| 摘要 |
<p>PURPOSE:To enable to measure carrier frequency transmitted from each earth station directly, automatically and simply by detecting the control voltage of the voltage contol oscillator attached to the carrier regenerating portion of PSK demodulator and by comparing it with transmitting carrier frequency of a local staton. CONSTITUTION:Transmitting carrier frequency F0 of a local station is measured from the transmitter by means of frequency meter 11 and is stored in processor 14. Then, the signal of local transmitting carrier which is repeated by the satellite is received and the control voltage of vltage control oscillator VCO in phase shift and modulaton PSK demodulator 9 is detected by sample holding circuit 12 and is stored in processor 14. Then, VCO control voltage Vx of transmitting carrier originated from other earth stations is detected by circuit 12 and is compared with the local transmitting carrier stored previously. As the result of the procedure above mentioned, carrier frequency transmitted from each earth station can be measured directly, automatically and simply.</p> |
