The Cuban military has long run its own smaller but much more secret version of the Russians' Lourdes electronic spying base, a unit known as the Electronic Warfare Battalion.

Cuba does not get copies of the communications intercepted at Lourdes, only copies of Russian intelligence summaries on issues that could affect the island's security, said a former Cuban army lieutenant colonel who defected in 1992 and a retired official of the U.S. National Security Agency.

Adjoining the Russian base at El Wajay, nine miles southwest of Havana, is a Cuban-run ``parallel signals intelligence operation,'' the two sources said. It is not clear just how powerful this center is, but the defector said it could certainly pick up telephone and radio signals from Miami, 130 miles to the north.

The Interior Ministry's General Directorate for Intelligence runs a separate radio listening and transmitting post somewhere on the island, apparently to stay in touch with its spies abroad, the defector added.

And while the Electronic Warfare Battalion has the equipment to jam U.S. communications, it is not involved in the daily jamming of Radio and TV Marti broadcasts from the United States.

That jamming is carried out by a network of small radio transmitters deployed around Cuba's northern and southern coasts, the defector added, in an operation code-named ``Titan.''