British Keys

Many of the early British telegraph instruments operated on what is called a Double Current Telegraph System.

The US and most of the world used a Single Current system, where current flows only in one direction. A dot or dash is caused by current flowing through the relay, while a space is caused by the absence of a current.

However, in a Double Current system, current flows in one direction through the relays to produce dots and dashes, and flows in the opposite direction to produce spaces. This is accomplished through the use of a Polarized Relay.

Double Current systems are more efficient and can handle higher data rates because the action of changing polarity on the line neutralizes the residual charge on the line when the key is opened. With Single Current systems, this residual charge takes time to dissipate, which limits how fast data can be sent.

Below are some pictures of some interesting keys from Great Britain, including single & double current keys as well as radio keys. Many are stamped "GPO", which stand for General Post Office.

*NOTE: For pictures of British spark keys such as Marconi, please visit my Spark Keys Page.

(Click on each thumbnail to view the full size image):

Early British Camelback Key Marked GPO 187 Another View of the Camelback Key GPO Number Stamp Early Double Current Key by CF Varley
Top View of the Varley Key. The Lever Pivots Sideways to Change Between Send & Receive Classic Style Double Current Key With Glass Cover Double Current Key With Cover Removed Another Double Current Key by H. White, 1917
White Key With Cover Removed Early Double Current Key GPO Type 866 Walters Electrical Type 6K Double Paddle Key. Used for Double Current & Cable Telegraph Double Paddle Key With Glass Cover in Place
Another Early Double Current Key GPO Type 562 Typical GPO Postal Key Another View of the GPO Postal Key
GPO Type 2036 Practice Key by GH Steward, 1898 Another British Practice Key Postal Key by Elliott Brothers
Another Postal Key, Maker Unknown Postal Key Marked "Patt 1056" (F9WT Collection) Ediswan Key & Buzzer Set Ediswan Set With Buzzer Cover Removed
Radio Key by A. Mason, Surrey England Walters Electrical Model 18K Postal Key With Leaf Spring Pivot Different Style Walters 18K With Send-Receive Switch Another Walters Key
Different View of the Walters Key 2 Walters Electrical Keys Walters Electrical Model 20K Postal Style Key by Charles Palmer
Close-up of the Palmer Name Morse Training Key by WG Pye & Co, Cambridge Top View of the Pye Key Unusual Split Lever Key Possibly Made by Siemens, a German Company
Another View of the Split Lever Key Split Frame Key by ATM Top View of the ATM Key Walters Electrical Postal Key With Slot for Bug Wedge
RAF Airplane Key With Winker Lamp (F9WT Collection) Postal Key by Pye & Co. Another Pye & Co Key Unknown Key, Possibly for Wireless Use
Marconi Type PS-213a With Cover Air Ministries RAF Type B Aircraft Key Inside the Type B Key Type B Key Nameplate
RAF Type D Key used at ground stations (F9WT Collection) Inside the Type D Key Small Radio Key, Maker Unknown Key From Fullerphone MKIII Field Telegraph Set
Key From Fullerphone MKV Field Telegraph Set (F9WT Collection) British "Bathtub" Key Used in Lancaster Bomber Inside the Bathtub Key Admiralty Pattern Type 2342
Admiralty Pattern Type 691 Admiralty Type 691 With Cover Removed Admiralty Pattern Type 5475 Admiralty Pattern Type 65485
Admiralty Pattern Type 7681 (F9WT Collection) Close-up of the Type 7681 Name British Military WT-8Amp Key Another Style of the WT-8Amp
British Spitfire Fighter Plane Landing Light Key Shipboard Key With Gasket to Make Key Flameproof Inside the Flameproof Key Marconi Wireless Type 365A
Inside the Marconi 365A Signalling Equipment Ltd. Key Close-up of Label Signalling Equipment Key Used in Double Current Configuration
Unknown Signalling Key Miniature Key Used in British SOE Type B2 Spy Set The Victory Key Used for Code Practice Close-up of the Victory Key
Mini Key Used With Lifeboat Transmitter Unknown Key Possibly Used in Shipboard Wireless Another View of the Shipboard Key Marconi Type 316A (F9WT Collection)
316A Key With Cover Removed Marconi Type 971 Inside the Type 971 Key Marconi Marine Type 1588
Unknown Key Stamped GB-1091 Marconi Marine 365-EZ (F9WT Collection) Inside the Marconi 365-EZ Marconi Marine Key Used With Salvor Emergency Lifeboat Transmitter
 
Side View of the Salvor Key Marconi 365-Style Key by Redifon SR-Cotel Radio Key by Jack Sykes, G3SRK  

 

 

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You can reach me at telegraphdude@comcast.net