The 4K1 prefix was allocated to all USSR Antarctic stations from January, 1973 (tnx DXNS #560), and this continued until late 1994.
However, 4K1G was used from 1971.
Each USSR base was allocated it's own 4K1x callsign, as follows:
| Callsign | Base | DXCC | CQ Zone | IOTA | Note (click on callsign dates to see QSL and QRV dates) |
|---|---|---|---|---|---|
| 4K1A | Molodezhnaya | Antarctica | 39 | AN-016 | |
| 4K1B | Mirny | Antarctica | 29 | AN-016 | |
| 4K1C | Vostok | Antarctica | 29 | AN-016 | |
| 4K1D | Novolzarevskaya | Antarctica | 38 | AN-016 | |
| 4K1E | Komsomolskaya | Antarctica | 29 | AN-016 | QSL required |
| 4K1F | Bellingshhausen | South Shetland Is | 13 | AN-010 | |
| 4K1G | Leningradskaya | Antarctica | 30 | AN-016 | |
| 4K1H | Russkaya | Antarctica | 32 | AN-016 | |
| 4K1J | Druzhnaya | Antarctica | 13 | AN-016 | 1984-92 |
| 4K1J | Novolazarevskaya | Antarctica | 38 | AN-016 | March 1992. QSL required |
| 4K1K | Komsomolskaya | Antarctica | 29 | AN-016 | |
| 4K1L | Pionerskaya | Antarctica | 29 | AN-016 | |
| 4K1R | Moldezhnaya | Antarctica | 39 | AN-016 | QSL required. DXNS #743 - QRV for DOSAAF-50, 1976 |
Many 4K1xx and 4K1xxx callsigns were also issued. These are listed here .
The first personal callsigns seem to have been issued in 1970.