Single-letter beacons
The Russian naval bases broadcast single-letter beacons to help ships find the best communication channel given the current conditions. The beacons are clustered around ten different frequencies in 100 Hz slots. Not all channels are active at a given time.
| Marker | D Sevastopol |
P Kaliningrad |
S Severomorsk |
C Moscow |
A Astrakhan |
F Vladivostok |
K Petropavlovsk- -Kamchatsky |
M Magadan |
|---|---|---|---|---|---|---|---|---|
| Frequency | 3594.7 | 3594.8 | 3594.9 | 3595.0 | 3595.1 | 3595.2 | 3595.3 | 3595.4 |
| 4557.7 | 4557.8 | 4557.9 | 4558.0 | 4558.1 | 4558.2 | 4558.3 | 4558.4 | |
| 5153.7 | 5153.8 | 5153.9 | 5154.0 | 5154.1 | 5154.2 | 5154.3 | 5154.4 | |
| 7508.7 | 7508.8 | 7508.9 | 7509.0 | 7509.1 | 7039.2 | 7039.3 | 7039.4 | |
| 8494.7 | 8494.8 | 8494.9 | 8495.0 | 8495.1 | 8495.2 | 8495.3 | 8495.4 | |
| 10871.7 | 10871.8 | 10871.9 | 10872.0 | 10872.1 | 10872.2 | 10872.3 | 10872.4 | |
| 13527.7 | 13527.8 | 13527.9 | 13528.0 | 13528.1 | 13528.2 | 13528.3 | 13528.4 | |
| 16331.7 | 16331.8 | 16331.9 | 16332.0 | 16332.1 | 16332.2 | 16332.3 | 16332.4 | |
| 20047.7 | 20047.8 | 20047.9 | 20048.0 | 20048.1 | 20048.2 | 20048.3 | 20048.4 |
Sample of the markers D, P, S, C, F and K heard around 16332 kHz on 3 June 2015: