just leave it alone and go into another room to test, or at least a couple of feet.
450.0000 to 469.9875 NFM 12.5 UHF Standard Band
so 12.5 is the right step.
Or, just program the 22 channels into your scanner and let it find the FRS/GMRS radios. With so few channels, it should do it pretty quick, and you won't need to be so close to the users.