The design of a gravitational antenna consisting of a relatively large piezoelectric quartz crystal cooled to 3 m °K is presented. Calculations show that the use of the piezoelectric output to detect signals results in a simplification of the apparatus with no loss in sensitivity as compared to that attainable with similar antennas employing magnetic‐displacement detectors. For both types of antennas the sensitivity is considerably better than that required to detect thermal oscillations at 3 m °K and compares favorably with that attainable with massive room‐temperature antennas.