I believe the addition of a Radar On/Off button on the fleet control panel would be a great addition. Why, you ask? Why would you ever want to turn radar off, you wonder? Well, you might consider turning it off if it gave away the precise position of your fleet to have the radar operating. The idea is that a fleet with an operating radar would display an icon on the clipboard to both friendly and enemy players. With the radar shut down, only friendly players would see an icon.
An operating radar is visible at far greater range than it can detect an aircraft, especially the big, long-range radars carried aboard ships. The down side of turning it off is you will not get raid warning of an approaching aircraft. However, if you're on the ropes (or in a scenario), it might be better to stay hidden. Another useful gambit is to shut down the radar while you're moving it withing striking range of an enemy fleet or position. Yes, you'ld still get a sector bar when someone launches, but that only hints that a carrier might be present, and doesn't give it's exact location.
This is historically and realistically in line with how fleets operate. RF direction finding was a common enough skill, particularly later in the war. Of course, intercept of radio chatter was also a common way to find ships, planes, and land forces; however, this would be much harder to emplement in AH. It would be cool if sector bars only appeared under certain conditions, such as use of the radio or flying at certain altitudes.
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Sabre (a.k.a. Rojo)