An automatic filter adjusting apparatus for adjusting an adjustable filter (34) having an input and an output. The apparatus includes a reference signal provider (32) for providing an FM signal to the filter (34), an adjusting signal generator (45, 44, 35) for providing an adjusting signal to the filter (34), a comparator (40) for comparing the output of the filter (34) to a reference level and a controller (41, 42, 43) responsive to the comparator (40) for controlling the adjusting signal generator (45, 44, 35).