The Tesla coil uses high-frequency transformer action together with resonant voltage amplification to generate potentials in the range of tens to hundreds, or even thousands of kilovolts. We describe a range of experiments designed to investigate the Tesla coil action, ending up with the design and development of a touring Tesla coil with a carefully considered trade-off between portability and performance. The apparatus plugs into a standard 230 V wall socket, drawing an average of 7 A, and features a telescopic, collapsible secondary coil. The assembled system stands almost 2 m high and yields sparks up to 1.5 m long, giving it physical stage presence which makes for memorable demonstrations, even in larger venues.