I need a new ELT, which one do I get?

Gary Ward

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The old Dorne & Margolin ELT in a 1980 C172 quit working. The battery is good but no transmit while testing.
Guess I need a new one? Which one should I get that will mount where my old was?

TIA for any help with this.
 
I picked up an ACK-04 and am happy with it. Coupled it to my GPS so position reports are enhanced. I think the mount has to deflect no more than .1 inches when a 100 pound force on it. You will need to look at the installation instructions for the details
 
I ended up getting an Artex 345 rather than the ACK-04 when I was trying to decide which to get. Seems like those are the two most popular I was reading about. I didn't like that the ack has three different batteries I had to document and remember to replace, whereas the artex just has one battery good for 6 years. Expensive to replace, but oh well. Like the ack, the 345 also has the capability to couple to an external GPS unit for more accurate position reporting. 1.5 years with the Artex in the plane and so far no false activations (no valid ones either hah) or other problems.
 
I would get one with internal GPS and you’ll need a new antenna and probably a new little control panel. So install may not be as cheap as you might think.
 
ACK E-04 in one plane, Artex ME406 in the other. The brand makes no difference to me as long as it works if/when I need it to.

The ELT is supposed required to be mounted to structure. If your mount is riveted on to a skin it'll need to be moved.
 
Avionics techs I spoke with do not recommend ack due to false triggering issues. Seems the vhf transmissions set off the elt. Ack has added a filter to the rf side, but it still seems to be a problem… or so I hear. Ack would be the easiest upgrade for me. Any more feedback on the ack E-04?
 
Never a problem with my ACK, except when I set it off two different times while working on the plane. I got called very quickly both times and RCC knew exactly where I was, so knew there was no emergency. Clearly mine works!

PS- the second time I was parked inside my hangar. No issue with signal out.
 
I would get one with internal GPS and you’ll need a new antenna and probably a new little control panel. So install may not be as cheap as you might think.

Finding this out, my AP found the ELT not working but sounds like a job for my avionic shop to install it?
 
The panel switch is required. No need for internal GPS. GPS enabling isn't required but is easily accomplished using typical panel mounted or handheld GPS. A mechanic should be able to do the install easily.
 
I picked up an ACK-04 and am happy with it. Coupled it to my GPS so position reports are enhanced. I think the mount has to deflect no more than .1 inches when a 100 pound force on it. You will need to look at the installation instructions for the details
Thanks for heads up on mounting, it looks like my old one is mounted on the skin? I think I am going to call my avionic shop in the morning.
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The panel switch is required. No need for internal GPS. GPS enabling isn't required but is easily accomplished using typical panel mounted or handheld GPS. A mechanic should be able to do the install easily.
I/we do a lot on the plane our self's(my AP and I) but so far only one guy at the avionic shop has worked on my panel. He was the first one into it since it was new in 1980, he mentioned how nice it was to work on something original no modifications. I would like to keep it that way.

Weird I know, I used to be the guy to install your car stereo years ago...lol
 
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I would just put a 121.5 ELT back in. If I wanted more I would get a plb.
 
I recently installed the ACK-04 in my vee tail. You need to run a twisted pair and the flat ribbon cable from the rear fuselage to the instrument panel to interface with the panel mounted ELT remote and to send gps data and pwr to the ELT. If you do not have a panel mounted gps, there is an option to install a stand alone gps receiver if I remember correctly, or you can mount it minus gps input.

If I was not already doing another avionics install at the same time, I would not have taken out all the floor boards since my old ELT still worked, but was only 121.5 mhz.

I have my old ELT, with a battery good till 2024 on my bench.
 
Maybe a stupid question...where can I find one. Can you buy em new?

Are you wanting to know where you can find a new 121.5 ELT or a PLB?

As far as I know, the 121.5 ELTs are no longer available new, so if you want to go back with the same thing you'll be looking for a used replacement. When I went looking for the most budget friendly 406 ELT, I found it to be the ACK unit. A panel mounted remote is required with all the new ELTs, so I would anticipate having to install one.
 
Maybe a stupid question...where can I find one. Can you buy em new?
new 122.5, no. Not since circa 2019 it appears. New to you, why yes, yes please. I would check eBay, aircraft salvage places such as Wentworth, etc.
 
