When radar detectors proved easily capable of sniffing out radar from miles away, radar gun manufacturers responded by producing instant-on radar or unoffically called "Pulse" radar. In the instant-on mode, the radar's transmitter is placed on hold, ready to fire but not yet producing a signal for detectors to hear. The officer waits until his target is very close (brings a new meaning to "wait till you see the whites of their eyes") then releases the radar from stand by mode and gets a speed reading within a second or so (pulse). In this situation, no detector offers much warning.
There are guns out there that operate just like the instant-on guns of the past but with a very tough twist - POPTM mode! This gun is a normal K and Ka band radar gun detectable by most radar detectors made in the past 30 years, until this gun is placed in POP mode. When the gun is in POP™ Mode and activated, a brief burst of energy, less than 1/15 of a second, is transmitted and the vehicle's speed is quickly acquired. A detector without POP™ Mode detection capability cannot respond to this brief transmission.
- When traveling in unfamiliar highways always try to find a vehicle which is traveling at the same rate or faster than you are and keep several car lengths behind them. This way the other vehicle can "flush out the radar".