Roy's tube radio pages

Hewlett Packard 410B Vacuum Tube Voltmeter

The advertised uses of the 410B were audio, rf and vhf measurements, dc voltage and resistance measurements.
 
Frequency range: 20Hz to 700MHz
 
Voltage range: 0.1 to 300v, in 7 ranges
 
Input impedance: 10meg, 1.5pF shunt
 
In 1955 the list price was $245, making it an expensive instrument. Today you can buy them at online auctions for $20 or $30, about the same price as people pay for simple vtvm's which in the 50's sold for $50. But, do not buy one without the probes, and the tube which goes in the ac probe. These 2-01C tubes are currently selling for about $50.
 
The tubes used in the unit are:
  • V1: 2-01C, or EA53, in the ac probe.
  • V2 and V3: 12AU7 in the dc amplifier and meter bridge circuit.
  • V4: OB2 voltage regulator.
  • V5: 6X4 rectifier.
  • V6: 6-4 ballast tube.
HP 410B Voltmeter
| back to older test equipment |