I have a resonant LC oscillator I'm tuning at the moment, three phases with a PLL.
The voltage is adjustable up to around 1kv using the tank circuit at resonance. I could probably go higher with beefier transistors.
The circuit resonates at the LC frequency automatically. A problem was making this easily adjustable so that I could use the oscillator as the VFO stage in the Phase Locked Loop.
Usually only the C variable in the LC circuit is varied, but with a saturable reactor as the L portion, you can now vary the inductance and hence the frequency, with voltage, making it easy to integrate into a PLL.
I'm quite excited about this, I really needed the PLL to keep the other two oscillators locked on, 120 degrees out of phase.
So it _should_ be stable, especially if I use an external stable reference oscillator with minimal drift, PLL the primary LC oscillator off that, and PLL the other two off the primary.
So then I run the three phases through a decoupling capacitor, add in the HV biasing current, and viola, a 1kv DC offset 1kv sine wave. The AC reactance at high frequency limits the RF current, and the DC resistance of the wire limits the bias current, Im using 44 AWG wire (and it was a huge pain to wind, even with a coil winder!)
Im still running a SEP around each coil, just in case it's needed.
Doing it this way, keeps the components fairly generic and easy to come across, even if it's a bit more complicated than a pulsing setup...