by James Oates » Wed Sep 11, 2013 1:35 pm
I'm probably in the middle of opinions. I have an XRX on a 496 as well. It's good for being far out enroute cross country(both because that's where you hit ADS-B holes{see below}, and because of less traffic). It seems that it gives good indications in that environment.
In a place like the LA basin it's close to useless. Not because it doesn't detect a valid aircraft here and there(I do notice it alerts me to lower flying helicopters which we have a lot of). More because of the previous mentioned limitations. Basically, it gives too many 'less than' accurate indications to be all that reliable.
Bottom Line(assuming proper install, no issues with own transponder, etc.):
-the XRX first detects that there is traffic
-then 'should' give a reasonable estimate of altitude
-and finally gives a very 'rough' idea of direction
In heavy traffice enviroments, you will find a lot of returns that bounce all around your plane, and often are off in direction by 90 degrees or more.
*ADS-B holes, IMHO - seems like the XRX is good for getting what might be bounces off of someone elses active TCAS when ATC radar is too far or shadowed to get the same return, or you are too far/low to get ADS-B back up from them.