Magnifying Transmitter

The 3-coil version of the Tesla coil, commonly referred to as a "Magnifier," which utilizes what Tesla coined the "Extra coil." It's most known for its use in the Colorado Springs Experimental Station, but was also used in New York at Tesla's Houston Street lab and was a primary component of the Wardenclyffe World-Wireless System.

The magnifying transmitter, an evolution of the Tesla coil built in 1899 at Colorado Springs, was a massive resonant transformer designed to generate millions of volts and produce 130-foot lightning bolts. It aimed to transmit wireless power and signals globally by creating standing waves in the Earth's atmosphere and ground.

Intended for the Wardenclyffe Tower project, it represented Tesla's vision of free wireless energy. Though unfinished due to funding issues, it advanced understanding of high-voltage resonance and influenced later radio and power transmission experiments.