Most LMR radios incorporate an embedded technology that aids the radio in adjusting frequency misalignment or frequency error. This temporary correction is known as Automatic Frequency Control (AFC) or Automatic Fine Tuning (AFT).
LocusUSA has developed a patented technology to determine how much AFC correction is being applied to a subscriber radio in real time while the radio is deployed in the field. The DiagnostXâ„¢ AFC Meter measures the temporary AFC adjustment by capturing and analyzing all control channel transmissions from the radio.
DiagnostX provides an evaluation of the radio based on specific metrics including Frequency Error. Sometimes a radio will show as being within spec according to pre-set DiagnostX thresholds. The DiagnostX AFC Meter will display what percentage of AFC is being engaged. This means that there is a temporary correction of Frequency Error of up to 1000 or 1500 Hz depending on the manufacturer. A radio that is extensively misaligned will experience issues connecting to the system. As the radio continues to drift further out of alignment AFC will no longer engage, resulting in a hard failure. A radio like this, even while temporarily appearing to be within spec, is a definite candidate for maintenance. The DiagnostX AFC Meter, the only tool available for identifying such radios, provides a report of the percentage of AFC engaged on all measured subscribers, listed by Radio ID. The AFC Meter is an add-on feature to the DiagnostX systems.