Two toroid ferrite cores, as tested with 5 turns each of wire coil, shows 35microhenry and 100 microhenry on inductance meter. Which core should be used as step up transformer, at very low current, with input 6kv cable primary to 24kv secondary side. The 600PF capacitor discharges into primary and has L + C resonance . This becomes a faster final spark somewhere between micro seconds and milliseconds. Please advise which core should be used. FT240-43 or FT240-31 . The dash 31 unit has higher inductance. The spark in higher TIME is desired. The frequency /period as relates to L + C value?
