The Tactical Air Navigation (TACAN) System is a line-of-sight, beacon-type, air navigation aid that provides slant range, bearing, and identification information to TACAN-equipped aircraft in determining the aircraft’s position relative to ownship. The TACAN system consists of the TACAN Transponder Group AN/URN-25 which operates in conjunction with a solid-state, electronically-scanned, Shipboard TACAN Antenna Group OE-273A(V)/URN, complete with integral monitoring and built-in fault locating capabilities. This AN/URN-25 is a dual TACAN system that includes two transponders which provide back-up in case of a transponder failure. One transponder serves as the primary while the other serves as the secondary.
The AN/URN-25 TACAN Transponder group is a full service transponder, which provides TACAN-equipped aircraft with range, bearing, and identification within a 300 mile radius, when coupled with a suitable antenna.
DME equipped users are provided range information within the same radius.
The transponder has a 252-channel capability, transmits 3kW peak power, has built-in monitor and test capability and is completely solid state with the exception of redundant ceramic triodes utilized in the transmitter. The unit drives all existing mechanically rotated TACAN antennae and has been designed specifically for the state-of-the-art electronically modulated antenna groups.
The modern design of the transponder includes modular construction, use of digital techniques, emergency mode operations at reduced power, and a dual configuration in the event of a failure. Included among the beacon’s many features is a 1 minute channel change capability.
The AN/URN-25, sponsored by the U.S. Navy, Naval Air Systems Command, is designed to military specifications, which requires full qualification for installation in surface ships, transportable vans, and fixed station sites. the beacon employs the same reliable techniques and knowledge
developed through NavCom’s 30 years of TACAN design and production efforts. It is the only modern, high power system to have received U.S. Military Service approval and to have completed it’s seventh build cycle.