An exemplary adjustable steering column comprises a gear positioned and configured to cause a shaft to rotate about its central axis as the steering column telescopes. Each FAP is independently registered with a core network and provisioned with a location area code common to each FAP. In one embodiment, a method determines a plurality of weak ETF’s, which are strongly tolerant of errors, and determines a plurality of strong ETF’s therefrom, which are less tolerant of errors. Stable operation is provided over a large range of operating emission currents, up to a 6:1 ratio, and this HCA can emit electron currents of up to 30 Amperes in magnitude to an external anode that simulates the current drawn to a space plasma, at voltages of less than 20 Volts. In addition, the mop block structure may include rails that mate with teeth located on the hinged connector to give additional stability to the enhanced sponge mop.