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ARQ6-90 - ARQ6-98 

ARQ 6-90.jpg
Frequencies 10 MHz,23 MHz
Frequency Range 10 MHz - 23 MHz
Mode USB
Modulation FSK
Emission Designator
Bandwidth 700 Hz
Location Worldwide
Short Description ARQ6-90, also known as ARQ-6-90 and ARQ-6/90, is a 6-character block simplex ARQ system formerly used by French and Italian diplomatic services exchange of teletype-data. It is no longer used or seen today.
I/Q Raw Recording
Audio Sample

ARQ6-90 is a 6-character block simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system formerly used by French and Italian diplomatic services. It is no longer used or seen today. This mode is very similar to SITOR, and uses the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-476 charset.

ARQ6-90 and ARQ6-98 differ in both bandwidth and their inter datablock timing. A complete cycle for ARQ6-90 has duration of 450 msmilliseconds (.001 of a second) of which the data block is 210 msmilliseconds (.001 of a second) an interval is 230 msmilliseconds (.001 of a second).


A log from 1994:

---------  -------  ----------  ---------  -------------------- 
 10180.43  ARQ6/90  200/300                5 LG'S, NO ID 
 14531.36  ARQ6/90  200/258                5 LG'S, FF 
                                           DIPLOMATIC MSGS. 
 15801.44  ARQ6/90  200/230     "FDFE"???  MSG. FROM 
                                           "MINDEFENSE PARIS" , 
                                           DIPLOMATIC MSG TO 
 17454.50  ARQ6/90  200/200     "FDEFE"    5LG'S, FF. 
                                           MSG.,DIPLOMATIC MSG. 
                                           "RIO DE JANEIRO" 
                                           RESULTS OF ELECTIONS 
                                           IN BRAZIL. 
 18033.50  ARQ6/90  200/450     "RFGW"     FF MSG. AND 5LG'S . 
                                           FF EMB IN COLUMBIA 
                                           TO PARIS 
 18450.36  ARQ6/90  200/170                5 LG'S AND FF MSG. 
                                           TO LIMA 
 18487.75  ARQ6/90  200/300 
 19763.82  ARQ6/90  200/170                FF MSG ABOUT 
                                           AMBASSADORS, ETC. 
                                           "RETAIRE DE 
                                           L'AMBASSADE DE 
 19931.83  ARQ6/90  200/170     "RFGW"     5LG'S 
 20838.00  ARQ6/90  200/350                RXReceive. IDLE ONLY 
 21854.81  ARQ6/90  200/237                FF MSG., PARIS 
                                           HEADINGS, "AGER DERA 
                                           785", 5LG'S 
 21867.82  ARQ6/90  200/300 
 21927.00  ARQ6/90  200/200     ?          all encrypted except 
                                           for "QRU" at end 
 22853.80  ARQ6/90  200/396     "RFGW"     MFA PARIS. FF MSG. 
                                           ABOUT MINISTER OF 
 22879.80  ARQ6/90  200/193                5LG'S AND FF. MSG. 
 22959.77  ARQ6/90  200/300     "BRSL"     FF MSG. AND 5LG'S . 
                                           MOST PROBABLY "RFGW" 
 22979.88  ARQ6/90  200/170                FF MSG., 

Decoding Software[edit]

Professional Equipment/Software

Video Examples[edit]

Analysis and decoding of an ARQ 6/90 signal (old mode used by the French armed forces).

Additional Links[edit]

Additional Images[edit]