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
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 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 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 with Switch. Marked R.L. 7019 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 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
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 Flameproof Key With Air Ministries Marking
Inside the Air Ministries Key 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 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 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 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 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 Marconi 365-Style Key by Redifon
Another Marconi 365-Style Key Another View of the Marconi 365-Style Key Key Used by NATO Forces Inside the NATO Key
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 Close-Up of the Key SR-Cotel Radio Key by Jack Sykes, G3SRK Key From Clansman Wireless Set. Ca. 1980





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