Reference
There are two main ways of correcting pincushion distortion. The first involves placing or
adjusting magnets on the yoke. This is a trial-and-error method. However, skilled operators
develop a feel for how strong a magnet to use and how to place it in order to get the
desired correction. If any correction is performed, the trapezoid distortion correction
should be repeated.
The other correction method involves adding correction signals to the deflection signal
driving the yoke. This method is usually found in color monitors, where adding magnets to
the yoke would cause problems with convergence and purity. The type and number of
adjustments depends on the monitor being tested.
This image is a 6x6 white crosshatch without a border on a black background.