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
|
| 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.