https://youtu.be/M2NrTy6APVg <https://youtu.be/M2NrTy6APVg> Hello Steve, You have probably seen this but it illustrates that the secondary is vulnerable even when earthed strike rings (in this case, four large corner brass balls) are in place. The balls in fact worked perfectly but a particularly persistent rogue strike detached from the ball to hit the secondary, the primary was not involved at all. In its next reincarnation, I will use a conventional strike ring but set at a greater distance from the primary and by logic, the secondary.. Regards, Phillip. _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxxxxxx https://www.pupman.com/mailman/listinfo/tesla