The CPT 609 ADELT is unique in that it is the world's first radio/radar and satellite Transmitter Locator Beacon. The CPT 609 is a derivative of the highly successful CPT 606 ADELT. The CPT 609 comprises homing transmitter on 121.5/243 MHz, radar transponder on 9 GHz compatible with aircraft or ship's radar, and satellite transmitter operating on 406 MHz.
The satellite transmitter operates as follows. The beacon is programmed with the country code and the aircraft registration marking or radio call sign. When the Beacon is activated by deployment into water, the satellite transmitter transmits its programmed information as a burst of coded signals to the orbiting COSPAS/SARSAT satellites receiving on 406 MHz. The message is stored by the satellite and downloaded to the nearest Local User Terminal (LUT) ground station. Here the signal is processed to obtain latitude and longitude of the aircraft in distress and its identity. This in turn is passed to a Mission Control Centre (MCC) which routes the information to the Rescue Co-ordination Centre (RCC) nearest the incident, from where search and rescue forces will be sent. Accuracy of the 406MHz signal is to within 1-2Km; although testing has proved accuracies of 0.2Km can be achieved.