EICO Series-Parallel R-C Combination Box Model 1140

Circa Early1950's to Late 1960's

An electronic test instrument that combines the functions of a resistance substitution box and a capacitance substitution box into a single unit.

Use Case:

The primary function of this device is component substitution during electronic troubleshooting and design.

• Troubleshooting: It allows a technician to temporarily replace a suspected faulty resistor or capacitor in a circuit to see if the device begins functioning correctly again.

• Circuit Design: Designers use it to "dial in" the optimal resistance or capacitance value for a specific circuit function before soldering a permanent component in place.

• Versatility: It offers over 1,350 combinations, allowing users to select resistors alone, capacitors alone, or both in series or parallel.

Historical Significance:

The EICO 1140 represents a significant era in electronics history where "kit-building" was a popular and accessible way for hobbyists and professionals to acquire high-quality test equipment. EICO was at one point the world's largest producer of electronic kits. These boxes were staples on technician workbenches during the transition from vacuum tube technology to early solid-state electronics.

(H-13.5cm x W-17.5cm x D-7cm)