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Equipment file · Triode vacuum tube (telephone repeater)

101-B repeater tube

Western Electric · c. 1915–1918

Evidence status · documented

Identity and core specifications are documented; some historical fields remain unavailable.

The Western Electric 101-B was a filamentary triode built for telephone repeater service where only modest output power was needed. It descended from the 101-A and ran from a 4-volt battery filament supply.

Introduced
c. 1915–1918
Category
Triode vacuum tube (telephone repeater)
Intended use
Amplification in telephone line repeaters
Production
Western Electric, for Bell System long-distance repeaters

Why it mattered

  1. 01

    As a 'repeater bulb' it helped the Bell System amplify voices over long-distance lines.

  2. 02

    Tubes of this family set engineering practice for triode audio amplification that fed directly into Western Electric's public-address amplifiers.

Engineering record

Filament rating
4 V, 1.25 A, direct battery supply[1]
Function
A repeater bulb with lower output impedance, suited to power amplification in telephone circuits[1]

Original pricing

No reliable period price located

2026 equivalent

Not calculated without a reliable original price.

Public price evidence was not sufficient to publish a defensible original figure.

Use in the field

No named deployment could be tied to this exact item by a checked source yet. Know of one? Suggest it on the contribute page.

Manuals & original documents

No authoritative manual or original document has been located for this profile.

Sources

  1. 1101B Western tube entryRadiomuseum.org · reference

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