You can change the centre frequency by right-clicking on the large round arrows in the frequency bar.
If you change band or centre frequency it affects all users on that device.
SDR Device 1: RTL-SDR Blog V3.
SDR Device 2: RTL-SDR Blog V3. Antenna: 6m 2 element Horizontal yagi pointing South East.
SDR Device 3: SDR Play RSP1.
SDR Device 4: SDR Play RSP1A. Antenna: 20m/14Mhz Inverted V dipole.