Harmonic detection
In moving mode, the Ranger EZ receives a large reflection from the road, which is used to compute the patrol
speed. Some situations, such as when guardrails or large signs are present, cause the signal to be excessively
large. This can sometimes cause a harmonic frequency of twice the patrol speed to appear. These signals would
normally be displayed as a target with a speed equal to the patrol speed and prevent the Ranger EZ from reading
the speed of real targets, but harmonic detection circuitry inside the Ranger EZ inhibits this. Unfortunately, the
harmonic detection circuitry also may reduce the range of actual target vehicles that are moving at the same speed
as the patrol vehicle. This is normal and can be avoided by patrolling at a different speed than the offending
targets.
If Ranger EZ suspect a harmonic speed may be present, but the signal is large enough that it may be a valid target,
Ranger EZ will display the target speed but simultaneously light the HAR (harmonic) LED on the in the Target
window.
Sensitivity and radar placement
The range of the radar is influenced by how it is mounted in the vehicle. Heater fans are moving targets and will
be picked up if energy from the antenna is reflected toward the fan. Ranger EZ has special software that is
designed to minimize the effects of fan pick-up.
However, it is also important to mount the radar antennas in locations that minimize this effect. To determine this
location, place the unit in stationary mode, turn the volume up, and open the squelch. This lets any target or
interference be heard. If changing fan speeds changes the audio signal, the fan is being picked up in that
mounting position; try to find a different location. Reducing the fan speed may also reduce the problem.
Reducing the range setting of the radar will also reduce the problem. If you have persistent problems with the
RANGER EZ reading the fan speed, call the factory for suggestions specific to your particular vehicle.
Power Source
Cigarette lighter receptacles have been the traditional source of power for traffic radar. However, poor grounding,
electronic ignition bleed over, and alternator noise in newer cars can combine to create an unacceptably high level
of ambient electronic interference. In some instances, an unusually noisy vehicle ignition/alternator noise can
result in false readings and/or reduce the range of the Ranger.
If problems with EMI pick-up from the 12-Volt power are suspected, it is recommended that a shielded cable be
run from the battery directly to an auxiliary receptacle installed under the dash or on the console. This should
effectively eliminate any power source problems.
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