the lack of field grading by the solenoid, as shown in Fig. 4.

![ Output during operation without the solenoid. The voltage $V_t$ oscillates with a frequency that ramps from roughly 140 to 95 kHz, as measured by an uncalibrated capacitive-pickup probe. Here, the data require time-varying RCL parameters to be fit well (see supplementary material), in contrast to Fig. 3(b) that has a more subtle ramp. Inset shows representative spark discharge for this data. Without the solenoid, discharge also occurs off the components. []{data-label="fig4"}](Fig4_McGuyer_MarxCoil){width="8.5cm"}

In addition to such static changes, SGTT circuit parameters can also change dynamically. In this case, the rough limit given above holds approximately, although it ignores possibly beneficial effects like rapid adiabatic passage.[@RAP] In contrast, the data in Fig. 4 show a clear frequency ramp from about 140 to 95 kHz, corresponding to $\delta f_0/f_0 \approx -32$%, highlighting that the MC tolerates dynamic changes. Similar frequency ramps were observed in all data including that in Fig. 3(b), for which it is more subtle. Field-sensitive ceramic stage capacitors are likely responsible for the ramp in Fig. 3(b), and together with stage-inductor saturation are likely responsible for the ramp in Fig. 4.

While the sources of dynamic 