TC construction was fairly easy using a "kicker coil" from Science First (cat# 26-2010; Buffalo, NY). With this component you won't need to build a separate spark gap. Just wire your caps in series with the included gap along along w/four pancake turns of #10 grounding wire. for the primary as indicated in the basic schematic. Then wind about 400 turns of #24 magnet wire for the secondary. I found a wood sofa leg and wrapped it in plastic mailing tape to make the secondary coil form.
Connect a 2.5 amp variac to the input lugs of the step-up coil which will kick up line voltage several notches; subsequent increases in voltage occur as the primary circuit resonates w/the secondary. Top off the secondary w/a donut shaped wood form covered w/copper tape or foil. Attach a power cord to the variac and mount everything in/on a wood box. I threaded the primary wire through pre-drilled holes of plastic strips cut from coat hangers and then screwed the assembly to the box top. Lastly, accessorize w/neon indicator lights, an On/Off switch, fuse and bold warning labels.
A professional coiler bench tested the TC and recommended a second capacitor deck for a total of 0.01 uFd. This mod led to almost 5 cm sparks at a resonant frequency of 1.07 MHz.. BTW, there's a small DC fan located under the gap to cool the contacts. The 12 V DC supply was positioned in the upper right corner of the box and ran off the variac.
I mounted two mini fluorescents on either side of the secondary as light sources. When the spark gap was adjusted for the lowest variac setting, the night light ran continuously for 4 hours! The internal components were barely warm to the touch.
Caution: As w/any line powered TC, even this small unit can bite like a cranky piranha if disrespected. So use care when the project is powered up and never operate it unattended.