Automatic central battery-operated telephone set. Double interior sound system. This is the model that Telefonica installed for its subscribers.

Coaxial submarine cable consisting of a copper core surrounded by the following consecutive layers: copper wires, polyethylene, copper foil, polyethylene in helical form, two layers of copper foil, fabric, tarred jute and steel in the form of a copper core....

This is a punch tape transmitter. It is used for the transmission of teletype texts that have been previously punched on paper tape. It emits 400 characters per minute.

PROVINCIAL AUTOMATIC TELEPHONE DEMONSTRATION EQUIPMENT

ENGRAVING

ROTA BASE

Exhibition Crystal Palace.

COAXIAL CABLE

COAXIAL CABLE : CABLE TRUNKING

COAXIAL CABLE : CABLE TRUNKING

CANALISATIONS : CANALISATION OF PLAZA DE COLÓN, MADRID

CANALISATIONS : CANALISATION OF PLAZA DE COLÓN, MADRID