Is the receiver SK664 compatible with sensor SK602-1?
No, they are not compatible.
The SK664 is a SK6 series receiver, and the SK602-1 is a QH series sensor, so they are not compatible.
We don't have motion sensor for the SK6 series, so there is no motion sensor compatible with the receiver SK664.
For the QH series SK602 kit (one receiver and one sensor), the compatible sensor is the SK602-1 (white) and the SK602-1G (grey).