How far can I pick up an officer's radar gun?

Excluding instant-on radar, you can get enough range to slow down before the officer detects you.
We do not publish range in miles or feet due to the various types of radar in use (high power, low power, pulse). If we advertised 1.5 mile range and you came across a low powered radar gun you may only get 800 feet, for example. If that happened, you might get the impression that the detector may appear to be defective when in fact, it was providing detection for the type of radar that was transmitted.