US Navy Keys
US Navy High Speed Morse Code Certificate
Requirements: Send & Receive CW at 30wpm. This probally is among the last certificates issued. In the late 6Ø's CW had all but been replaced by on-line crypto equipment for both RTTY and Voice operations. In the 7Ø's the Navy suspended teaching Morse Code at The Radioman "A" School. Greg also received a Vibroplex with the certificate

Royal Navy ARS morse code Certificate of Proficiency

Navy MARS Call - NØZMC

Once I Was a Navyman

Manufacturers Codes - 1915 to early 193Øs
Listings from
CA American Radio Research Corp. CABBaldwin Telephone Co.
CACCentral Telephone Co. CADDomestic Manufacturing Engineering Co.
CAECutler Hammer Manufacturing Co. CAFJohn Firth
CAGGeneral Radio CAHCutter Manufacturing Co.
CAJHoltzer Manufacturing Co. CAKWilliam J. Murdock
CALLocke Insulator Co. CAMManhattan Electrical Supply Co.
CANSagame Electric Co. CAOWard Leonard Co.
CAPFrank B. Perry CAQRobbins and Meyers
CARRoller Smith CASChloride of Silver Co.
CATAmerican Transformer Co. CAUTriumph Electric Co.
CAWC. & C. Electric Co. CAXMetropolitan Electric Co.
CAVIndustrial Controller Co. CAYWest Electric Controller Co
CB Crocker Wheeler Co. CD E.J. Simon
CF DeForest Radio Telephone & Telegraph Co. CG General Electric Co.
CH Electrose Insulator Co. CK Kilbourne and Clark
CL Fritz Lowenstein CM Marconi Wireless Telegraph Co. of America
CN National Electric Supply Co CO Copely Manufacturing Co.
CP Cutting and Washington CQ International Radio Telegraph Co.
CR Wireless Specialty Apparatus Co. CS Sperry Manufacturing Co.
CT Federal Telegraph Co. CU Miller Resse Hutchinson
CV Weston Instrument Co. CW Western Electric Co.
CY Wireless Improvement Co. SE Bureau of Steam Engineering, US Navy
Key Designations - XXX-26ØNN - early 193Øs to post W.W.II
CABHSignal Electronic & Mfg. Co. CABJLionel Corp.
CAKUWinslow Co. CAPHTelegraph Apparatus Co. (Ted McElroy)
CAPZTelegraph Apparatus Co. (Ted McElroy) CAQZBrelco
CAY Westinghouse Electric & Mfg. Co. CAZ Brooklyn Metal Stamping Co.
CAZTElectro Specialty Co. CBBXWestern Union Telegraph Co.
CDM D.P. Mossman Co. CEA Bendix
CEJ E.F. Johnson CHD Hardwick-Hindle, Inc.
CJB J.H. Bunnell CJF J.F. Frietz
CJY Leach Brothers CKI Chicago Apparatus Co.
CLR Leach Relay CLS L.S. Brach
CLT Lundquist Tool & Mfg. Co. CMH American Radio Hardware
CMI The Molded Insulator Company CMK McElroy Electronics (Ted McElroy)
CN National Electric Machine Shops Inc. COL Collins Radio Co. Inc.
CRR Bendix CRV RCA Victor, Div of RCA
CSE Signal Electric CTC Chicago Telephone Supply
CTE Telephonics Corp. CUZ United States Telev. Mfg. Co.