Like buying a 1990s flip phone. It might make you feel good to carry it but it won’t work when you need it. Pony up and buy a better piece of equipment. Nothing about a 406 install is difficult.
 
I have an ACK 04. Installed about 18 months now. 2 false activations so far... called ACK for advice. They said they needed detailed photos of my install, lots of other info before they could begin to assist me... decided to wait for the next false activation. :)
 
I have an ACK 04. Installed about 18 months now. 2 false activations so far... called ACK for advice. They said they needed detailed photos of my install, lots of other info before they could begin to assist me... decided to wait for the next false activation. :)
Did you install it yourself?
I plan to get my avionics shop to do mine since it is a little more involved than my old 121.5 elt.
Taking the plane over there this coming Monday, my bi annual IFR check will be done at the same time.
Thanks for everyone’s input. Gary
 
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Both Artex or ACK are good. I bought an ACK-04 in 2017 connected to my GPS. Went with ACK because they were less expensive and made in my home town. No false activations.

Look at battery replacement costs.
 
. I would like to keep it that way.
FYI: the remote switch only needs to be seen and operated by the PIC from their seat which you can define to meet the TSO requirement. So keeping your panel "clean" can still be an option. But any unit replacement would need to be relocated from your 121 location to meet the same TSO load requirement.
 
FYI: the remote switch only needs to be seen and operated by the PIC from their seat which you can define to meet the TSO requirement. So keeping your panel "clean" can still be an option. But any unit replacement would need to be relocated from your 121 location to meet the same TSO load requirement.
Thanks for the info.
This is why it is going to the avionics shop for the install because I don't think my AP mechanic is up on this new 406 requirements and he is very busy now. Turning into a expensive annual inspection...have anyone heard that before? lol
 
The panel switch is required. No need for internal GPS. GPS enabling isn't required but is easily accomplished using typical panel mounted or handheld GPS.
But then you have 2 points of failure, GPS and ELT….and the wiring between them.
 
Every pilot I know uses a simple handheld to enable their ELT. Never heard of a failure. Mine works perfectly, as proven when both inadvertent beacons had my location pinpointed perfectly. If yours has a history of failing? Find a better mechanic.
 
I don't think my AP mechanic is up on this new 406 requirements
The only main difference now is the remote switch and mount deflection check. All 406 OEM install instructions cover this and are pretty straight forward. No reason you couldnt do it under supervision and have the shop just interface the GPS if thats your plan.
 
Did you install it yourself?
I plan to get my avionics shop to do mine since it is a little more involved than my old 121.5 elt.
Taking the plane over there this coming Monday, my bi annual pitot static check will be done at the same time.
Thanks for everyone’s input. Gary
No, I had it installed by my mechanic. Very simple install. Bracket for ELT mounted to airframe in cargo area (oriented correctly), short coax run to the antenna, and remote head mounted in armrest. No external GPS connection.
 
The only main difference now is the remote switch and mount deflection check. All 406 OEM install instructions cover this and are pretty straight forward. No reason you couldnt do it under supervision and have the shop just interface the GPS if thats your plan.
I am concerned about the mounting since my old one is mounted on the flexible outer skin of the plane. So I will get their input on where it should mount. I have G 650 GPS in the panel that they installed back in 2018 so I would expect them to wire the elt to that?

I am taking the plane to the avionics shop with the interior gutted with only the pilots seat in place to save me the labor of them doing it since I already had it out and I am particular on the right screws being put back in the the right places.
 
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Every pilot I know uses a simple handheld to enable their ELT. Never heard of a failure. Mine works perfectly, as proven when both inadvertent beacons had my location pinpointed perfectly. If yours has a history of failing? Find a better mechanic.
Remember it has to work after a crash…which means GPS electronics must be operational and have power…you’re betting a handheld rigged up will still be operational? Might as well forget the ELT, and buy a PLB.
 
No, the GPS position last reported to the ELT is saved. When the ELT sends it's initial burst the position location is transmitted with it. The big advantage of GPS enabling is it sends the position in the first burst. Without the GPS information it takes several satellite passes to resolve the position, or about 45 minutes last time I visited RCC. Not all airplanes survive post-impact for 45 minutes (sinking, burning, etc.) If I believe a crash is immanent? I'm using the panel switch to transmit before the event plays out. If all goes well? I'll call RCC on my sat phone and tell them to disregard. Their number is speed dial #1 on my sat phone.
 
