Until now in thermocompensated crystal oscillators (TCXO) the compensating action was estimated as a function of one variable -environmental temperature. At the same time experimental data &ow that TCXO frequency stability is essentially dependent on temperature process dynamic parameters. The more drastic is the temperature variation the more is decompensating effect.In this work the origins of this phenomenon are analysed and the ways are shown of reducing its effects. A new in principle apprcach is suggested according to which the compensating action is formed as a function of two wariables: the temperature and the rate of its variation.A theoretic substantiation of this method is given. Structural circuits of devices perfoming the temperature dynamic compensation are suggested. 'Ihe experimental investigations of EX0 with m i c r o p r ocessor based temperature dynamic compensation system confirmed the possibility of essential TCXO frequency stability improvement in nonstationary them1 conditions. In a system using AT -cut resonator and a separate Y -cut thermosensor the application of the temperature dynamic compensation resulted in ten times actual stability rise as compared to the conventional digital thermocompensation procedures. Even with dual-mcde SC-cut resonators the application of the temperature dynamic compensation proved to be useful. I m I o NTemperature compensated crystal oscillators (TCXO) are widely used in self-contained miniature equipment especially in cases when high stability is needed alongside with economical efficiency and short operational readiness time. It is characteristic of such devices operational conditions that rapid environmental temperature variations are possible while with small mass nnd nbsense of heat isolation the smoothing effect of the case is lowered. In such conditions the crystal resonator, thennosensor and other elements of the oscillator , Moscow, Russia are d e r the actions of fast altematimg temperature fields which results with deteriorated t h e m compensation. The phehomenon of TCXO stability deterioration under transient thermal effects is well known h t at present the problem became especially acute. The matter i s in digital control methods applied now which ensure high accuracy of compensation function. As a result the other components of frquency nonstability became more evident, those with analoque compensation system imperfections. Hence, to create a high stability TCXO it is not enough only to step up the compensation accuracy under slow (quasistatic) temperature variations. It is quite necessary to take steps of lowering the effects of temperature shocs and sharp temperature variations.The above mentioned effects had been described earlier [l and oth.] hut it is our opinion that the phenomenon of TCXO d m i c discompensation has not yet been fully investigated. Furthermore, the ergineering solutions are &sent which could ensure the increase of temperature-dynamic frequency stability with practicaly any kind of TCXO construction, using only pure c...

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