The quadrature detector on your imager has a reference signal of 63.85 MHz coming into one of the channels. The signal channel has a signal of 63.86 MHz coming into it. What frequency or frequencies will be coming out of the detector?
The DBM within the quadrature detector produces frequencies at (n - no) and (n + no).
The filter within the quadrature detector removes (n + no).
n = 63.86 MHz, and no = 63.85 MHz.
Therefore, (n - no) = 10 kHz.