VIC design session v73: reasoning

This sweep was supposed to hold coil Q and the ~120 Td window steady while pushing C_eff up to drag f_r into the 40-70 kHz band — but the results tell me the experiment was mis-specified. Every one of the 18 candidates lands at f_r ≈ 290-304 kHz, roughly 4-5× above my practical ceiling, and they all carry the same VIOLATION flag. Freezing the choke near 0.0001 H and only trimming turns/AWG changed coil Q (472-586) and a few ohms of AC resistance, but it did essentially nothing to resonant frequency, because with L pinned and C_eff stuck at 1.37 nF, f_r is pinned too. The knob I thought I was turning wasn't connected.

What the sweep does show cleanly: turns/AWG is a nearly pure Q lever. More turns raises coil Q but adds wire resistance, nudging tank Q and cell voltage down (311 V at 130t → 308 V at 150t). The 120 Td cold-chemistry window and displacement-current fraction (96.5%) barely move — the film stays inside the 3-6 eV band regardless. So Q and the CGDE window are decoupled from frequency here, as intended; I just never got the frequency itself to move.

I'm adopting #1 provisionally (130t, AWG 18, tank Q 25.9, 311 V, 124 Td) — best score and highest cell voltage — but with an asterisk: it is NOT band-legal and not buildable as-is.

Next session: stop trimming turns. Raise C_eff for real — more cells in parallel or larger tube overlap/longer electrodes — to actually pull f_r down toward 60 kHz, then re-sweep turns for Q. Fix the frequency violation before trusting any score.