I'm lost, I can't figure out why so many of your chokes work. I had a handful of them and none worked, Trust me I tested them.
Now, the choke I sent you as I mentioned when voltage goes so high across that choke, It will start to arc internally and burn itself up. There are 2 things that can happen to these chokes.
1. The voltage from the choke gets so high, "it arcs and burns." (Only seen with a stronger transformer.)
2. The choke will smoke due to (Frequency) and not voltage or current. (RF Burn.)
The Rf Burn, I seen this with another choke I have. There is evidence on my choke you have, that much higher voltages has been applied to it than what the big transformer can offer. Its as if the choke becomes a Capacitor and arcs internally.
I can't seem to understand how so many of your chokes work, For me, only that one choke worked. All I can say is (I wish I were there.)
Also, I sent a transformer with a very High secondary resistance. This could be the cause of some of your chokes working. When I origonaly tested the choke and found that it was abnormal, It was on a much smaller transformer which generated much larger voltages.
(Perhaps you can find a choke that will not work.) Rather than finding chokes that does work?
I can send you some more chokes that I know does not work, and if they work for you something is wrong. This leaves me scratching my head, As I tested several chokes which lead me to believe it was uniq, Now every choke you pick up works? I'm confused at the setup.
I say keep your cores that work, and when others have problems gaining the voltage, Give them or sell them a choke that you know works. This way everyone can test together.
You guy's seem to be gaining HV across tap water, Just as stan mentioned. Perhaps one day it can be Tuned, or increased?
Something strange is Indeed going on, and I feel as if it should be taken a step further.