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 Another Early British Camelback Key of Similar Design to the GPO 187 Key
Stroh Double-Current Key, Patented 1868 Top View of the Stroh Key. The Lever Pivots Sideways to Change Between Send & Receive 6-Terminal Double Current Reversing Key by Warden & Co. (Varley Patent of 1858) Westminster, England Another Varley Patent Key
Postal Key Made By Siemens Brothers & Co. Ca. 1880 Another View of the Siemens Brothers Key Showing the Name 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 Without the Glass Cover. Gent & Co. Ltd. Another View of the Gent & Co. Double Current Key GPO Type 562
British Railway Block Bell & Key. Used for Sending Signals Between Switch Towers. These Sets were NOT used to Send Morse Code Inside the Block Bell Instrument. These Instruments Were Used to Send Codes to Indicate the Status of Trains Occupying Different Sections of Track Close-Up of the Signalling Bell. For More Information About Block Bell Instruments, Check Out My Page on Needle Telegraph & Block Signalling Typical GPO Postal Key
Another View of the GPO Postal Key GPO Type 2036 GPO Type 3092 Single Current Key by Elliott Brother, London
Another View of the Elliott Brothers Key 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) Another PATT 1056 Key. This One is Made by Baird & Tatlock Admiralty Telegraph School Training Key
Another View of the Admiralty Training Key Possibly British Key Marked "Marshall Key". Maker Unknown Ediswan Key & Buzzer Set Ediswan Set With Buzzer Cover Removed
A Key & Buzzer Set by Walters Electrical, London. 1917 The Key & Buzzer Set Includes a French Made Microphone and Earpiece so the Set Can be Used Like a Telephone The Walters Key & Buzzer Set With the Cover Removed to Show the Buzzer 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 with Switch. Marked R.L. 7019 Postal Style Key by Charles Palmer
Close-up of the Palmer Name A Railroad Signal Block Key. Not Used for Sending Morse (See Page on British Needle Telegraph) Close-Up of the Railroad Signal Block Key Morse Training Key by WG Pye & Co, Cambridge
Top View of the Pye Key The Victory Key. Used for Code Practice. Post-WW1 Close-up of the Victory 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 A Key, Buzzer, and Light Set by Lowdon Scientific Instrument Co.
Close-Up of the Lowdon Instrument Co. Components Close-Up of the Lowdon Nameplate Walters Electrical Postal Key With Slot for Bug Wedge Another Postal Style Key by Walters Electrical
Close-Up of the Walters Nameplate A Third Postal Style Key by Walters Electrical British Postal Style Key With and Unusual Pivot Frame Another View of the Unusual Pivot
RAF Airplane Key With Winker Lamp (F9WT Collection) Postal Key by Pye & Co. Another Pye & Co Key Postal Style Key by Signalling Equipment Ltd. Ca. 1940's
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 Flameproof Key With Air Ministries Marking
Inside the Air Ministries Key Key From Fullerphone MKIII Field Telegraph Set A Different Version of the Fullerphone MKIII Key With a Longer Lever Key From Fullerphone MKV Field Telegraph Set (F9WT Collection)
British "Bathtub" Key Used on the Lancaster Bomber Inside the Bathtub Key Small British Key with Large Contacts. Maker Unknown Top View of the Small British Key
Unknown Small Key Possibly Part of a Field Transmitter Set Another Similar Field Set 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 The Admiralty Pattern Type 7681 With Optional Cover British Military WT-8Amp Key Another Style of the WT-8Amp
A WT-8Amp Key Made by JH Bunnell, NY Another WT-8Amp Key. This One Was Made by the Canadian Company, Westclox British Spitfire Fighter Plane Landing Light Key British Aircraft Spark Key. Has a Gasket Around the Lever to Make it Flameproof. Made by Lucas Ltd. in Birmingham England
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 Practice Key by The Dulci Co. London
Another View of the Dulci Key Miniature Key Used in British SOE Type B2 Spy Set Close-Up of the SOE Spy Key Mini Key Used With Lifeboat Transmitter
Unknown Key Possibly Used in Shipboard Wireless Another View of the Shipboard Key Walters Model 5KK Mounted on Tuner Box The Walters 5KK With Cover Removed
Marconi Type 316A (F9WT Collection) 316A Key With Cover Removed Marconi Type 971 Inside the Type 971 Key
Marconi Marine Type 1588. Used With Marconi AD107 Transmitter A Sideswiper Style Key Made by Marconi Wireless for the British Diplomatic Services Unknown Key Stamped GB-1091 Marconi Marine 365-FZ
Inside the Marconi Marine 365-FZ The Marconi 365-FZ Label Marconi Marine Key Used With Salvor Emergency Lifeboat Transmitter Side View of the Salvor Key
Key Used by the British SAS (Special Air Service) The British SAS Key With the Cover Removed Unknown British Key in Metal Box. Possibly Made by Marconi Wireless or Marconi Marine The Same Key With the Metal Cover Removed
Unknown Key With a Send/Receive Switch. Possibly Made by Marconi Wireless Marconi 365-Style Key by Redifon The Redifon Key With the Cover Removed Another Marconi 365-Style Key
Another View of the Marconi 365-Style Key Key Used by NATO Forces Inside the NATO Key Marconi Marine Z-50
Marconi Marine Z-50 With Cover Removed Close-Up of the Z-50 Nameplate British NATO Type Mk3 Another View of the NATO Mk3 Key
ITT Marine Key Inside the ITT Marine Key Small British Military Key With Leg Strap. Used With the Racal PRC-320 HF Radio Close-Up of the Key
  SR-Cotel Radio Key by Jack Sykes, G3SRK Key From Clansman Wireless Set. Ca. 1980  





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