ELT trips on during transmit...

[Let'sgoflying!]

only when surrounded by metal (hangars)
only on comm2

What’s with that?

 

[denverpilot]

Reflected RF getting into the remote or main controls and being rectified into a DC current that trips the button would be by guess. And it shouldn’t do that. It’s broken.

 

[Let'sgoflying!]

Thanks.
I'll wrap it with foil.

 

[Dan Thomas]

Foil won' help. The RF is getting into the remote wiring. Get a snap-together ferrite core and wrap the elt's remote cable through it a couple of turns. Right close to the elt.

 

[Let'sgoflying!]

Foil won' help. The RF is getting into the remote wiring. Get a snap-together ferrite core and wrap the elt's remote cable through it a couple of turns. Right close to the elt.

Twas a joke. Designed to tease out a real solution (which worked!). Thanks - might give it a try Dan.

 

[flyingron]

Don't transmit in hangars?

 

[Let'sgoflying!]

Or between rows of hangars

 

[jimmyjack]

http://www.aircraftspruce.com/catalog/avpages/tednotch.php?clickkey=1242064

 

[Let'sgoflying!]

http://www.aircraftspruce.com/catalog/avpages/tednotch.php?clickkey=1242064

a) it goes inline with the comm antenna, right? (not the elt antenna)
b) what connects to the vertical part, if anything, in that picture?
c) thanks

 

[flyingron]

That filter (yes, it goes on the output of the comm radios) probably won't help the ELT issue. I can almost bet that it's the fundamental frequency that's messing things up. Dan's answer was most likely the correct one. RF into the remote wiring. It's pretty cheesy stuff and the ferrite should likely help.

But before you go crazy, check one thing: I'm betting this is either an ACK or AK ELT? Put a fresh battery in the remote. The thing gets kind of loopy when that battery starts to go (and while everybody is overly concerned over the batteries in the ELT itself, nobody seems to often check the remote battery).

 

[wsuffa]

I would also spend the time to have the SWR tested on the Comm antenna. Things like a bad ground, bad antenna, or broke shield on the feed line can cause this.

And from personal experience AK ELTs can trip just because. My experience involved a bad remote.

 

[jimmyjack]

a) it goes inline with the comm antenna, right? (not the elt antenna)
b) what connects to the vertical part, if anything, in that picture?
c) thanks

a) Either or. I used this on a GPS signal loss issue that originated with an AmeriKing ELT. Ultimately, it required a filter on both the comm and the ELT. that's the most common result. This may or may not work for your issue, but it's worth a shot.

b) Nothing, I imagine that's the capacitor/resistor/windings? of the filter itself.

c) You're welcome.