Dual 811A Coil

Introduction

This was the first “real” Tesla coil I ever built (I made it soon after my SGTC I, which was cobbled together using old TV parts). The original version was constructed in the second half of eighth grade and I later improved it in the following year and a half. Choosing a vacuum tube coil as my first serious Tesla coil project was very rewarding because it worked the first time I turned it on, provided me with more control than a standard spark gap coil, and served as an excellent stepping stone for my later solid state Tesla coil projects.

Design

Construction

Version 1:

Spark Length = 3″