• Country
• United States of America (USA)

• Manufacturer / Brand
• MILITARY U.S. (different makers for same model)

• Year
• 1978

• Category
• Military Equipment (not Re, Tr or RXT)

• Radiomuseum.org ID
• 206272

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Transistors
• 8

• Semiconductors

• Main principle
• none

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 115/230 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: Differential Voltmeter AN/USM-381 - MILITARY U.S. different makers

• Shape
• Boatanchor (heavy military or commercial set >20 kg).

• Dimensions (WHD)
• 17 x 11.75 x 10.4 inch / 432 x 298 x 264 mm

• Notes
• Unit in pictures is manufactured by the Aul Instrument Corporation. Differential voltmeter AN/USM-381 is an all solid state 0.005 percent dc differential voltmeter operating over the range from 0 to 1100 volts dc, with a maximum null sensitivity of 100 microvolts full scale right or left deflection. An internal precision 1100 vdc reference supply and a Kelvin-Varley type voltage divider is used in conjunction with a chopper stabilized null detector to measure unknown voltages over the entire range from 0 to 1100 volts. The equipment is also capable of operating in a direct-reading mode with 3 percent full-scale accuracy over the range of 0 to 1100 volts dc. The equipment incorporates extreme isolation between the inner chassis and outer combination case so that either the high or low side of the voltmeter input may be at a common mode voltage potential of 5000 vdc from case ground potential. A separate input is provided to allow measurement of voltages up to 15,000 vdc with 0.05 percent accuracy with a minimum input resistance of 100 megohms.

• Net weight (2.2 lb = 1 kg)
• 29.25 lb (29 lb 4 oz) / 13.280 kg

• Author
• Model page created by Hank Kaczmarski. See "Data change" for further contributors.

• Other Models

• Here you find 399 models, 351 with images and 210 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from MILITARY U.S. (different makers for same model)