The high quality synthetic single crystal quartz resonator mounted in
a casing of 3 mm diameter with 8 mm length has been developed for the
cryogenic temperature sensor covering with the wide range from 400 K t
o 4.2 K under thickness shear mode operation about 28 MHz through eith
er extended cable connection or wireless radio echo telemetric transmi
ssion from the resonator. A wireless echo sensor system of quartz cryo
genic temperature sensor system has been constructed acid tested for a
n application to cryogenic temperature control.