G'day Mick - I will get out the cleaning kit before the next flight . Will report results

Peter

oldmick wrote:
G'day Peter,

You will probably here from Zaon on this one as it sounds like a classic case of dirty transponder antenna.

The attenuated signal tricks the MRX into thinking it is another transponder further away than the ships own unit.

Good luck
Mick

Interesting. . .I tried out my new MRX today and over a distance of 60 nm it displayed an alert that varied from .6 to .8 nm away and usually +200 to +400 feet above, with a few 00 thrown in. . .at first I did a bit of maneuvering (as you can imagine when seeing such an alert), but it became clear pretty quick that there was no traffic there, and the ghost traffic seemed to fly pretty nice formation with our aircraft all the way to the destination.

I had thought it was a defective unit, but perhaps it's what you suggest!

-Brett

And if you had the audio output feed into your headset then you would have been driven crazy by a non stop alert - "Caution, traffic, check closure" repeated non-stop for 60 nm

Peter Mundy wrote:
And if you had the audio output feed into your headset then you would have been driven crazy by a non stop alert - "Caution, traffic, check closure" repeated non-stop for 60 nm

Oh I could hear it beeping. . .I turned the volume all the way down though. The only reason I left it on for a bit was since we had just picked up flight following I wanted to see how it responeded compared to what ATC said when we DID approach traffic, but sadly it never reported any threats even a few that were fairly close. . .I power cycled it a couple times, and verified that it was entering flight mode, but it became pretty clear that it wasn't working corectly.

I'll take one more flight with it in a different plane (this was a 172)before casting judgement.

I wanted to post here that on a subsequent flight in a different airplane, and after cleaning the transponder antenna, the unit did work properly. Now I guess I just need to try that with the plane I tested it in first to be certain it's just a dirty transponder antenna. If so I guess transponder antenna cleaning will need to be part of my pre-flight routine.

I'm flying a Shorts 360 and 01/07 had the same problem at 20,000ft, it showed on more than one occasion target 500ft below.