Both 6830 USB and 6840 USB have the same signal strength (peaking at S2-S3) with usual freebander-level audio quality. 6840 is considerably more busy than 6830, perhaps indicating that some stations QSYed from 6840 kHz to 6830 kHz for a "private" QSO and then went QRT or switched back up their original frequency.
"0104" heard as an identifier of some kind