priyom.org

S21

Enigma ID S21
Name Russian Man 0 0 0
Frequencies 3323, 3823, 4454, 4854, 4973, 5373
Status Inactive
Voice Male, automated (the same as S06)
Emission mode USB + carrier
Location Russia

Russian

Activity pages

S21 is believed to have transmitted from Russian naval base in Kaliningrad. The language was Russian. It initially utilized a female voice, with the final figures in groups inflected, but starting in October 2010, it used the same voice as S06. Last heard in October 2013.

Transmission format:

Preamble Message Outro
973 760 31 70528 70528 19662 19662 97873 97873 ... 760 31 0 0 0
3-figure transmission ID 3-figure group, purpose unknown Amount of 5-figure groups in the message 5-figure paired groups 3-figure group, purpose unknown Amount of 5-figure groups in the message?  
Repeated for 4 minutes Repeated twice Repeated twice   Repeated twice Repeated twice  

S21 always transmitted 40 minutes after M45, and repeated the same message that M45 transmitted, with a different transmission ID.

S21 used to operate on the following schedule. The transmission ID was taken from the last three digits of the lower simultaneous frequency, so for example a transmission made in January would have the ID "323". The higher simultaneous frequency was always 400 kHz above the lower one.

Day UTC Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Tuesday
Thursday
17:42       4454
4854
4973
5373
4973
5373
4973
5373
4973
5373
4454
4854
4454
4854
   
18:42 3323
3823
3323
3823
4454
4854
              3323
3823
3323
3823

Mistakes were sometimes made, and M45 transmitted on these frequencies instead of S21.

S21 was operated from a computer running Windows XP, as it can be heard by the shutdown sounds here and here.

When female voice was used, the word "Razdel" was present after the amount of 5-figure groups and before the message groups, and after the message groups and before the 3-figure group.