544-B

The General Radio 544-B Megohm Bridge was introduced in Catalog K1 (1939) and remained available through Catalog R (1963), after which it was replaced by the 1644-A.

The Type 544-B Megohm Bridge is a null instrument using a Wheatstone bridge circuit. It uses a built-in vacuum tube voltmeter (VTVM) as a detector, and an AC power supply 544-P3 for both VTVM and the Unknown voltages.

The 544-B comes installed in an oak hardwood case with operating instructions attached to the inside of its cover. A flexible jack with lead is mounted in the cover for checking the internal standards as explained in the manual. The 544-B was also available modified for use with a battery power supply.

Specifications

• Range: 0.1 MΩ to 1,000,000 MΩ
• Accuracy: ±3% on the 0.1, 1, and 10 multipliers; ±4% on the 100 and 1000 multipliers
• Output Voltage AC Supply: 100 V or 500 V, jumper-selectable
• Short Circuit Current AC Supply: 12 mA

Links

• Experimenter describing Type 544-B July 1937
• Experimenter describing Type 544-B June 1939
• Experimenter describing Type 544-B February 1940

Photos

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