Force-frequency compensation applied to four-point mounting of AT-cut resonators

For precision applications, where ruggedness is required, it is necessary to mount AT-cut resonators at four points. This note considers mounts consisting of pairs of diametric edge attachments. A locus is found for the angles of attachment to circular plates such that radially directed edge forces are compensated. One locus point is found to be particularly frequency insensitive to mounting errors and defines the optimal setting for the four-point mount.