OK I must object to calling these object "Tesla coils" (TC). A true TC uses radiant energy, not regular electricity. You can tell the difference by the discharge. If it is pointy or sharp looking than it is NOT radiant energy. If its feathery and soft looking than it IS a TC. The difference is in the spark gap, which is how the radiant energy is produced. Look over the patent and read his "hairpin circuit" patent where he talks about radiant energy. Notice the spark gap. Read Gary Vassilatos' wonderful book "Lost Science" for the full details of this discovery and what the differences are between electricity and radiant energy. Sorry to decent. Just had to scratch my itch. I'm sure these almost TC's were still fun to watch !