The OEP variable inductor offers truly continuous variation in inductance throughout its range: Literally any inductance between 0 and maximum (typically 28 uH) can be obtained, with a practical working resolution of .01 uH.

Newly redesigned, the current version of the variable inductor makes use of all we’ve learned about RF design to deliver high-amperage performance superior to any inductor we’ve offered in the past. The new R128C is completely non-magnetic, and all materials are chosen for high electrical and thermal conductivity and low loss in RF fields. The plated #10 copper bus wire rests in a precision-machined helical groove cut into a glass-based phenolic tubular core. This core turns on two large sealed stainless steel ABEC-5 instrument bearings seated in machined Ultem frames. Incorporated into the design are two of the RF-proven high-amperage rotary contacts originally designed for high-end variable capacitors.

The geometry of the design reduces parasitics to levels comparable to those of much smaller and simpler fixed coils, while the size, shape, and composition of conductive subcomponents allows high-amperage performance comparable to that of much larger tubular inductors.