"I ended up printing a two-wall cylinder (could be a single wall) vertically for the core and then an array of spacer-washers flat. The washers were pressed onto the core and the layer lines on both create a nice ratcheting friction. I added little 45 degree notches to each washer to give the wire at the top of a section winding to be able to return to the base of the next section with at least a little separation from the subsequent layers." - pitts8rh
Ah, as usual, you're way ahead of me! Makes total sense...
"None of these coils will compete with your large air-core coils for SRF and Q, but I'm not sure that you need or even want 300+ volts on the antennas?"
High voltage! (Done dirt cheap).
But actually, yes, it could be a huge liability come compliance time (where products go to die just as they cross the finish line). I keep trying to think of ways to reduce the voltage and spread the spectrum, but phase detection via digital means is the rub. Maybe don't phase lock, just stimulate a low Q (RL) tank with an octave's worth of pseudo noise and count periods or something. What I really want is shielding to make the C field more directional and kill half the intrinsic.