Cracked xponder antenna

Bavafa · #1 07-19-2010, 09:39 AM

I was washing the belly of my plane that I noticed a 2" thin crack in my x-ponder antenna (Comant CI-105). The transponder is operating with no issue (have not dropped off radar yet). I was wondering any one has had this issue and if there is a recommended repair for it. I was thinking of lightly sand it and put two or three layer of glass on it from keeping it to grow or break off completely. Would two or three layer of glass block any of the signals?

sf3543 · #2 07-19-2010, 10:40 AM

I'd just clean it real good with some alcohol and let some super glue wick into the crack.
The crack is probably ok as is, but sealing the crack would prevent further cracking.
Anyway, that's what I would do.

dpansier · #3 07-19-2010, 12:19 PM

I would reccomend the fix Steve mentioned above, wicking some Super Glue into the crack and a few wraps of black electrical tape till it is bonded.
It is important to keep moisture out of the antenna internals, the Super Glue should do this.

I expect Comant will not reccomend a field fix because they would have a difficult time insuring the antenna meets the TSO after the fix.

Another thought, I've had a few request about painting the transponder antennas I produce, I have tested several types of paint and have found Krylon "Fusion" paint for plastic to work well on the transponder antennas. A medium covering coat has no noticeable electrical effect on the antenna performance as measured by my lab equipment.

The paint in combination with the Super Glue should have the antenna looking and performing like new.

Bavafa · #4 07-19-2010, 03:19 PM

Thanks for the suggestions, I found out that my CI-105 is still under warrenty and planning on pulling it and sending it to Comant and have them deal with it. I don't know if it is repairable or they would replace it but this way it would hopefully last longer then my field repair attempts.

Regards

az_gila · #5 07-19-2010, 07:58 PM

...so use a super glue or MEK based liquid glue that works on ABS type plastics - or a epoxy made for plastic (see Home Depot glue display aisle)

I did this and it's held up for several years and still going...

LincT · #6 07-20-2010, 09:23 AM

Any reason you all chose to go with the molded/fiberglass/faired/streamlined config. over the stainless stick w/ nub? I'll be deciding which to go with soon & would appreciate benefit of your experiences.

Thank-You (90% & 90% to go)