To the editor: The recent article on eLoran (“Loran to become eLoran,” issue No. 170, May/June 2008) states that loran C went into operation in 1980. Not so. In 1965 I served as a technician at the Western Pacific master station at Iwo Jima and at that time loran C was already in wide use in several chains around the world. Iwo Jima also served as the master for two baselines of loran A, which continued in use for many years after loran C was introduced, as many users had only loran A re7ceivers. Your readers also might be interested to know that even then we were using rubidium-based atomic clocks to allow the slave stations to run free at night. This was necessary as the sky-wave signals at night overwhelmed the ground wave and the slaves could not accurately track the master to wait for the proper coding delay to transmit their own signals.
— Robert H. Calves is a sailor and a former Coast Guard senior electronics technician who lives in Urbanna, Va.