Telegraph
The telegraph was a communications technology developed on Earth, during the 19th century.

The 2269 Excalbian recreation of Abraham Lincoln referred to Uhura's communications system as a "voice telegraph device." ()

In 2369, Worf used components of a telegraph, in combination with his communicator, to create a personal deflector shield against projectiles in the damaged holodeck simulation of Deadwood. ()

While a salvage team lead by Miles O'Brien was stranded on Empok Nor in 2373, it was suggested that if the field coils in the deflector grid were modified to emit a series of covariant pulses, while the power was boosted to the induction grid, they could use the station "like an old-fashioned telegraph and tap out an SOS" to send to Deep Space 9. ()

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Communications technology