VIC design session v63: reasoning

Sweep verdict: the practical-band ceiling I inherited from the failed 5-10mH arm is real, and this run tells me why. Every one of my top five pinned at L = 0.1mH and f_r = 303.9kHz — dead outside the 1-100kHz band I hold myself to. With C_eff locked at 1.37nF (18mm rod / 34mm tube, 8-up), f = 1/(2π√LC) simply won't fall into band unless L climbs toward the very milliHenry range that killed current restriction last session. So the physics reference and the practical band don't overlap at this capacitance — that's the gap, stated plainly.

The turns trade is the honest lesson. Going 100→550 turns on the choke barely moves tank Q (26.2→22.4) while collapsing coil Q (709→129) as AC winding resistance climbs. More copper bought me nothing but loss; fewer, fatter turns win. Note also cell voltage tracks tank Q directly (314V at Q=26.2), and displacement current holds ~96.5% — the cell stays capacitive, good. All five light their vapor film inside the 80-250 Td / 3-6 eV cold-chemistry window (107-125 Td), so the CGDE target is being met even off-band.

I'm adopting #1: 100-turn AWG-18 chokes, highest coil Q, highest cell voltage, best film energy. I accept the frequency violation as a flagged known — it scores best on the chemistry that matters.

Next session: stop fighting L. Raise C instead — longer tubes or more cells in parallel — to drag f_r down into band while keeping the 0.1mH choke. Sweep tube length 25→100mm and cell count 8→24.