4260A Universal Bridge

The 4260A is a resistance, capacitance, and inductance bridge. Its measurement frequency is fixed at 1kHz, but it provides a rear-panel connector to facilitate the use of an external oscillator, ranging from 20Hz to 20kHz. There is also a rear-panel connector for an external detector.

It has a unitless, center-reading null meter with adjustable sensitivity. Its manual range selection switch implements a clever mechanism which rotates schematic symbols (capacitor and resistor in parallel, etc) engraved on a disk into view behind a small window on the front panel. Its main nulling adjustment features arrow-shaped neon indicators for increase and decrease, along with a turns counter dial with neon lamps to represent the decimal point.