First Marconi transmitter

This is a copy of the transmitter and the receiver that Marconi used to send a coded message at a distance of 1.75 miles near his home at Bologna.

The signal was transmitted using a spark-gap device, while the receiver was based on the coherer invented by Temistocle Calzetti in 1884 . It is interesting to note that since the spark-gap device radiates pulse signals, the first communication system was basically 'digital'.