CSP-1750 and CSP-1756
CSP-1756, Photo Copyright © 2007, Richard Brisson. Used with permission.
DESCRIPTION OF CSP-1750, Call Sign CipherCSP-1750 is a call sign cipher used to encrypt the call signs and addressgroups used on radio circuits.
CSP-1750 is a little box, roughly 4"x2"x10" on a wire frame that tiltedit up to 45 degrees. There are four columns with chains behind the columns.The columns are labeled with A-Z,/,0-9. A metal stick is inserted at theletter and it catches the internal chains. The stick is then pulled downand at the bottom of each column is a window that displays a number between00 and 36. The four chains are pulled down 4 times and the values in thewindows are then used to look up the resulting call sign in a book.
The knob on the left is used to "zeroize" or reset the device. The clipson the right are used to hold the stylus.
Please see the Operation Instructions forCSP-1750 and CSP-1756 for detailed information on these devices.
REFERENCES:Instructions for Penelope Cryptosystem, Operationand Maintenance of CSP-1750 (KA-2) and CSP-1756 (KA-3), AMSP 295(B),February 1965.
Return to the ECM Mark II page.