Can someone explain the corona suppression rings I've seen on some coils? Is it a closed or open loop, and how is it connected? Seems like that might have helped...
The spark gap may be too wide to fire. Cleaning the gaps, and adjusting them a little narrower may let them fire again. Also the NST may have shorted out partially due to carbon tracking in the tar. The corona ring on top of a coil prevents sparks from emitting from the top turn. It should be a closed loop and won't steal noticeable energy from the coil and won't heat up. I often use a smaller toroid right over the top of the secondary such as in my TT-42 coil. THe corona ring or small toroid is electrically connected to the secondary coil and to the main toroid.John