The NAPCO KY-189 is a self-contained high-level speech security device built to military specification as a rugged, submersible handset. Its design enables connection directly to the U.S. Army's current AN/PRC-77 and AN/VRC-12 series of radios as well as the PRC-1077, GRC-160, VRC-64 and other VHF/UHF FM radio equipment.

The KY-189's scrambling circuit employs a micro-processor controlled, pseudo random rolling code, combined with random timing, audio frequency shift and synchronization. The encryption algorithm provides over 100 million user programmable security codes, and a pseudo random code generator which will not repeat itself in 84¹⁰⁹ years of continuous operation! Every time the PTT (Push-to-Talk) is pressed the scrambler code changes to a new pseudo random code sequence for higher security.

Every KY-189 system (Network) user is assigned his own unique Master Code Key to prevent system access by others, and a universal key is also provided for joint operations. Because NAPCO's scrambler is an unique device it can be integrated into existing radio networks using standard repeaters without reducing the radio's operating range.

Other standard features accessed through the KY-189 fifteen character keypad include:

* ANI (Automatic Number Identification) Status and Location Report
* All Station Emergency Alert Tone
* Programmable Time-out-Timer Selective Call.

Also available as part of NAPCO's tactical security system is a base station control terminal which
centralizes all system command and control terminal which centralizes all system command and control functions. If the field units are equipped with the ANI feature, a signal is sent to the base station control terminal, each time a radio in the field transmits.

Photo courtesy NAPCO