IET 1490D Overview
The General Radio Model 1490D Decade Inductor is an assembly of four 940 Decade-Inductor Units in a single metal cabinet. The units have no electrical connection to the panel, but a separate ground terminal is provided, which can be connected to the adjacent low terminal, leading to the smallest decade. Total inductance of 11.11 H in 0.001 H steps Four decades High Q or 200 and above and a maximum voltage of 500 Vrms.