The museum is open Fridays through Tuesdays 11 a.m. to 4 p.m. Free timed-entry passes are required. Review our latest visitor safety guidelines.

type 4-D morse telegraph relay

type 4-D morse telegraph relay

Usage conditions apply
Downloads
Description
Telegraph relays amplify an electrical signal in a telegraph line. Telegraph messages travel as a series of electrical pulses through a wire from a transmitter to a receiver. The pulses fade in strength as they travel through the wire, limiting the distance a message can be sent. Relays remedy that problem by detecting a weak signal and automatically re-transmitting that signal down the line using a local power source.
Location
Currently not on view
Object Name
main line relay
relay
telegraph relay
Maker
Western Union Corporation
Measurements
overall: 3 7/8 in x 7 1/4 in x 3 7/8 in; 9.8425 cm x 18.415 cm x 9.8425 cm
ID Number
EM.331922
model number
4-D
collector/donor number
100-848
accession number
294351
catalog number
331922
Credit Line
from Western Union Corporation
See more items in
Work and Industry: Electricity
Communications
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.

Comments

Add a comment about this object