This was built as a result of this  incident with a neighbour. The coil here is shown with a static gap, but now has 200bps SRSG

(Javascript needs to be running for these YouTube videos) The 8 inch on a Pole Pig. 4.7 inch coil inside a Faraday cage. 4.7 inch coil Streamers. Tuning with an Oscilloscope.

This shows how an initial 'streamer' can occur and heat up the air immediately above it. This makes the air more conductive so a fresh streamer follows the line of pre-heated air and makes another streamer. This in turn heats a new path higher up, and so the cycle repeats. Each new streamer following the same winding path of the one underneath.





The fluorescent tube above the coil is switched off and is glowing solely from the RF energy of the coil.