RF-Toroid was written as a supplement to the Micrometals RF Application catalog.
Much emphasis was put into calculating the location of the Self resonate frequencies for series and shunt inductors. RF-Toroid is for use DC to 300 MHz. Much research went in to the calculation and corrections from the standard formulas for low perm phenolic cores to better predict the RF style of winding and application.

Some features include:
1) SRF for series and shunt cores, peak Q curve ranges and 200 360 degree coverage to achieve the best product possible for the microwave designer who needs accurate and abundant information at the finger tips to compare one core to another simultaneously.

2) The custom core feature allows for custom shaped cores, stacking cores side by side , ferrite cores and machining custom phenolic cores from plastic, wood, etc...