2829502C-841F-4C87-A510-30422F1FB4CB.jpeg 9A58B8E0-7733-4238-B43A-C90F0069A61A.jpeg Idecided on a Airtex 345 to replace my old elt.
Avionics shop installed and checked it out.
I got a email and text when he tested it.
Whole new ballgame with this deal.
Yea it has a 6 year battery but can only handle 1 hour of testing. Was told each time you hit that test button it uses a minute or two of your 60 minute battery. Get to 60 minutes and it is time for a new battery which is not cheap.
So won’t be testing it hopefully until next annual.

I had to register with the NOAA, they got my number and 2 of my closest friends.lol
Dropped it off Monday morning and it was ready to be picked up Wednesday morning. Cost some labor to have it installed but none of it was to remove or re install interior.
 
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Scott said they had problems with both types 406 elt we talked about in this thread. It was years ago and said these new ones are trouble free so far. Time will tell…
 
View attachment 109569 View attachment 109568 Idecided on a Airtex 345 to replace my old elt.
Avionics shop installed and checked it out.
I got a email and text when he tested it.
Whole new ballgame with this deal.
Yea it has a 6 year battery but can only handle 1 hour of testing. Was told each time you hit that test button it uses a minute or two of your 60 minute battery. Get to 60 minutes and it is time for a new battery which is not cheap.
So won’t be testing it hopefully until next annual.

I had to register with the NOAA, they got my number and 2 of my closest friends.lol
Dropped it off Monday morning and it was ready to be picked up Wednesday morning. Cost some labor to have it installed but none of it was to remove or re install interior.

The Artex 345 is a good choice but you may want to have a word with the avionics shop. The avionics shelf/rack or whatever they call it is not a proper spot to mount a 406 ELT. There are limits to the deflection found in the install manual and it needs a dedicated shelf or mount tied into structure. Also the buzzer has two ways to mount it, either using long screws or a with a hole and the top ring secured, not tyrapped onto the connector wiring.
 
The Artex 345 is a good choice but you may want to have a word with the avionics shop. The avionics shelf/rack or whatever they call it is not a proper spot to mount a 406 ELT. There are limits to the deflection found in the install manual and it needs a dedicated shelf or mount tied into structure. Also the buzzer has two ways to mount it, either using long screws or a with a hole and the top ring secured, not tyrapped onto the connector wiring.
I believe it is mounted to the structure of the plane? Please show me a picture of how it should be mounted if it is incorrect .
The buzzer is mounted like that so it is easy to move with the ELT. I would not want it mounted solid somewhere else and have to to put more holes in my plane and have to unbolt it for service.

please show me how it should be mounted so I can share it with my avionics shop. Thanks
 
I believe it is mounted to the structure of the plane? Please show me a picture of how it should be mounted if it is incorrect .
The buzzer is mounted like that so it is easy to move with the ELT. I would not want it mounted solid somewhere else and have to to put more holes in my plane and have to unbolt it for service.

please show me how it should be mounted so I can share it with my avionics shop. Thanks

Once a shelf is fabricated and is mounted you can use anchor nuts so that the elt bracket and buzzer can simply be screwed onto the shelf. This is on a 172. Shelf is tied to structure in multiple spots with rivets.

The old shelf that the glideslope receiver was on and where your ELT is mounted is not as stable and can move more than the installation instructions allow.
 

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Mine is mounted to an .070" thick channel that spans the two bulkheads and picks up at least five -4 rivets at at each end, and the lays over the existing "avionics shelf"
 
Once a shelf is fabricated and is mounted you can use anchor nuts so that the elt bracket and buzzer can simply be screwed onto the shelf. This is on a 172. Shelf is tied to structure in multiple spots with rivets.

The old shelf that the glideslope receiver was on and where your ELT is mounted is not as stable and can move more than the installation instructions allow.
Thanks for the pictures!
 
Artex service or lack there of!
On last annual in May the Artex did not activate with remote switch. The mechanic swapped with another like unit and determined the ELT was the problem. So it was sent back to Artex for repair. It is now September 30 and still no ELT. Last week checked with shop and they said they had three Artex units they have sent in and none have come back. The mechanic said they have called every couple of weeks and get stonewalled.
Anyone else having a problem with Artex ""Support""?
 
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