Build a Tesla Coil (the way Tesla built them)

Calculations and Preparations

Starting guide: wind a coil with a height-diameter ratio around 1:1 with an air-gap between turns of at least half the wire diameter.

Calculating Wire Length https://Hakasays.com/DollardTeslaCoilCalculator
or:
297/F = L
F = frequency in Mhz
L = wire length in feet

Note that due to dielectric effects, a Tesla Extra coil has a higher frequency than is predicted by normal 1/4 wavelength formulas. We call this the ‘velocity factor’ and it is directly related to the height-to-width ratio of the coil.

Framing Material Selection

Best: UHMW, HDPE, LDPE, PTFE(Teflon), PP
OK: Polystyrene
Meh: Polycarbonate, Acrylic, Epoxies, PVC, Wood

Sadly, this means that hardware store plastic sheeting just aren’t going to cut it. But HDPE buckets from the paint section…….

3/16″ to 1/4″ thickness works good for coils 3-12in in diameter
Plastic sheeting is usually sized in 12×12″ sections, so cost-efficient diameters are around 5-5.5″ and 11-11.5″
White/light plastic have lower loss characteristics
Material selection has a higher impact at higher frequencies

Wire selection:

The general goal here is to get the lowest resistance practical.

Obviously few people can afford 100ft of 0 gauge copper bus-bar to wind a coil, so compromises must be made. Generally we recommend not going below 20awg though as the loss characteristics begin to compound making a very high Q coil difficult to achieve.

Silver-coated Teflon wire
Silicone-coated wire
Litz wire
Coax cable can also be used to create a large effective diameter coil by using the outer ground conductor (per Eric Dollard)