A LONG-RANGE, OVER-THE-AIR RADIO WAVEFORM ANALYZER
A LONG-RANGE, OVER-THE-AIR RADIO WAVEFORM ANALYZER
AFC Meter
AUTOMATIC FREQUENCY CONTROL (AFC) METER
Two-way radios can drift out of alignment over time, even when they appear to be operating normally. Automatic Frequency Control (AFC) can temporarily correct that drift, masking an underlying issue until reliability is affected.
The DiagnostX AFC Meter reveals how much correction is taking place, giving agencies visibility into radios that may be at risk.
AFC Meter
AUTOMATIC FREQUENCY CONTROL METER
Most land mobile radios incorporate an embedded technology that aids the radio in adjusting frequency misalignment or 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 applied to a subscriber radio in real-time while the radio is active in the field.
The DiagnostX AFC Meter measures the temporary AFC adjustment by capturing and analyzing all control channel transmissions from the radio.
SEE WHAT THE AFCE METER REVEALS
IDENTIFY FREQUENCY DRIFT BEFORE FAILURE
DiagnostX evaluates frequency stability to reveal how much Automatic Frequency Control is correcting a radio’s frequen-cy error. As correction increases, the AFC Meter provides an early indication that a radio may be drifting out of alignment.
Results are displayed by Radio ID, allowing technicians to quickly identify which radios should be evaluated for service.
DiagnostX AFC Meter Explained
BENEFITS
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 AFC Meter will display how much 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 AFC Meter, the only tool available for identifying such radios, provides a report of AFC engagement on all measured subscribers, listed by radio ID. The AFC Meter is an add-on feature to the DiagnostX system.
TECHNICAL BACKGROUND
Radios contain oscillator circuits that can drift over time. These oscillators are affected by factors like voltage, aging electronics, battery power, temperature, environment, and mounting conditions, leading to detuning, and communication degradation.
This is where Automatic Frequency Control (AFC) comes in; it temporarily controls and corrects the oscillator drift of a unit until it is turned ‘off’. AFC works within limits to address these variables, hiding the underlying issue until communication failure occurs.
