What type of transmission does Tower to the People and Wardenclyffe Tower have in common?
Tower to the People Tower to the People - Tesla's Dream at Wardenclyffe Continues is a 2015 documentary film directed by Joseph Sikorski about Nikola Tesla's Wardenclyffe Tower. The film documents the history and subsequent decline of the Wardenclyffe complex designed and built by Tesla in Shoreham, New York, as the main laboratory and facility for his experiments on wireless power transmission. The documentary focuses on the role of J.P. Morgan, one of the main investors behind the project, who pulled his support after realizing free wireless energy would hurt his own business interests. Tesla could not find additional investments and in 1906 the project was abandoned and never became operational. After over a century of decay, the tower site was rescued by a successful fundraising campaign and will be converted into a museum – the Tesla Science Center at Wardenclyffe – honoring the legacy of the Serbian American inventor.
Tunnel transmitter A tunnel transmitter allows wireless reception in tunnels. It consists of a receiving antenna which receives the signal to be radiated in the tunnel, and a transmitting antenna installed in the tunnel, which is either a Yagi antenna or a line antenna. In principle, a tunnel transmitter can work purely passively, in which case the received signal is passed over a cable to the antenna in the tunnel. Active systems, however, are more often used. In some cases the radio frequency inside the tunnel is different from the one used by the broadcaster. More often the program inside is transmitted on the same frequency as outside, in which case the information signal should be demodulated or converted to an intermediate frequency in the outside receiver, and then modulated/shifted back in the transmitter. Otherwise feedback may occur.