Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx> Hi Dimitry, Tesla list wrote:
Original poster: dest <dest@xxxxxxxxxxxxx> Hallo Bart. > Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx> > On my large 13" diameter coil, I witnessed racing sparks > running down from the top then abruptly arcing at 2/3 down the coil > right out to the strike ring. interesting, i`ve never read about racing sparks at the upper 1/3 of sec - certainly not transformer action at work here : ) looks like simple surface tracking, maybe toroid was too high, or it`s surface had direct electrical contact with the outer surface of secondary?
The arc tracked straight down the side of the coil then suddenly broke out to the strike ring. I witnessed that occur several times. This was in my early coiling days and nothing was quite "right". It could have been tuning, or whatever, but I will never forget it. Haven't seen it since (maybe I'm learning something?).
Oh yes, and maybe this past week, I found a reason to use one (finally!). I was taking some snap shots of my little coil for someone and I was getting many primary strikes. Well, all of a sudden, the coil just stopped work. All was silent. I figured I had killed one side of my NST. I quickly shorted to a narrow gap and it worked. I then hooked up my HV divider to the NST and measured each side. One was 6,300 volts and the other ZERO! So yes, I killed the NST. Maybe a strike ring would have prevented it.it seems these days we need not just a scope, and not just a storage scope - we need a usb scope plus pc with raid of say 1tb to observe what`s going on really, luckily such stuff is not rare or very expensive these days : ) > BTW, I no longer use a strike ring. that`s good subj for whole another topic % )
I'm writing a paper on my depotting experience for this NST. OH, the fun I had!!! Anyway, the coil is up and running again and much better than before!!! I'll post my NST depotting experience later. BTW, due to field control, I haven't had a primary strike since rebuilding the NST. I may still force myself to add a strike ring however.
Take care, Bart