Automatic central battery telephone. Interior buzzer.

Central battery-operated automatic telephone set.

Receiver of an RL-4 radio link repeater. It is part of a microwave radio relay system, with intermediate repeaters, analogue 4 GHz frequency with the capacity to transmit 960 telephone channels simultaneously, used as a communication link....

BAKELITE STANDARD ELECTRIC

Madrid's international interurban network, through which Spain's communications with other countries pass. Gran Vía Central Station.

BROADBAND : RADIO RELAY LINKS : LA MUELA

Main door of the central building Pi y Margall, 2. Central de Gran Vía.

COAXIAL CABLE : SPLICING PROCESS

COAXIAL CABLE

SCHOOLS : COURSES IN SCHOOLS

TRANSPORT : EBRO TRUCK