A radio device requires a tunable transceiver such that the transceiver can
be accurately set to a desired frequency. When a signal with known
frequency accuracy is being received, an offset detector can determine the
frequency offset generated by the transceiver due to improper tuning. An
automatic frequency control (AFC) system (100) is comprised of a tunable
transceiver, an offset detector (103) and an AFC control processor (105)
for utilizing information from the offset detector to reduce the
inaccuracy in frequency by tuning the transceiver towards the received
signal frequency. The AFC control processor (105) utilizes one of more
threshold levels for defining a maximum correction threshold (311) based
upon the desired maximum offset correction. These thresholds are used by
the AFC control processor (105) to efficiently control the predetermined
frequency range of the tunable transceiver (101) for most efficient
operation.