Equipment file · Mica-diaphragm headset receiver

Mica-diaphragm receiver

Nathaniel Baldwin · 1910

Evidence status · documented

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

Utah inventor Nathaniel Baldwin patented a highly sensitive telephone receiver in 1910 (US 957,403), intended for telegraphone, acousticon, wireless-telephone and sound-amplifier use. His hand-built receivers exceeded the Navy's sensitivity standards and were supplied to it during the First World War.

Introduced
1910
Category
Mica-diaphragm headset receiver
Intended use
Sensitive receiver for telephone, wireless telephone and sound-amplifier use
Production
Hand-built by Nathaniel Baldwin, later supplied on contract to the US Navy

Equipment photographs · 1

US patent 957,403 (1910): telephone receiver

1 / 1 · US patent 957,403 (1910): telephone receiver

US patent 957,403 (1910): telephone receiver·Nathaniel Baldwin·Public domain (US patent)

Why it mattered

  1. 01

    Its sensitivity made it the preferred headset of US Navy wireless operators in the WWI era.

  2. 02

    Baldwin's company went on to make loudspeaker and headset drivers for the early radio industry.

Engineering record

Patented design
US 957,403 (filed July 1909, granted May 1910): a single spool winding giving the combined magnetic action of four pole pieces[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

Adopted by the US Navy for wireless-telephone headsets during the First World War[2]

Manuals & original documents

Sources

  1. 1US957403A - Telephone-receiverGoogle Patents · patent · 1910
  2. 2Nathaniel Baldwin, Utah Inventor and Patron of the Fundamentalist MovementUtah Historical Quarterly · reference

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