A form for a tuning inductor used in the output filter of a two vacuum tube ham radio transmitter

thingiverse

Making this radio calls for a classic air wound coil utilizing 20 gauge wire with an incredible spacing of 16 turns per inch. My experience with creating stable coils tells me that maintaining rigid spacing is often challenging. This led me to brainstorm applying screw threading directly onto the coil form, thus creating a stable framework that would securely hold each turn in place. Taking this idea a step further allowed for mounting locations to be added, which ensures easy securing of the coil within the radio's enclosure. A significant design aspect I incorporated is a narrow ridge allowing users to attach small microclips anywhere along the coil's length for fine-tuning its inductance level. Considering individual users will have varying inductor needs, I've also included OpenSCAD source files enabling users to craft custom-designed coil forms that cater precisely to their specifications.