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:

CallsignBaseDXCCCQ ZoneIOTANote (click on callsign dates to see QSL and QRV dates)
4K1A
MolodezhnayaAntarctica39AN-016 
4K1B
MirnyAntarctica29AN-016 
4K1C
VostokAntarctica29AN-016 
4K1D
NovolzarevskayaAntarctica38AN-016 
4K1EKomsomolskayaAntarctica29AN-016 QSL required
4K1F
Bellingshhausen South Shetland Is13AN-010 
4K1G
Leningradskaya Antarctica30AN-016  
4K1H
Russkaya Antarctica32AN-016 
4K1J
Druzhnaya Antarctica13AN-0161984-92
4K1JNovolazarevskayaAntarctica38AN-016 March 1992. QSL required
4K1K
Komsomolskaya Antarctica29AN-016 
4K1L
Pionerskaya Antarctica29AN-016 
4K1RMoldezhnaya Antarctica39AN-016QSL 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.