UNID 13528.1 kHz CW 00:20 UTC 05 AUGUST 202200:20 UTC - UNID CW beacon; weak barely readable. Sound like it is transmitting "6" (- . . . . ).
Sources indicate that 13528.1 kHz should be "A" and originating from Russia.
Letter Beaconhttps://en.wikipedia.org/wiki/Letter_beacon
RSPduo | End-fed longwire antenna