6900 kHz and nearby frequencies are very heavily used by Spanish speaking freebanders, some of which are probably licensed ham operators...some of which are probably not...so use of 6901 kHz is not surprising. The operating habits are similar to 11 meter CB freebanders who work SSB mode above and below the legal CB radio band. I have monitored 6900 kHz LSB extensively and have determined that 6900 LSB is the "calling channel" or home channel for these operators. Often they'll do a call on 6900 and QSY to 6905 or 6895 or 6920 or something like that. I've heard stations coming from North America, South America, Central America and the Caribbean talking to each other on this frequency and nearby. They usually use 5 kHz steps and mostly stick to LSB mode, although I have logged activity on 6900 USB several times...usually when 6900 LSB is busy.