S13 is the same type of counting station as S14 but given a different ID since it used different callsigns. It’s most likely a Russian military test station. The station counts from 0-9 for short periods of time (usually 2 minutes), and uses a live operator. It would also read occasional announcements for callsign UPT76 and others.
Nickname: Russian Counting
Emission mode: USB
Voice Summary: Male and female, live announcer reading off numbers and announcements
Believed Country of Origin: Russia
ENIGMA Active Stations List V1.3
The Conet Project