Spokesman Ordinary pipeline helical filter Mystery delay tar
Helical Filters
Filters for RadioJove
I made and tuned a helical band-pass filter! [Details in the comments] : r/amateurradio
Helical resonator filters with improved multipactor performance exploiting rigorous modelling and the large gap approach - Salza - 2019 - IET Microwaves, Antennas & Propagation - Wiley Online Library
Professional on Custom Helical 5G RF Bandpass Filter, Tunable Bandpass Filter Designing and Manufacturing by Temwell Corporation
Helical resonator filters with improved multipactor performance exploiting rigorous modelling and the large gap approach - Salza - 2019 - IET Microwaves, Antennas & Propagation - Wiley Online Library