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ELT false activation
I turned my ACK E-04 ELT to armed for the first time today with the intention of testing the GPS data as per the ACK manual and as soon as I turned the switch to armed it started sending a distress signal. Called search and rescue and made them aware I am OK. Also Im in contact with ACK and they are helping me troubleshoot but dont have an answer yet they think it might be EMF. To that point my elt is mounted in the factory position (under turtle deck on the right side), My comm antenna is mounted on the plate behind the turtle deck, my ADSB/XPDR antenna is on the right plate behind the seat on the bottom of fuselage, Remote XPDR is on the left side of the turtle deck opposite the ELT but same position. The remote for the transponder is on the panel which means the cable is run under the center console with all the other things that go to the panel. I figured Id see what you guys thought or if any one has run into this issue. I assume everyones set up is similar from a wire routing position of components standpoint.
Thanks for the help!
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Re: ELT false activation
Joe - have you checked the cable for a short? Were all other instruments off when the trouble occurred?
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Re: ELT false activation
I did not check the cable for a short, seems unlikely but Ill take a look. I forgot to mention that it is intermittent. The first time it send the distress almost immediately, others it takes a few minutes. Once I had it armed and when I turned on the avionics it activated immediately, other times it does not. That being said, it does not activate when the avionics are all off. So I know its something interacting with it. But I cannot figure out what would cause it to be intermittent. I would think it if activates when I turn everything on it would always do so but that doesn't seem to be the case.
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Re: ELT false activation
I’d disconnect the remote switch and try it again.
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Re: ELT false activation
Test the theory if it is EMF. I have heard the transponder is very noisy and can cause issues. Have you tried turning off the transponder? Shut it off on the VPX and see if it the ELT activates again? I ran my ELT phone cable on the right side of the fueslage away from all other wires. How involved would it be to reroute you wire away from the transponder antenna and transponder antenna wire ?
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Re: ELT false activation
Joe,
Do you have a Garmin G3? In the past I had a friend that had a G3 and it tripped his ELT. I believe it had to do with the proximity of the transponder antenna coax. If you are having more issues, I can contact him to find the specifics. It has been a few years since he relayed the issue to me and I don't remember all the details.
Ralph
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Re: ELT false activation
Thanks all, so far it looks like it may be the routing of the remote wire. I unplugged and seems to be working now. I have new wire on the way because rerouting would be a PIA! But I can cut the old wire and pull out no problem. So Ill try along the right side and see what happens. ACK also suggested tin-foiling (wrapping) the ELT to keep stray EMF out.
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Re: ELT false activation
Right there with you on the ACK. I replaced my AmeriKing with an ACK in May and have had false triggers ever since. I am getting to know the Air Force guy pretty well. I had heard about the remote wire collecting signals and causing false triggers. Mine typically would go off when turning on the master. But at times it would wait until I was in the air. Likely a response to the radio or even the trim. When the remote is disconnected it will not trigger.
I pulled my remote cable (essentially an old style analog phone cord) and shielded it with aluminum then re-routed it away from all other wires. It did not help. As soon as the master was turned on the ELT triggered. Thinking I had done about all I could I called ACK. Have to say I am not too impressed. They sent a checklist to fill out. Their plan is to isolate what is causing problems with their snowflake system and then having me adjust/remove the offending device. Not sure that is going to be possible. They seem to have a very low impression of Experimental aircraft.
My next move might be to shield the switch. Then ask them for a replacement switch. I am also concerned about the battery. I have been able to turn it off quickly when it triggers, essentially what a test would be. But it is now adding up. Based on their responses the possibility of them replacing the battery seems remote.
Last ditch I may go without connecting the remote. I have a PLB that I wear as well.
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Re: ELT false activation
It happened to me once with my ACK-04 ELT. ACK said it was most likely being caused by my Garmin transponder. I ended up making my own shielded cable to replace the telephone cable. I also rerouted it away from the transponder antenna cable and have not had a problem since.
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Re: ELT false activation
Joe,
What was your final fix for this ELT issue? I seem to be having the same problem with my transponder causing my ACK E-04 to activate.
I have a GTX 335 with the antenna mounted to the plate behind the copilot seat and the ELT mounted to the the plate behind the pilot seat. I have ran shielded cable to the ELT remote with a single ground on the shield at the panel. I also tried shielding the ELT with foil with no help. I've even tried moving the ELT to different locations to try and get more separation from the transponder antenna which seems to help a little but I still get random ELT triggers. I know it is being caused by the RF radiated from the transponder antenna because the problem goes away if I connect an RF dummy load on the transponder. I running out of ideas and was wondering how you solved your problem.
Thanks,
Brad