Quartz frequency standard with an extra-low aging rate for communication synchronization systems

The application of a modulation method to the quartz crystal frequency stabilization to decrease the aging rate of an oven controlled quartz crystal oscillator (OCXO) and the crystal standards intended for communication synchronization systems are discussed. The description of these devices, in which the compensation of long-term frequency instabilities is realized with the use of the method, is given. The results of investigations of the quartz frequency standards of q1-88 type and their general performance with and without aging compensation are presented. It is also shown that for both regimes aging rates per month correspondingly to -(6...20)/spl middot/10/sup -10/ and (3...24)/spl middot/10/sup -12/ have been reached. With this the short-term Allan variance is (1...3)/spl middot/10/sup -12//sec.