Because the FAA seems to want to lay its mitts on everything that’s bolted or wired into an airplane, an alternate universe of portable devices has evolved, including portable traffic systems that purport to scan the airspace to see traffic that the pilot might not. These have become ever more sophisticated and although no one claims they’ll go toe-to-toe with TCAS system, buyers find that portables have merit.

Zaon’s XRX has a protruding onboard antenna, but the device is small enough to easily find a home on the glareshield.

The latest comes from Zaon Flight Systems and it’s called the XRX. It’s the first portable unit that takes a stab at both the accurate ranging and azimuth display that has heretofore been limited to expensive panel-mounted gear. Although Zaon is itself a…