When this is the case, if discharges are made across the spark gap oscillations are excited in the closed circuit, and these induce other syntonic oscillations in the antenna circuit.
Marconi in an operative system of syntonic wireless telegraphy.
Slaby in Berlin shortly afterwards made a similar exhibition of syntonic electric wave telegraphy' O.
Lodge had previously described in 1897 a syntonic system of electric wave telegraphy, but it had not been publicly seen in operation prior to the exhibitions of Marconi and Slaby.'
Lodge was, however, fully aware that it was necessary for syntonic telegraphy to provide a radiator capable of emitting sustained trains of waves.
At a later date a syntonic system comprising, as above stated, an antenna directly coupled to a resonant closed circuit was put into operation by Lodge and Muirhead, and much the same methods have been followed in the system known as the Telefunken system employed in Germany.
A method of syntonic telegraphy proposed by A.
Inst., 16, p. 247; id., " Syntonic Wireless Telegraphy," Journ.
When this is done we have a syntonic system which is not easily affected by electric waves of other than the right period or approximating thereto.
This arrangement is called a non-syntonic receiver.