Stalker ATR handheld - Sen and Range?


Learning to Drive
General User
May 17, 2020
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I have been playing around with the Stalker ATR handheld Ka gun that has stationary and moving modes. I read the manual for the device, but still a little confused on the sensitivity and range settings.

Range - options are 1-4. I tested this in both modes and can't tell the difference when getting readings of vehicles at different distances. Why would you ever change this from, lets say, 4 (max range), if it still gets a lock at close range? What benefit is there to changing this? Any idea what the actual ranges are between 1-4?

Sen - The manual explains this as: "The SEn key may be used to select a Patrol (Patrol Speed Select) Speed Threshold of either 5 mph or 20 mph. For example: SEn 4 20 is maximum range with a Patrol Speed Threshold of 20 mph and SEn 4 5 is max range with a Patrol Speed Threshold of 5 mph". Can someone explain this in more basic terms or give an example of the difference in 5mph and 20mph threshold? Maybe an example of what this means if I was patrolling at 50mph? It is just not sinking in what the 5 and 20 values mean in this example. Thanks for the help here.


PSL +5
Intermediate User
Aug 9, 2018
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I don't have an ATR, but do have an MDR. There are two separate settings on the MDR, Patrol Speed 5/20 and Sensitivity.

To understand why sensitivity is important knob to control, check this video out:

Note that they are picking up unwanted signals in the video (from that adjacent road), so they adjust the sensitivity to hone in on the patrol area.

For patrol speed sensitivity, this was implemented for moving radar. It's a filter that helps reduce the shadowing effect of the radar.

Moving radar works based on relativity. For that to be effective, it has to understand how fast the patrol vehicle is going in relation to the target. Usually you will have a VSS cable that will feed the speed from the OBD signal into the radar gun over serial interface, but when this cable isn't present your radar does this by deflecting signals off of the ground and using that ground as the reference point to display your speed.

When moving at slower speeds (say 5mph) it's easier for the radar to confuse a slow moving vehicle for ground deflections, so this extra filter is in play to help with low speed patrol.
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