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Intermittent transponder

J

jeff beckley

Well Known Member
I have been told by ATC that my GTX 327 is intermittent. This unit is new and it is installed in a RV7A with the antenna located dead center under the seats.
The antenna I used is the short stubby type with the ball in the end.
My com antennas are a little farther back and positioned close to the sides of the fuse. The transponder antenna is no closer than 18" to any other antenna or metal.
Could I be getting a shadow effect? Could there be a problem with my selection of antennas or a better solution?
I am going to take the 327 in to our local radio shop to rule out a problem with that.
Thoughts?
 
check the antenna cable

Hi Jeff,

I had a similar problem with the transponder in my -9A. I had a bad connection at the antenna. In my case, it was a 90deg BNC connector, but check all the crimps on the cable ends.

Good Luck - I fly in to Ames and Ankeny quite often to see family, maybe I'll see you down there. Is DSM friendly to GA and RVs?
 
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You need to take the whole a/c to an avionics shop and have it checked in the a/c. Don't know how long it has been in but it is supposed to be checked by a repair station after install. FAR 43 app F and every 2 years there after. Anyway, a bad coax can pull the xpondr freq off. Running 1090 MHz through rg-58 coax is very suseptible to changing the frequency. This is usually reported as intermittant ops. As an avionics tech I have seen this many times. Hope this helps!

Jay
 
Thanks Jay. I have a shop located here on the field. I will taxi over there.

Pete.. Yes Des Moines is friendly to us RV'rs. I have given rides in my 7A to almost every one of the controllers there.
 
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