POST OFFICE GULSTAD 304 RELAY, 1900's

The Gulstad Relay was invented by K.Gulstad of Copenhagen in 1898

The Relay was used in telegraphy for amplifying the power. The coil is energized by a very small amount of power which activates a contact moving larger locally supplied power.
Post Office Gulstad Relay
This relay is more sensitive to vibrating at high speeds than other P.O. Relays. It achieves this by overcoming delays in movement due to residual magnetism. Up to 200 words per minute is possible using this relay, the average rate of transmission was improved by 50% by fitting these relays on Duplex Systems, see item A0253. Recognised by the letter 'G' or the name itself. Suitable for a single needle telegraph or double plate sounder.
For types of P. O. relays see A0252.

Your comments:

• Not only for increased speed!The relay made it possible to make a lot of the small telegrafstations at the transibiric line unmanned. In stead of having 2-3 telegraph operators living at a station in a deserted area just for re-wiring weak signals, the Gulstad relay did this work alone.
  (As engineer in Great Northern telegraph Co in 1961 - 66 I talked with a pensioned telegraph operator from the line through Russia.)
  .......... Jens Chr. Ledgaard, 3500 Vaerloese, Copenhagen, Denmark, 21st of November 2023
  
  
• Apparently the Gulstad relay was used in double-dotting for increased speed similar to Partial Response signalling used today.
  .......... David Conn, Ottawa, Canada, 21st of September 2011
  
  

A0238