Precision Short-Circuit Termination
Short-circuit terminations are useful in establishing initial conditions of line length and signal phase in, for example, impedance measurements. An s-c termination consists of a precision-machined, silver-plated disk, mounted in a centering gear ring and locking-nut assembly, to produce a fixed short circuit. The 900-WNC, -WNE, and -WN4 each includes a support for one end of the inner conductor of a 900-LZ Reference Air Line, which is beadless.
Part marked as 4-AO, which we estimate to be an equivalent to General Radio Part #: 900-WN4
General Radio Part #: 900-WN4 (with support, plane at 4 cm)
Sourced from military surplus lots.