International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A digital device for rapid acquisition of the initial phase of PN code has been implemented. The principles and results of the experiment are introduced in this paper. The m PN code is modulated on IF with BPSK type. The cycle of PN code P=255 chips. The rate of PN code R=5.1 × 10 chips /s. The IF is not acquired. The shift in Doppler 6 frequency f is within l-4KHz. In these conditions, the phase of PN code can be acquired d within 3 ms and the error of sychronization is less than 0.5 chip.