And what should that do? Change the tuning? Also, how do you recommend adding more tubing on my setup. I have about ten more feet in my house, available for use, but I'm not sure what to do, as it would go off the platform. Also, I tried using on the driveway, but it was on the ground, not a milk crate. I have a crate though so is it worth a try? Would it lead to more output, or do I still need to add more turns?
Well, here's the situation right now:
Your coil should be out of tune, but it isn't... The reason is the walls/ceiling/bench etc around it is creating a short path for the RF between the topload and the HV Return (secondary ground wire). So it's forcing the frequency of the coil low artificially by eating up power. The lower the frequency, the more turns you need on your primary to tune it properly (in other words you have to move the tap further out, to 6, 7, or even potentially more turns - bad).
Because your coil is where it is, your tiny sphere topload is working. If you move it out, it may not tune with that small sphere, BUT you'd have maybe 20-30% more power, the same amount that is being eaten by the environment right now.
Because you're using a tiny sphere you aren't storing enough charge in a topload for good output, AND you're getting multiple streamers instead of one long one.
So, you have a choice: Leave it where it is and call it finished. Or, move it outside away from things to couple to and place it on a milk crate (being too close to the ground does the same thing, it's another surface to eat power).
If you move it outside you'll have to retune it even if you keep the tiny sphere, but you'll gain some output because the environment isn't eating power. Outside you should be able to put on a proper topload, something in the neighborhood of 12" x 3" at least, if not larger, like the one you initially described to me, or like Nospin said to make with pie tins and dryer ductwork.
You should be ok sticking to the turns you currently have (7 max), but if you put on a very large topload or your tank capacitance changes sufficiently, you may not have enough turns to tune it, which results in a very big pain in the ass situation to fix. You will need to "sweat solder" on more tubing using a copper plumbing coupling designed for mating two pieces of that diameter copper, a propane torch, and a suitable plumbing solder/flux set. Since the platform isn't wide enough you'd need to get a larger one.
I had to do exactly this entire circumstance on my second SGTC, as documented in the first pages of this thread. I had taken the coil outside for a first full power test and got NOTHING for output because 1) I didn't elevate it off the ground, 2) I didn't have enough turns on the primary, 3) I added a large topload after initial testing. What did I end up doing? I remade the entire platform, soldered on four more turns, and retuned the entire thing. I went from 3" arcs to 17" lively streamers. It was a pain in the ass.
