Katok-65
From HFUnderground
Katok-65 is the callsign for a Russian military communication station. It is very active during Russian military exercises, most notably ZAPAD. Katok-65 is the recipient callsign of messages sent on this network; it wouldn't indicate the name of the station itself sending on it. Messages addressed to Katok-65 also rarely appeared on the main district network, on the channel 4625 kHz, UVB-76 (The Buzzer).
This network also formerly used 6930 kHz for daytime frequency, before it switched to 4224 kHz.
SPECIFICS
Katok-65 (recipient callsign)
Frequencies: 3218.5 kHz (nighttime), 4224 kHz (daytime)
Status: Active
Voice: Live Russian
Emission mode: USB
Location: Russia
(Information courtesy of Priyom.org)