The final crew schedule for the week of Aug 3-9 was released recently and it showed a MAI-75 activity scheduled for Aug 4 and 5. This is soon after the Space X Demo-2 undock so changes to that event could impact the schedule.
The current dates and times of the activity are as follows:
Aug 4 (12:25-18:10 UTC) is setup and day 1 operations.
Aug 5 (11:15-18:45 UTC) is day 2 operations and close out.
This is the Moscow Aviation Institute SSTV experiment that is activate for orbital passes over Moscow, Russia. It has traditional been PD-180 or PD-120 and transmitting on 145.800 MHz.