• Country
• United States of America (USA)

• Manufacturer / Brand
• Hewlett-Packard, (HP); Palo Alto, CA

• Year
• 1949 ?

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 225419

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

• Main principle
• none

• Wave bands
• - without

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

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: Vacuum Tube Voltmeter 400C - Hewlett-Packard, HP; Palo Alto

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 7.5 x 8.5 x 9.5 inch / 191 x 216 x 241 mm

• Notes

• Voltage Range:
  12 ranges, selected on front panel switch. Full scale readings of:
  0.001 V, 0.1V, 10V
  0.003 V,  0.3 V,  30.0 V
  0.01 V,  1.00 V,  100 V
  0.03 V.  3.00  V, 300 V
  
  Frequency Range: 20 cps to 2 mc.

  Accuracy:
  The over-all accuracy of the meter is within ±3%  below 100 kc and ±5% from 100 kc to 2 mc. Line voltage variations from 105 to 125 volts or changing tubes will affect the reading by less than  3% at all frequencies
  below 100 kc.
  
  Calibration:
  Calibrated to read rms value of sine wave. Voltage indication proportional to average value of full sine wave. Linear voltage scale with db calibration from -12% +2 dbm. 10 db intervals between voltage ranges.

  Input Impedance: 10 megohms shunted by 15 µµf on
  ranges 1.0 V to 300 V; 24 µµf on ranges 0.001 V  to 0.3 V.
  
  Output Circuit: Maximum output 0.5 V corresponding to full scale deflection of meter. Internal impedance 1,000 ohms. Gain 500 when instrument is on the 0.001 volt range.

• Net weight (2.2 lb = 1 kg)
• 15 lb 0 oz (15 lb) / 6.810 kg

• Source of data
• -- Original prospect or advert

• Author
• Model page created by Pius Steiner. See "Data change" for further contributors.

• Other Models

• Here you find 392 models, 360 with images and 138 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Hewlett-Packard, (HP); Palo Alto, CA